03 Cobra P0405 - Sensor A Circuit Low

[Boogie Chillin]

I figured I'd post this for posterity and get some suggestions:

I put the EGR back on. I had to buy a EGR Tube and valve from Ebay. Mounting that tube w/ aftermarket LT's and S/C was pretty rough. But it is back on.

I have a P0405 Code - EGR Sensor A Circuit Low
Read more at: P0405 Exhaust Gas Recirculation Sensor A Circuit Low

So, with a volt meter and a test lamp, I tested the DPFE and EVR for functionality. I have two Motorcraft DPFE's. Here are the results:

New DPFE Connected:

KOEO -
DPFE Brown/Green 1.016 V SIG
DPFE GREY RED 0.038V SIG RET
DPFE Brown/White 5.034 V VREF
EVR Left Wire - 11.92 V CONTROL


EO -
DPFE Brown/Green EO [IDLE ~800ish rpm]- 1.091-1.186 V

EVR Left Control Wire 12.54-13.39 V

Old DPFE Connected:

KOEO -
DPFE Brown/Green 1.030 V SIG
DPFE Brown/White 5.034 V VREF
EVR Left Wire - 11.92 V CONTROL


EO -
DPFE Brown/Green EO [IDLE ~800ish rpm] SIG
1.103-1.199V
AVG: 1.136V

EVR Left Control Wire 12.54-13.39 V

So between KOEO and EO, I am seeing around a 0.1 V increase in the DPFE signal. I think that puts it out of spec at idle and throws a code (I read that it should be between .95 and 1.05V). At idle, the EGR Valve should be closed and the voltage should not change from KOEO, correct?

I'm guessing the EGR Valve pin may not be seating all the way(I did clean it w/ carb cleaner before installing it.)

I have a second valve, I just don't want to wrestle with the EGR tube again, especially if I am missing something simple.

I used the test light to actuate the EVR to ground. This caused the DPFE voltage to go up and the engine cut out. So, it looks like the EVR and DPFE are working.

Is there always a slight vacuum to the EGR Valve? Does the EVR shut 100% of the vacuum?

I unplugged the vacuum line from the EGR Valve and the DPFE voltage did not change. I also smacked the valve with a mallet. The DPFE started to bounce in and out of ~1.08-1.19V at idle.

So - I see four possibilities:
1. EGR Valve is not seating.
2. Something in the aftermarket tune? EGR option is turned on and has passed.
3. Bad seal on the valve gasket.
4. A bad electrical connection on the harness or PCM issue.

If you read this, wow you really like these Cobras. If you understood all of it, wow you really really like the Cobras.

Any thoughts are appreciated.

 

[kidds302]

whatever it is it looks like you have your work cut out for ya, I agree with those possible issues you've stated. only one way to find out IMO

 

[hotcobra03]

I had this code last summer..

I went to bone yard and got anothe sensor with both hoses to tube.
.

what brand is your 2nd dpfegr

 

[hotcobra03]

question..is the car tuned?

I had just played on mine..I had installed a 4lb lower.

went to change tune and when I did I ended up with many codes.
egr was 1 of them..

I thought there must be more to pulley tune than just pushing buttons,as if other items had to be deleated

 

[Boogie Chillin]

.

what brand is your 2nd dpfegr

Both are OEM Motorcraft.

question..is the car tuned?

I had just played on mine..I had installed a 4lb lower.

went to change tune and when I did I ended up with many codes.
egr was 1 of them..

I thought there must be more to pulley tune than just pushing buttons,as if other items had to be deleated

It is tuned. I have one tune with the EGR enabled.

 

[hotcobra03]

po405,,,see po1400

P1400 - DPF EGR Sensor Circuit Low Voltage Detected The EGR monitor checks the DPF EGR sensor signal to the PCM for low voltage. The test fails when the average voltage to the PCM drops to a voltage less than the minimum calibrated value. DPFEGR circuit short to GND
Damaged DPF EGR sensor
VREF short to GND
Damaged PCM
A DPF EGR PID reading less than 0.2 volt with the key ON and engine OFF or running, indicates a hard fault.

see pinpoint HE1

 

[hotcobra03]

HE1

2003 PCED OBDII SECTION 5: Pinpoint Tests

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HE: Exhaust Gas Recirculation (EGR) Systems HE: Introduction

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HE1 DTC P0405, P1400: DETERMINE PRESENT DPFEGR PID VOLTAGE
Key ON, Engine OFF.
Access DPFEGR PID.
Is DPFEGR PID voltage less than 0.2V DC?
Yes No
Fault is currently present. Key OFF. GO to HE2 . Fault is intermittent. GO to HE5 .

HE2 INDUCE OPPOSITE D.P.F. EGR SENSOR VOLTAGE
Disconnect D.P.F. EGR sensor.
Key ON, Engine OFF.
Is DPFEGR PID value between 4.0V and 6.0V DC?
Yes No
REPLACE D.P.F. EGR sensor. GO to HE3 .

