Can anyone help me out on what this code means?
"P0123"
"Throttle/Pedal Position Sensor A Circuit High Input."
Thanks much
"P0123"
"Throttle/Pedal Position Sensor A Circuit High Input."
Thanks much
engine code P0123?
- Thread starter MaximusDecimus
- Start date
Awesome... nobody knows.
Sounds like your TPS sensor is bad.
Go to www.google.com and type in site:svtperformance.com "P0123"
These cars have been around just over 10 years and people have posted their issues with these cars plenty of times on this website.. simple search will show the problem and solution others found
Any issue you may have with your terminator you're almost guaranteed some body some where on this site has had the exact same issue and posted about it
These cars have been around just over 10 years and people have posted their issues with these cars plenty of times on this website.. simple search will show the problem and solution others found
Any issue you may have with your terminator you're almost guaranteed some body some where on this site has had the exact same issue and posted about it
Last edited:
Just put a brand new tps on and same code is thrown.... is there a separate gas pedal sensor somewhere??
what typr of throttlebody is being used?
you need to test ..not replace...
P0123 - Throttle Position (TP) Circuit High Input The TP sensor circuit is monitored by the PCM for a high TP rotation angle (or voltage) input through the comprehensive component monitor (CCM). If during key ON engine OFF or key ON engine running the TP rotation angle (or voltage) changes above maximum calibrated limit, the test fails. TP sensor not seated properly
TP circuit short to PWR
TP circuit short to ETCREF
SIG RTN circuit open to TP sensor
Damaged TP sensor
Damaged PCM
A TP PID (TP V PID) reading greater than 93% (4.65 volts) in key ON engine OFF, continuous memory or key ON engine running indicates a hard fault.
your code po123 start at dh8
2003 PCED OBD SECTION 5: Pinpoint Tests
Procedure revision date: 08/19/2002
--------------------------------------------------------------------------------
DH: Throttle Position (TP) Sensor DH: Introduction
--------------------------------------------------------------------------------
DH1 KOEO AND KOER DTC P1124: CHECK FOR OTHER DTCS
Check for DTC P1400 or P0405 in KOEO or KOER Self-Test.
Is KOEO or KOER DTC P1400 or P0405 present with KOEO DTC P1124?
Yes No
RETURN to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts for DTC P1400 or P0405. KEY OFF. GO to DH2 .
DH2 CHECK FOR STUCK THROTTLE PLATE OR LINKAGE
Visually inspect the throttle linkage and throttle plate for binding or sticking.
Verify the throttle plate and linkage is at closed throttle position.
Does the throttle move freely and return to closed throttle position?
Yes No
Throttle plate and linkage are OK. GO to DH8 . REPAIR as necessary.
DH3 DTC P1120: CHECK TP CIRCUIT FOR FRAYED WIRES OR CORROSION ON CONNECTORS
Key off.
Complete a visual inspection of pins on harness connector at the TP sensor for corrosion.
Complete a visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.
Is a fault present?
Yes No
REPAIR as necessary. GO to DH4 .
DH4 CHECK FOR STUCK TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position and observe the TP PID (TP V PID).
While opening the throttle, is the TP PID (TPV PID) reading below 9.85% (0.49 volt)?
Yes No
KEY OFF. GO to DH5 . GO to DH20 .
DH5 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS TO TP SENSOR
Disconnect TP sensor.
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH6 . GO to C1 .
DH6 CHECK TP 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 TP circuit between PCM harness connector pin and TP harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH7 . REPAIR open circuit.
DH7 CHECK TP SENSOR VOLTAGE TO PCM
Reconnect PCM and TP sensor.
Start engine and idle for 2 minutes.
Access TP PID (TP V PID).
Slowly open the throttle from closed position and observe PID(s).
Is TP PID (TP V PID) reading at any time between 3.42-9.85% (0.17-0.49 volt)?
Yes No
REPLACE TP sensor. If DTC P1120 is still present, GO to DH20 .