HE3 CHECK VREF AND SIG RTN CIRCUITS FOR OPEN IN HARNESS TO D.P.F. EGR SENSOR
Measure voltage between VREF and SIG RTN circuits at the D.P.F. EGR sensor harness connector.
Is VREF voltage between 4.0V and 6.0V DC?
Yes No
Key OFF. GO to HE4 . GO to C1 .

HE4 CHECK DPFEGR CIRCUIT FOR SHORT TO GROUND AND SIG RTN IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect scan tool.
Disconnect PCM.
Measure resistance between DPFEGR and SIG. RTN circuits at the PCM harness connector.
Measure resistance between DPFEGR circuit at the PCM harness connector and battery (-) terminal.
Is each resistance greater than 10K ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

HE5 PERFORM WIGGLE TEST ON D.P.F. EGR SENSOR AND CIRCUIT WHILE MONITORING DPFEGR PID FOR A SUDDEN CHANGE
While monitoring DPFEGR PID, tap on the D.P.F. EGR sensor and wiggle the wiring while looking for a sudden change in value as an indication of an intermittent.
Is intermittent fault found?
Yes No
REPAIR as necessary. Unable to duplicate or identify fault at this time. GO to Z1 .

HE10 DTC P0406, P1401: DETERMINE PRESENT DPFEGR PID VOLTAGE
Key ON, Engine OFF.
Access DPFEGR PID.
Is DPFEGR PID voltage greater than 4.0V DC?
Yes No
Fault is currently present. Key OFF. GO to HE11 . Fault is intermittent. GO to HE19 .

HE11 CHECK DPFEGR CIRCUIT FOR SHORT TO PWR
Disconnect D.P.F. EGR sensor.
Key ON, Engine OFF.
Measure voltage between DPFEGR circuit at the D.P.F. EGR sensor harness connector and battery (-) terminal.
Is voltage greater than 10.5V DC?
Yes No
Key OFF. GO to HE12 . GO to HE13 .

HE12 CHECK DPFEGR CIRCUIT FOR SHORT TO PWR IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Key ON, Engine OFF.
Measure voltage between DPFEGR circuit at the PCM harness connector and battery (-) terminal.
Is voltage greater than 10.5V DC?
Yes No
REPAIR short circuit. REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ).

HE13 VERIFY SCAN TOOL COMMUNICATION
Connect jumper wire between DPFEGR and SIG RTN circuits at the D.P.F. EGR sensor harness connector.

Access DPFEGR PID.
Does a scan tool communication concern appear with the jumper wire connected?
Yes No
IMMEDIATELY REMOVE jumper wire. GO to HE19 . GO to HE14 .

HE14 INDUCE OPPOSITE D.P.F. EGR SENSOR VOLTAGE
Key OFF.
Disconnect jumper wire between DPFEGR and SIG RTN circuits at the D.P.F. EGR sensor harness connector.
Connect jumper wire between DPFEGR and VREF circuits at the D.P.F. EGR sensor harness connector.
Key ON, Engine OFF.
Access DPFEGR PID.
Is DPFEGR PID voltage less than 0.05V DC?
Yes No
REMOVE jumper. GO to HE15 . Unable to induce opposite signal. Key OFF. GO to HE17 .

HE15 CHECK VREF VOLTAGE TO D.P.F. EGR SENSOR
Measure voltage between VREF and SIG RTN circuits at the D.P.F. EGR sensor harness connector.
Is VREF voltage between 4.0V and 6.0V DC?
Yes No
REPLACE D.P.F. EGR sensor. GO to C1 .

HE17 CHECK DPFEGR CIRCUIT FOR OPEN IN HARNESS
Disconnect PCM.
Measure resistance of DPFEGR circuit between PCM harness connector pin and D.P.F. EGR sensor harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to HE18 . REPAIR open circuit.

HE18 CHECK SIG RTN CIRCUIT FOR OPEN IN HARNESS
Measure resistance of SIG RTN circuit between PCM harness connector pin and D.P.F. EGR sensor harness connector.
Is resistance less than 5.0 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR open circuit.

HE19 CHECK DPFEGR CIRCUIT FOR SHORT TO VREF IN HARNESS
Disconnect PCM.
Measure resistance between DPFEGR circuit and VREF circuit(s) at the PCM harness connector.
Is resistance greater than 10K ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

HE20 PERFORM WIGGLE TEST ON D.P.F. EGR SENSOR AND CIRCUIT WHILE MONITORING DPFEGR PID FOR A SUDDEN CHANGE
While monitoring DPFEGR PID, tap on the D.P.F. EGR sensor and wiggle the harness while looking for a sudden change in value as an indication of an intermittent.
Is intermittent fault found?
Yes No
REPAIR as necessary. Unable to duplicate or identify fault at this time. GO to Z1 .