DH8 DTC P0123 OR P1124: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Disconnect TP sensor.
Key on, engine off.
Access TP PID (TP V PID).
Is TP PID (TP V PID) less than 3.42% (0.17 volt)?
Yes No
GO to DH9 . KEY OFF. GO to DH10 .
DH9 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS AT TP SENSOR
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
REPLACE TP sensor. GO to C1 .
DH10 CHECK TP CIRCUIT FOR SHORT TO VREF OR VPWR IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
Disconnect PCM.
Measure resistance between TP and VPWR circuits at the PCM harness connector.
Measure resistance between TP and VREF circuits at the PCM harness connector. (For 150 PIN PCM and 122 PCM PIN, measure to both VREF pins.)
Is each resistance greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.
DH11 DTC P0122: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Note: An intermittent fault can cause a Continuous Memory DTC P0122. If a Continuous Memory DTC P0122 is still present after DH11 through DH14, GO to Z1 .
Disconnect TP sensor.
Jumper VREF circuit to TP circuit at the TP sensor harness connector.
Key on, engine off.
Note: If any scan tool communication concern exists, remove jumper and GO to DH14 .
Access TP PID (TP V PID).
Is TP PID (TP V PID) greater than 93% (4.65 volts)?
Yes No
REPLACE TP sensor. REMOVE jumper. GO to DH12 .
DH12 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH13 . GO to C1 .
DH13 CHECK TP SENSOR 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 TP circuit between PCM harness connector pin and TP sensor harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH14 . REPAIR open circuit.
DH14 CHECK TP CIRCUIT FOR SHORT TO PWR GND OR SIG RTN IN HARNESS
Disconnect PCM.
Disconnect scan tool from DLC.
Measure resistance between TP and PWR GND circuits at the PCM harness connector.
Measure resistance between TP and SIG RTN circuits at the PCM harness connector.
Are both resistances greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.
DH15 DTC P1121 OR P0068: CHECK RATIONALITY OPERATION BETWEEN TP AND MAF SENSORS
Attempt to start engine.
Does the engine run?
Yes No
GO to DH16 . CHECK for major leaks, cracks, and openings between MAF sensor and throttle body. If OK, GO to A1 .
DH16 CHECK MECHANICAL OPERATION OF TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position.
Observe and record the TP PID (TP V PID).
While opening and closing the throttle, is there a change in the TP PID (TP V PID) between 9.85% and 93% (0.49 and 4.65 volts)?
Yes No
GO to DH17 . REPLACE TP sensor. VERIFY a symptom no longer exists.
DH17 CHECK TP SENSOR SIGNAL HIGH VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Key on, engine running.
Drive vehicle, exercising the throttle and TP sensor while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID and record readings.
Is TP PID (TP V PID) greater than 49.02% (2.44 volts) and the LOAD PID reading less than 30%?
Yes No
LISTEN for air noise around MAF sensor and throttle body while engine is running. REPAIR if necessary. Otherwise, GO to HU1 for air restriction. If OK, REPLACE the TP sensor. GO to DH18 .
DH18 CHECK TP SENSOR SIGNAL LOW VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Note: If the vehicle is a no start, GO to A1 .
Drive vehicle exercising the throttle and TP sensor near higher gears (preferably overdrive) while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID.
Is TP PID (TP V PID) reading less than 4.82% (0.24 volts) and the LOAD PID reading greater than 55%?
Yes No
TIGHTEN TP sensor to throttle body if necessary. CLEAR Continuous Memory DTCs. DRIVE vehicle exercising the throttle. If Continuous Memory P1121 is now present, REPLACE MAF sensor. Unable to identify the fault at this time. If vehicle is still a No Start, GO to A1 .
DH20 CONTINUOUS MEMORY DTCS P1120 OR P1125: CHECK FOR TP CIRCUIT INTERMITTENT SIGNAL
Start engine and bring to idle.
Run throttle up to 1500 rpm for 5 seconds.
Access TP PID (TP V PID) for a fault indication while completing the following:
Lightly tap on TP sensor and wiggle harness connector to simulate road shock.
Is TP PID (TP V PID) changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
INSPECT the TP sensor connector. If OK, REPLACE the TP sensor. KEY OFF. GO to DH21 .
DH21 CHECK TP SENSOR HARNESS FOR INTERMITTENT OPENS OR SHORTS
Again access the TP PID (TP V PID).
Key on, engine off.
Complete the following:
Grasp the vehicle harness closest to the TP sensor connector.
Shake and bend a small section of the harness all the way to the dash panel.
Wiggle, shake and bend the harness from the dash panel to the PCM.
Is TP PID (TP V PID) reading changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
ISOLATE and REPAIR as necessary. Unable to duplicate or identify fault at this time.GO to Z1
DH22 DTC P0121: ISOLATE BINDING OR STICKING CONCERN
Disconnect accelerator cable and speed control cable from throttle body linkage.
CAUTION: Do not attempt to clean the throttle bore and plate area. Cleaning will damage the throttle body assembly.
Note: Sticking or binding condition can either appear within cables or throttle body assembly.
Rotate throttle body linkage.
Does the throttle body rotate freely without a sticking, binding or grabbing condition?
Yes No
INSPECT cable(s). REPAIR as necessary. RERUN Quick Test. If the DTC P0121 is still present, GO to DH23 . REPLACE throttle body assembly.
DH23 CHECK FUNCTIONALITY OF THE THROTTLE POSITION SENSOR
Key on.
Access TP V PID.
From closed throttle, slowly begin to press accelerator to wide open throttle.
Did the TP V PID display a smooth reading during accelerator movement?
Yes No
VERIFY a symptom no longer exists. KEY OFF. REPLACE TP sensor.
--------------------------------------------------------------------------------
you need to test ..not replace...
P0123 - Throttle Position (TP) Circuit High Input The TP sensor circuit is monitored by the PCM for a high TP rotation angle (or voltage) input through the comprehensive component monitor (CCM). If during key ON engine OFF or key ON engine running the TP rotation angle (or voltage) changes above maximum calibrated limit, the test fails. TP sensor not seated properly
TP circuit short to PWR
TP circuit short to ETCREF
SIG RTN circuit open to TP sensor
Damaged TP sensor
Damaged PCM
A TP PID (TP V PID) reading greater than 93% (4.65 volts) in key ON engine OFF, continuous memory or key ON engine running indicates a hard fault.
your code po123 start at dh8
2003 PCED OBD SECTION 5: Pinpoint Tests
Procedure revision date: 08/19/2002
--------------------------------------------------------------------------------
DH: Throttle Position (TP) Sensor DH: Introduction
--------------------------------------------------------------------------------
DH1 KOEO AND KOER DTC P1124: CHECK FOR OTHER DTCS
Check for DTC P1400 or P0405 in KOEO or KOER Self-Test.
Is KOEO or KOER DTC P1400 or P0405 present with KOEO DTC P1124?
Yes No
RETURN to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts for DTC P1400 or P0405. KEY OFF. GO to DH2 .
DH2 CHECK FOR STUCK THROTTLE PLATE OR LINKAGE
Visually inspect the throttle linkage and throttle plate for binding or sticking.
Verify the throttle plate and linkage is at closed throttle position.
Does the throttle move freely and return to closed throttle position?
Yes No
Throttle plate and linkage are OK. GO to DH8 . REPAIR as necessary.
DH3 DTC P1120: CHECK TP CIRCUIT FOR FRAYED WIRES OR CORROSION ON CONNECTORS
Key off.
Complete a visual inspection of pins on harness connector at the TP sensor for corrosion.
Complete a visual inspection of the harness wires between the TP sensor and the PCM for insulation fraying and corrosion.
Is a fault present?
Yes No
REPAIR as necessary. GO to DH4 .
DH4 CHECK FOR STUCK TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position and observe the TP PID (TP V PID).