HE21 CHECK FOR PRESENCE OF DTC P1405 WITH DTC P0402
Is DTC P1405 present with DTC P0402?
Yes No
GO to HE50 . GO to HE22 .

HE22 DTC P0402: CHECK FOR EGR FLOW AT IDLE WITH EGR VACUUM HOSE DISCONNECTED
Disconnect vacuum hose at EGR valve and plug hose.
Run Key On Engine Running (KOER) Self-Test.
Did KOER DTC P0402 appear or are you unable to run KOER Self-Test due to an engine stall or no start?
Yes No
Key OFF. INSPECT pressure hoses first for pinching and icing. If OK, REMOVE and INSPECT the EGR valve and EGR tube for signs of contamination, unusual wear, carbon deposits, binding and other damage. REPAIR as necessary. RECONNECT vacuum hose to EGR valve. GO to HE23 .

HE23 CHECK FOR EGR FLOW AT IDLE WITH EGR VACUUM HOSE CONNECTED
EGR vacuum hose connected.
Run KOER Self-Test.
Did KOER DTC P0402 appear or are you unable to run KOER Self-Test due to an engine stall or no start?
Yes No
Possible EGR flow at idle. GO to HE24 . Fault is intermittent. INSPECT pressure hoses for pinching and icing. REPAIR as necessary. GO to HE31 .

HE24 CHECK EGR SYSTEM VACUUM HOSES FOR INTEGRITY AND CONNECTION
Note: A pinched or plugged EGR vacuum hose can trap vacuum between the EGR vacuum regulator solenoid and EGR valve, not allowing the EGR valve to close.

Trace each vacuum hose from EGR vacuum regulator solenoid and verify that each hose is connected correctly (refer to vehicle vacuum diagram label).
Verify that the EGR valve vacuum hose is not pinched or plugged and is routed properly.
Are vacuum hoses OK?
Yes No
RECONNECT vacuum hoses. GO to HE25 . REPAIR vacuum hoses as necessary.

HE25 CHECK D.P.F. EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube).
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27 to 30 kPa (8 to 9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for 5 seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. RECONNECT D.P.F. EGR sensor. GO to HE26 .

HE26 CHECK FOR EGR FLOW AT IDLE WITH EGR VACUUM REGULATOR SOLENOID CONNECTOR OFF
Disconnect vacuum hose at EGR valve and connect hose to vacuum gauge.
Start engine.
While monitoring vacuum gauge, disconnect the EGR vacuum regulator solenoid harness connector.
The EGR valve requires vacuum greater than 5.4 kPa (1.6 in-Hg) to begin to open. If the vacuum reading remains greater than 5.4 kPa (1.6 in-Hg) after the EGR vacuum regulator solenoid is electrically disconnected, this would indicate a mechanical fault in the EGR vacuum regulator solenoid.
Does the EGR vacuum remain greater than 5.4 kPa (1.6 in-Hg) at idle even after EGR vacuum regulator solenoid is electrically disconnected?
Yes No
This indicates a fault in the EGR vacuum regulator solenoid. Key OFF. GO to HE27 . Key OFF. GO to HE26 .

HE27 INSPECT EGR VACUUM REGULATOR SOLENOID VENT FOR PLUGGING
Note: A plugged EGR vacuum regulator solenoid vent will not allow EGR vacuum to vent to atmosphere.

Disconnect EGR vacuum regulator solenoid vacuum hoses.
Remove EGR vacuum regulator solenoid vent cap (if removable).
Remove filter and inspect for blockage or icing in some cases.
With the EGR vacuum supply port plugged, apply 34 to 51 kPa (10 to 15 in-Hg) of vacuum directly to EGR vacuum regulator solenoid vacuum source port with a hand vacuum pump. If the vacuum holds or is slow to release to atmosphere, the EGR vacuum regulator solenoid vent could be plugged or restricted.




Is the EGR vacuum regulator solenoid vent or vent filter plugged or restricted?
Yes No
REPAIR EGR vacuum regulator solenoid as necessary. If unable to repair, REPLACE EGR vacuum regulator solenoid. REPLACE EGR vacuum regulator solenoid.

HE28 CHECK EGR VACUUM REGULATOR SOLENOID COIL RESISTANCE
Measure resistance across EGR vacuum regulator solenoid.
Is resistance between 26 and 40 ohms?
Yes No
GO to HE28 . REPLACE EGR vacuum regulator solenoid.

HE29 CHECK EGRVR CIRCUIT FOR SHORT TO GROUND IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect scan tool from DLC.
Disconnect PCM.
Measure resistance between EGRVR circuit at the PCM harness connector and battery (-) terminal.
Is resistance greater than 10K ohms?
Yes No
GO to HE30 . REPAIR short circuit.

HE30 CHECK EGRVR CIRCUIT FOR SHORT TO VREF
Measure resistance between EGRVR circuit and VREF circuit(s) at the PCM harness connector.
Is resistance greater than 10K ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

HE31 CHECK D.P.F. EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube).
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27 to 30 kPa (8 to 9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for 5 seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. RECONNECT D.P.F. EGR sensor. GO to HE32 .

HE32 CHECK D.P.F. EGR SENSOR VOLTAGE WHILE EXERCISING EGR VALVE
Key ON, Engine OFF.
View DPFEGR PID and make note of voltage.
Typical D.P.F. EGR sensor voltage with no EGR flow is between 0.2V and 1.3V DC.
Disconnect vacuum hose at EGR valve and plug hose.
Connect a hand vacuum pump to EGR valve.
Start engine.
Observe DPFEGR PID at idle and compare to the key ON engine OFF voltage. (A higher voltage at idle may be due to a non-seating EGR valve.)
Apply just enough vacuum to EGR valve to open it 7-10 kPa (2-3 in-Hg) without stalling engine and release vacuum. Repeat several times while observing DPFEGR PID. (DPFEGR PID voltage must increase as valve begins to open and return to initial value as vacuum is released. A slow to return voltage could be an indication of a binding or a slow-closing EGR valve.)
Does the DPFEGR PID voltage indicate an open, binding or slow-closing EGR valve?
Yes No
REMOVE and INSPECT the EGR valve for signs of contamination, unusual wear, carbon deposits, binding and other damage. REPAIR as necessary. Key OFF. GO to HE33 .

HE33 MONITOR EGR VALVE VACUUM WHILE WIGGLING EGRVR CIRCUIT
Note: An intermittent short to GND in the EGRVR circuit will cause the vacuum applied to the EGR valve to be higher than normal while the short is present. The vacuum available at the EGR valve at idle is normally below 3.4 kPa (1.0 in-Hg) and it takes about 5.4 kPa (1.6 in-Hg) for the valve to begin to open.

Remove hand vacuum pump.
Connect vacuum gauge to EGR valve vacuum hose.
Key ON, Engine RUNNING.
Observe vacuum gauge for an indication of a fault while performing the following:
Lightly tap on the EGR vacuum regulator solenoid; wiggle the EGR vacuum regulator solenoid connector and vehicle harness between solenoid and PCM. A fault is indicated by a sudden jump in vacuum reading.
Is intermittent fault found?
Yes No
ISOLATE fault and REPAIR as necessary. RECONNECT vacuum hose. Key OFF. GO to HE34 .

HE34 INSPECT EGR VACUUM REGULATOR SOLENOID AND VACUUM HOSES FOR POTENTIAL PLUGGING
Remove EGR vacuum regulator solenoid vent filter and inspect for contamination and excessive water absorption. (In cold climate, excessive water in filter could freeze and plug the EGR vacuum regulator solenoid vent.)
Inspect EGR vacuum hose for possible blockage or pinching.
Is EGR vacuum regulator solenoid vent or filter contaminated or vacuum hose plugged?
Yes No
REPAIR EGR vacuum regulator solenoid or EGR vacuum hose as necessary. Unable to duplicate or identify fault at this time. GO to Z1 .

HE50 DTC P1405: INSPECT UPSTREAM PRESSURE HOSE CONNECTIONS
Inspect upstream hose at D.P.F. EGR sensor and orifice tube assembly for disconnect or poor connection.
Is hose OFF or poorly connected?




Yes No
REPAIR as necessary. COMPLETE EGR Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles ). GO to HE51 .

HE51 INSPECT UPSTREAM PRESSURE HOSE FOR PLUGGING
Note: It is essential that ONLY the correct Ford service D.P.F. EGR sensor pressure hose be used.

Visually inspect upstream pressure hose routing. Hose must not be pinched or have dips in it where water could settle or freeze.
Remove upstream pressure hose and carefully inspect for plugging, water or leaks.
Is there a fault detected in the hose?
Yes No
REPAIR or REPLACE upstream pressure hose as necessary. COMPLETE EGR Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles ). GO to HE52 .

HE52 CHECK ORIFICE TUBE ASSEMBLY AND D.P.F. EGR SENSOR
Inspect the upstream connection on the D.P.F. EGR sensor for plugging or damage at the sensor.
Inspect the exhaust manifold side pressure pickup tube at the orifice tube assembly for plugging or damage.
Is the D.P.F. EGR sensor or orifice tube assembly plugged or damaged?
Yes No
REPAIR or REPLACE D.P.F. EGR sensor or orifice tube assembly as necessary. COMPLETE EGR Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles ). GO to HE53 .

HE53 CHECK D.P.F. EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube).
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27 to 30 kPa (8 to 9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for a few seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. COMPLETE an EGR Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles ). Unable to duplicate or identify fault at this time. GO to Z1 .

HE60 DTC P1406: INSPECT DOWNSTREAM PRESSURE HOSE CONNECTIONS
Note: If the fault is currently present, DTC P1408 will appear when running Key On Engine Running (KOER) Self-Test.