While opening the throttle, is the TP PID (TPV PID) reading below 9.85% (0.49 volt)?
Yes No
KEY OFF. GO to DH5 . GO to DH20 .
DH5 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS TO TP SENSOR
Disconnect TP sensor.
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH6 . GO to C1 .
DH6 CHECK TP 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 TP circuit between PCM harness connector pin and TP harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH7 . REPAIR open circuit.
DH7 CHECK TP SENSOR VOLTAGE TO PCM
Reconnect PCM and TP sensor.
Start engine and idle for 2 minutes.
Access TP PID (TP V PID).
Slowly open the throttle from closed position and observe PID(s).
Is TP PID (TP V PID) reading at any time between 3.42-9.85% (0.17-0.49 volt)?
Yes No
REPLACE TP sensor. If DTC P1120 is still present, GO to DH20 .
DH8 DTC P0123 OR P1124: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Disconnect TP sensor.
Key on, engine off.
Access TP PID (TP V PID).
Is TP PID (TP V PID) less than 3.42% (0.17 volt)?
Yes No
GO to DH9 . KEY OFF. GO to DH10 .
DH9 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS AT TP SENSOR
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
REPLACE TP sensor. GO to C1 .
DH10 CHECK TP CIRCUIT FOR SHORT TO VREF OR VPWR IN HARNESS
Note: Refer to the PCM connector pin numbers in the beginning of this pinpoint test.
Disconnect PCM.
Measure resistance between TP and VPWR circuits at the PCM harness connector.
Measure resistance between TP and VREF circuits at the PCM harness connector. (For 150 PIN PCM and 122 PCM PIN, measure to both VREF pins.)
Is each resistance greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.
DH11 DTC P0122: ATTEMPT TO GENERATE THE OPPOSITE THROTTLE POSITION ANGLE (VOLTAGE) PID READING
Note: An intermittent fault can cause a Continuous Memory DTC P0122. If a Continuous Memory DTC P0122 is still present after DH11 through DH14, GO to Z1 .
Disconnect TP sensor.
Jumper VREF circuit to TP circuit at the TP sensor harness connector.
Key on, engine off.
Note: If any scan tool communication concern exists, remove jumper and GO to DH14 .
Access TP PID (TP V PID).
Is TP PID (TP V PID) greater than 93% (4.65 volts)?
Yes No
REPLACE TP sensor. REMOVE jumper. GO to DH12 .
DH12 CHECK VOLTAGE BETWEEN VREF AND SIG RTN CIRCUITS
Key on, engine off.
Measure voltage between VREF and SIG RTN circuits at the TP sensor harness connector.
Is voltage between 4.0 and 6.0 volts?
Yes No
KEY OFF. GO to DH13 . GO to C1 .
DH13 CHECK TP SENSOR 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 TP circuit between PCM harness connector pin and TP sensor harness connector.
Is resistance less than 5.0 ohms?
Yes No
GO to DH14 . REPAIR open circuit.
DH14 CHECK TP CIRCUIT FOR SHORT TO PWR GND OR SIG RTN IN HARNESS
Disconnect PCM.
Disconnect scan tool from DLC.
Measure resistance between TP and PWR GND circuits at the PCM harness connector.
Measure resistance between TP and SIG RTN circuits at the PCM harness connector.
Are both resistances greater than 10,000 ohms?
Yes No
REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) ). REPAIR short circuit.
DH15 DTC P1121 OR P0068: CHECK RATIONALITY OPERATION BETWEEN TP AND MAF SENSORS
Attempt to start engine.
Does the engine run?
Yes No
GO to DH16 . CHECK for major leaks, cracks, and openings between MAF sensor and throttle body. If OK, GO to A1 .
DH16 CHECK MECHANICAL OPERATION OF TP SENSOR
Key on, engine off.
Access TP PID (TP V PID).
Slowly move throttle from closed throttle position to wide open throttle position.
Observe and record the TP PID (TP V PID).