Verify EGR valve is securely attached and exhaust gasses are not leaking from the sealing surface.

Inspect downstream hose at D.P.F. EGR sensor and orifice tube assembly for disconnect or poor connection.
Is hose OFF or poorly connected?




Yes No
REPAIR as necessary. GO to HE61 .

HE61 INSPECT DOWNSTREAM PRESSURE HOSE FOR PLUGGING
Note: It is essential that ONLY the correct Ford service D.P.F. EGR sensor pressure hose be used.

Visually inspect downstream pressure hose routing. Hose must not be pinched or have dips in it where water can settle or freeze.
Remove downstream pressure hose and carefully inspect for plugging, water or leaks.
Is there a fault detected in the hose?
Yes No
REPAIR or REPLACE as necessary. GO to HE62 .

HE62 CHECK ORIFICE TUBE ASSEMBLY AND D.P.F. EGR SENSOR
Inspect the connections at the D.P.F. EGR sensor for plugging or damage.
Inspect the intake manifold side pressure pickup tube and orifice tube assembly for plugging, loose connection or damage.
Is the D.P.F. EGR sensor or orifice tube assembly plugged, loose or damaged?
Yes No
REPAIR or REPLACE D.P.F. EGR sensor or orifice tube assembly as necessary. GO to HE63 .

HE63 CHECK EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube).
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27 to 30 kPa (8 to 9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for 5 seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. Unable to duplicate or identify fault at this time. GO to Z1 .

HE70 DTC P0401: RUN KOER SELF-TEST
Run KOER Self-Test.
Did KOER DTC P1408 appear?
Yes No
Fault is currently present. GO to HE71 . GO to HE90 .

HE71 DTC P1408: RETRIEVE CONTINUOUS MEMORY DTCS
Note: If any DTC other than DTC P1406 appears, note the DTC and refer to Diagnostic Trouble Code (DTC) Charts in Section 4 after completing this Pinpoint Test.

Retrieve all Continuous Memory DTCs.
Is DTC P1406 present?
Yes No
GO to HE60 . GO to HE72 .

HE72 RUN KOER SELF-TEST WHILE MONITORING EGR VACUUM
Disconnect vacuum hose at EGR valve and connect hose to a vacuum gauge.
Note: Since the EGR vacuum hose is disconnected, ignore DTCs during this KOER Self-Test.

Run Key On Engine Running (KOER) Self-Test while monitoring gauge. Approximately 30 seconds into test, EGR flow will be requested for a few seconds. The vacuum at this time should increase above 5.4 kPa (1.6 in-Hg) to open the valve.
Does the vacuum increase to 10 kPa (3.0 in-Hg) or greater at any time during KOER Self-Test?
Yes No
The vacuum indicated is sufficient to open the EGR valve. Fault is unlikely to be in EGR vacuum control system. Key OFF. GO to HE73 . The vacuum indicated is insufficient to open the EGR valve. Key OFF. GO to HE80 .

HE73 INSPECT D.P.F. EGR SENSOR PRESSURE HOSES
Visually inspect both pressure hoses for reversed connection at D.P.F. EGR sensor or at orifice tube assembly.
Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle or freeze.
Inspect both hoses for leaks and blockage.
Inspect D.P.F. EGR sensor and orifice tube assembly for blockage or damage at the pickup tubes.
Is a fault detected?




Yes No
REPAIR pressure hoses as necessary. GO to HE74 .

HE74 CHECK D.P.F. EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube.)
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27-30 kPa (8-9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for 5 seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. RECONNECT pressure hoses. GO to HE76 .

HE76 CHECK EGR VALVE FUNCTION BY APPLYING VACUUM WITH HAND PUMP
Disconnect vacuum hose at EGR valve and plug hose.
Connect a hand vacuum pump to EGR valve.
Start engine.
Access DPFEGR and RPM PIDs.
Slowly apply 27 to 34 kPa (8 to 10 in-Hg) of vacuum to the EGR valve and hold it for 10 seconds. If engine wants to stall, increase rpm with throttle to maintain a minimum of 1000 RPM.
Look for the following:
EGR valve starts opening at about 5.4 kPa (1.6 in-Hg) vacuum indicated by increasing DPFEGR PID voltage.
DPFEGR PID voltage increasing until EGR valve is fully open. DPFEGR PID must read 2.5V DC minimum with full vacuum applied.
DPFEGR PID voltage steady when vacuum is held. If voltage drops within a few seconds, the EGR valve or vacuum source can be leaking.
Does the DPFEGR PID voltage indicate the EGR valve is operating as described in this test step?
Yes No
GO to HE82 . REMOVE and INSPECT the EGR valve for signs of contamination, unusual wear, carbon deposits, binding, leaking diaphragm and other damage. If EGR valve is OK, look for an obstructed EGR port in the intake manifold or plugged orifice tube assembly. REPAIR as necessary.

HE80 PHYSICALLY INSPECT ALL VACUUM LINES BETWEEN EGR VALVE, EVR AND VACUUM SOURCE
Inspect all vacuum lines for leaks, kinks, pinches, disconnects, blockage, misrouting or any physical damage.
Are any physical concerns present?
Yes No
REPAIR as necessary. Key OFF. GO to HE81 .

HE81 CHECK ENGINE VACUUM
Disconnect EVR vacuum hose at vacuum source.
Connect vacuum gauge to vacuum source.
Start engine.
With engine warm and at idle, monitor vacuum gauge.
Is the vacuum gauge steadily reading a minimum of 51 kPa (15 in-Hg)?
Yes No
Key OFF. GO to HE82 . ISOLATE possible base engine concern and REPAIR as necessary.

HE82 CHECK VPWR VOLTAGE TO EGR VACUUM REGULATOR SOLENOID
Disconnect EGR vacuum regulator solenoid.
Key ON, Engine OFF.
Measure VPWR circuit voltage at EGR vacuum regulator solenoid harness connector.
Is EGR vacuum regulator solenoid VPWR voltage greater than 10.5V DC?
Yes No
Key OFF. GO to HE83 . REPAIR open circuit.

HE83 CHECK EGR VACUUM REGULATOR SOLENOID RESISTANCE
Measure EGR vacuum regulator solenoid resistance.
Is solenoid resistance between 26 and 40 ohms?
Yes No
GO to HE84 . REPLACE EGR vacuum regulator solenoid.

HE84 CHECK EGRVR CIRCUIT FOR SHORT TO PWR IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Key ON, Engine OFF.
Measure voltage between EGRVR circuit at the PCM harness connector and battery (-) terminal.
Is voltage greater than 1.0V DC?
Yes No
REPAIR short circuit. Key OFF. GO to HE85 .

HE85 CHECK EGRVR CIRCUIT FOR OPEN IN HARNESS
Measure resistance of EGRVR circuit between PCM harness connector pin and EGR vacuum regulator solenoid harness connector.
Is resistance less than 5.0 ohms?
Yes No
RECONNECT PCM and EGR vacuum regulator solenoid. GO to HE86 . REPAIR open in EGRVR circuit.

HE86 CHECK EGR VACUUM REGULATOR SOLENOID VACUUM OUTPUT CAPABILITY BY GROUNDING EGRVR CIRCUIT
Disconnect vacuum hose at the EGR valve and connect to a vacuum gauge.
Key ON, Engine RUNNING.
With engine at idle, jumper PCM EGRVR circuit to chassis ground. If the EGRVR does not react within 2 seconds, an EGRVR fault may be present.
Is vacuum gauge reading 13.5 kPa (4.0 in-Hg) or greater within 2 seconds?
Yes No
REPLACE PCM (refer to section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPLACE EGR vacuum regulator solenoid.

HE90 INSPECT EGR SYSTEM FOR AN INTERMITTENT FAILURE
Visually inspect the EGR system for signs of intermittent failure.
Is a fault found?
Yes No
REPAIR fault as necessary. GO to HE91 .

HE91 INSPECT D.P.F. EGR SENSOR PRESSURE HOSES
Visually inspect both pressure hoses for reversed connection at D.P.F. EGR sensor or at orifice tube assembly.
Inspect both hoses for improper routing. Hoses should not be pinched or have dips where water could settle or freeze.
Inspect both hoses for leaks and blockage.
Inspect D.P.F. EGR sensor and orifice tube assembly for blockage or damage at the pickup tubes.
Is a fault detected?




Yes No
REPAIR pressure hoses as necessary. GO to HE92 .

HE92 CHECK D.P.F. EGR SENSOR OUTPUT BY APPLYING VACUUM WITH HAND PUMP
Disconnect pressure hoses at D.P.F. EGR sensor.
Connect a hand vacuum pump to the downstream connection at sensor (intake manifold side of sensor or the smaller diameter pickup tube.)
Key ON, Engine OFF.
Access DPFEGR PID and note PID value.
Apply 27-30 kPa (8-9 in-Hg) vacuum to the D.P.F. EGR sensor and hold for 5 seconds.
Quickly release vacuum.
The DPFEGR PID voltage must be between 0.2V and 1.3V DC with the key ON and no vacuum applied.
The DPFEGR PID voltage must increase to greater than 4.0V DC with the vacuum applied.
The DPFEGR PID must drop to less than 1.5V DC in less than 3 seconds when vacuum is released.
Does the DPFEGR PID voltage indicate a fault in the D.P.F. EGR sensor?
Yes No
REPLACE D.P.F. EGR sensor. RECONNECT pressure hoses. GO to HE93 .