While opening and closing the throttle, is there a change in the TP PID (TP V PID) between 9.85% and 93% (0.49 and 4.65 volts)?
Yes No
GO to DH17 . REPLACE TP sensor. VERIFY a symptom no longer exists.
DH17 CHECK TP SENSOR SIGNAL HIGH VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Key on, engine running.
Drive vehicle, exercising the throttle and TP sensor while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID and record readings.
Is TP PID (TP V PID) greater than 49.02% (2.44 volts) and the LOAD PID reading less than 30%?
Yes No
LISTEN for air noise around MAF sensor and throttle body while engine is running. REPAIR if necessary. Otherwise, GO to HU1 for air restriction. If OK, REPLACE the TP sensor. GO to DH18 .
DH18 CHECK TP SENSOR SIGNAL LOW VERSUS THE ENGINE LOAD WHILE DRIVING VEHICLE
Note: If the vehicle is a no start, GO to A1 .
Drive vehicle exercising the throttle and TP sensor near higher gears (preferably overdrive) while accessing PIDS.
Access TP PID (TP V PID) and LOAD PID.
Is TP PID (TP V PID) reading less than 4.82% (0.24 volts) and the LOAD PID reading greater than 55%?
Yes No
TIGHTEN TP sensor to throttle body if necessary. CLEAR Continuous Memory DTCs. DRIVE vehicle exercising the throttle. If Continuous Memory P1121 is now present, REPLACE MAF sensor. Unable to identify the fault at this time. If vehicle is still a No Start, GO to A1 .
DH20 CONTINUOUS MEMORY DTCS P1120 OR P1125: CHECK FOR TP CIRCUIT INTERMITTENT SIGNAL
Start engine and bring to idle.
Run throttle up to 1500 rpm for 5 seconds.
Access TP PID (TP V PID) for a fault indication while completing the following:
Lightly tap on TP sensor and wiggle harness connector to simulate road shock.
Is TP PID (TP V PID) changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
INSPECT the TP sensor connector. If OK, REPLACE the TP sensor. KEY OFF. GO to DH21 .
DH21 CHECK TP SENSOR HARNESS FOR INTERMITTENT OPENS OR SHORTS
Again access the TP PID (TP V PID).
Key on, engine off.
Complete the following:
Grasp the vehicle harness closest to the TP sensor connector.
Shake and bend a small section of the harness all the way to the dash panel.
Wiggle, shake and bend the harness from the dash panel to the PCM.
Is TP PID (TP V PID) reading changing below the minimum 9.85% (0.49 volt) or above the maximum 93% (4.65 volts)?
Yes No
ISOLATE and REPAIR as necessary. Unable to duplicate or identify fault at this time.GO to Z1
DH22 DTC P0121: ISOLATE BINDING OR STICKING CONCERN
Disconnect accelerator cable and speed control cable from throttle body linkage.
CAUTION: Do not attempt to clean the throttle bore and plate area. Cleaning will damage the throttle body assembly.
Note: Sticking or binding condition can either appear within cables or throttle body assembly.
Rotate throttle body linkage.
Does the throttle body rotate freely without a sticking, binding or grabbing condition?
Yes No
INSPECT cable(s). REPAIR as necessary. RERUN Quick Test. If the DTC P0121 is still present, GO to DH23 . REPLACE throttle body assembly.
DH23 CHECK FUNCTIONALITY OF THE THROTTLE POSITION SENSOR
Key on.
Access TP V PID.
From closed throttle, slowly begin to press accelerator to wide open throttle.
Did the TP V PID display a smooth reading during accelerator movement?
Yes No
VERIFY a symptom no longer exists. KEY OFF. REPLACE TP sensor.
--------------------------------------------------------------------------------
a handheld tuner might work for testing..you will need multi meter
i had a stock tb go bad....it had a sticking or binding shaft issues...i still have it..i use it for testing...
i had a stock tb go bad....it had a sticking or binding shaft issues...i still have it..i use it for testing...
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