HE93 CHECK EGR VALVE FUNCTION BY APPLYING VACUUM WITH HAND PUMP
Disconnect vacuum hose at EGR valve and plug hose.
Connect a hand vacuum pump to EGR valve.
Start engine.
Access DPFEGR and RPM PIDs.
Slowly apply 17 to 34 kPa (5 to 10 in-Hg) of vacuum to the EGR valve and hold it for 10 seconds. If engine wants to stall, increase rpm with throttle to maintain a minimum of 800 RPM.
Look for the following:
EGR valve starts opening at about 5.4 kPa (1.6 in-Hg) vacuum indicated by increasing DPFEGR PID voltage.
DPFEGR PID voltage increasing until EGR valve is fully open. DPFEGR PID should read 2.5V DC minimum with full vacuum applied.
DPFEGR PID voltage steady when vacuum is held. If voltage drops within 5 seconds, the EGR valve or vacuum source could be leaking.
Does the DPFEGR PID voltage indicate that the EGR valve is operating as described in this test?
Yes No
GO to HE94 . REMOVE and INSPECT the EGR valve for signs of contamination, unusual wear, carbon deposits, binding, leaking diaphragm and other damage. If EGR valve is OK, look for an obstructed EGR port in the intake manifold. REPAIR as necessary.

HE94 INSPECT EGR VACUUM SIGNAL SUPPLY FOR INTERMITTENT FAILURE
Disconnect plugged hose at EGR valve and connect to a vacuum gauge.
Key ON, Engine RUNNING.
Connect a jumper wire between EGRVR circuit and ground to activate the solenoid to full ON. At idle, the vacuum gauge should read above 13.5 kPa (4.0 in-Hg).
Observe vacuum gauge for an indication of a fault while performing the following:
Lightly tap on the EGR vacuum regulator solenoid and wiggle the EGR vacuum regulator solenoid connector, vacuum lines and vehicle harness between the solenoid and PCM. A fault is indicated by a sudden drop in vacuum reading.
Is a fault indicated?
Yes No
ISOLATE fault and REPAIR as necessary. Unable to duplicate or identify fault at this time. (In cold climates, the EGR valve may temporarily freeze shut and thaw when the engine warms up causing the intermittent DTC.) GO to Z1 .

HE100 EGR DIAGNOSIS BY SYMPTOM: CHECK FOR EGR FLOW WITH EGR VACUUM HOSE DISCONNECTED AND PLUGGED
Note: Perform KOER Self-Test and repair any DTCs before proceeding with this test.

The symptom charts indicate possible EGR flow at idle with no EGR diagnostic trouble codes present.

Possible causes:

EGR valve not fully seating.
EGR vacuum regulator solenoid vent restricted.
Damaged EGR vacuum regulator solenoid.
Disconnect vacuum hose at EGR valve and plug hose.
Key ON, Engine OFF.
Access DPFEGR PID and note voltage.
Start engine.
With engine at idle, look at the DPFEGR PID voltage and compare to the engine OFF reading. An increase in the voltage at idle indicates that the differential pressure feedback EGR sensor is sensing EGR flow.
Is the DPFEGR PID voltage greater at idle by a minimum of 0.15V DC than with the engine OFF?
Yes No
The DPFEGR PID voltage is indicating EGR flow at idle. Since the EGR vacuum hose is disconnected and plugged, the fault is most likely in the EGR valve. REMOVE and INSPECT the EGR valve for signs of contamination, unusual wear, carbon deposits, binding and other damage. REPAIR as necessary. This indicates a fault in the EGR valve vacuum supply. INSPECT the EGR vacuum regulator solenoid vent and vent filter for restrictions. REPAIR as necessary. If OK, REPLACE EGR vacuum regulator solenoid.

HE110 DTC P0403, P1409: CHECK EGR VACUUM REGULATOR SOLENOID RESISTANCE
Disconnect EGR vacuum regulator solenoid.
Measure EGR vacuum regulator solenoid resistance.
Is solenoid resistance between 26 and 40 ohms?
Yes No
GO to HE111 . REPLACE EGR vacuum regulator solenoid.

HE111 CHECK VPWR VOLTAGE TO EGR VACUUM REGULATOR SOLENOID
Key ON, Engine OFF.
Measure VPWR circuit voltage at EGR vacuum regulator solenoid harness connector.
Is voltage greater than 10.5V DC?
Yes No
Key OFF. GO to HE112 . REPAIR open in VPWR circuit.

HE112 CHECK EGRVR CIRCUIT FOR OPEN IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Disconnect PCM.
Measure resistance of EGRVR circuit between PCM Pin and EGR vacuum regulator solenoid harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to HE113 . REPAIR open in EGRVR circuit.

HE113 CHECK EGRVR CIRCUIT FOR SHORT TO POWER IN HARNESS
Key ON, Engine OFF.
Measure voltage between EGRVR at the PCM harness connector and battery (-) terminal.
Is voltage less than 1.0V DC?
Yes No
Key OFF. GO to HE114 . REPAIR short circuit.

HE114 CHECK EGRVR CIRCUIT FOR SHORT TO GROUND IN HARNESS
Measure resistance between EGRVR and PWR GND circuits at the PCM harness connector.
Is each resistance greater than 10K ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.

HE120 CONTINUOUS MEMORY DTC P0403, P1409: WIGGLE EGR VACUUM REGULATOR SOLENOID WHILE MONITORING VPWR
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.

Note: If DTC P1409 appeared after running Key On Engine Off (KOEO) or Key On Engine Running (KOER) Self-Test, GO to HE110 to diagnose present fault.

Disconnect PCM.
Key ON.
Measure voltage between EGRVR and PWR GND circuits at the PCM harness connector.
Voltage must read greater than 10.5V DC. For an indication of a fault, look for this voltage to drop while performing the following:
Lightly tap on the EGR vacuum regulator solenoid.
Wiggle the EGR vacuum regulator solenoid connector.
Grasp the EGR vacuum regulator solenoid harness connector and wiggle wires between solenoid and PCM.
Is a fault indicated?
Yes No
ISOLATE fault and REPAIR as necessary. Unable to duplicate or identify fault at this time. GO to Z1 .




--------------------------------------------------------------------------------

 

[hotcobra03]

 

[Boogie Chillin]

Well that's a bit different from unofficial instructions I found for testing the DPFE. I'll check the wire harness, I can order another one of those if it changes by moving it around. I wonder if the code resets if the voltage goes up to the .2 V range. Thanks for looking that up. Here is what I found on the net - looks like that is wrong.


How to troubleshoot Ford EGR
Step 1) Check the condition of the vacuum hoses going to the DPFE sensor and the EVR. Look for cracks or tears. Replace the hose if you find any.
Step 2) Check the operation of the DPFE with the engine off, key in the run position. Using a digital voltmeter, check for voltage on the brown/light green wire. Look for a reading between .45 and 1.1 volts. If your reading is outside that range, you have one more voltage check to perform before replacing the sensor. Check the voltage on the brown/white wire. It should read 5 volts. If it doesn’t, the sensor isn’t getting power from the computer. Then it’s a whole new ballgame. If you have 5 volts, and the reading from the brown/light green wire is outside the range, replace the DPFE. After replacement, perform the voltage check again to eliminate the possibility that the EGR valve is not seating properly.
Step 3) Leave your meter connected and start the engine. The voltage SHOULD NOT CHANGE! That’s because there should be no EGR flow at idle. If the DPFE voltage changes, either the EGR pintle isn’t seating properly and it’s allowing exhaust flow past the seat, or the DPFE is bad.
Step 4) Remove the EGR valve and check the condition of the pintle, pintle seat, and the EGR passages. They will be coated with black soot. But the passages should not be clogged and the pintle should move off its seat with the application of vacuum. Clean
the pintle, pintle seat, and passages with carb or throttle body cleaner.

 

[hotcobra03]

the full pc version of service manual.

found in stickys..it's a must have..

 

[Boogie Chillin]

So, according to the Manual's Voltage Reference Table the DPFEGR at KOEO and Idle should be 0.95-1.05 V. It looks like I have a high voltage / not low on both DPFE sensors when the engine is on.

New DPFE Connected:

KOEO -
DPFE Brown/Green 1.016 V SIG

EO -
DPFE Brown/Green EO [IDLE ~800ish rpm]- 1.091-1.186 V

Old DPFE Connected:

KOEO -
DPFE Brown/Green 1.030 V SIG

EO -
DPFE Brown/Green EO [IDLE ~800ish rpm] SIG
1.103-1.199V
AVG: 1.136V

 

[Boogie Chillin]

If the DTC codes are cleared with a tuner, is the PCM also cleared? Or does the battery need to be disconnected for 15 minutes do a complete reset?

 

[hotcobra03]

If the DTC codes are cleared with a tuner, is the PCM also cleared? Or does the battery need to be disconnected for 15 minutes do a complete reset?

yes.clearing codes with scanner is like dis connecting battery.

you will need to complete a drivecycle.

 

[Boogie Chillin]

Well, I ordered another DPFE, used, as a last resort. I have followed the Shop Manual to the point of resistance checking the wires back to the PCM. I don't have advanced OBDII tools to pull any diagnostic data.

I'm at a loss. I can only guess has to be either two bad DPFEs, tune, or bad PCM.

 

[hotcobra03]

what shape are the hoses in.

there is another recent thread on this sensor..he is having issues with hoses blowing off..

these are special hoses..blocked hose? cracked but still on..

are they off and plugged?but loom like they go down back of head.

 

[Boogie Chillin]

Hoses are good. At idle, EGR remains closed, so the VREF shouldn’t change from KOEO to idle.

Mine fluctuates between 1.03-1.17 with the AC off and up to 1.27 with it on. That is the same with the hoses on or off and plugged. So the delta between the hoses can’t be causing it.


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