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SN95 Cobras
1997 mustang cobra problem please help
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<blockquote data-quote="hotcobra03" data-source="post: 16279843" data-attributes="member: 53096"><p><a href="https://app-na.readspeaker.com/cgi-bin/rsent?customerid=7827&lang=en_us&readid=dvRSContent&url=www.chiltonlibrary.com%2fRepair%2fReadArticleContent%2fmwellVaSq2DTHaW4SQe_LWG9rOvUVyU3ErXhmpuMCr92xjbQ1%7c176550%7c44549" target="_blank">Listen</a></p><p><span style="font-size: 22px"><strong>HD: Misfire Detection Monitor</strong></span></p><p></p><p>1997 PCED On Board Diagnostics II A</p><p></p><p> </p><p>SECTION 5A: Pinpoint Tests</p><p></p><p> </p><p>HD: Misfire Detection Monitor</p><p></p><p> ← HD: Introduction</p><p><strong>HD1 CHECK POSSIBLE CAUSES OF MISFIRE</strong></p><p></p><p></p><p>NOTE</p><p>Note: Running out of fuel can turn on the MIL and possibly store a Continuous Misfire DTC.</p><p></p><p></p><p></p><p>Misfire Continuous Memory Diagnostic Trouble Codes (DTCs):</p><p></p><ul> <li data-xf-list-type="ul">P0301 - Cyl No.1, Fuel Inj. Test Pin 75<br /> <br /> </li> <li data-xf-list-type="ul">P0302 - Cyl No.2, Fuel Inj. Test Pin 101<br /> <br /> </li> <li data-xf-list-type="ul">P0303 - Cyl No.3, Fuel Inj. Test Pin 74<br /> <br /> </li> <li data-xf-list-type="ul">P0304 - Cyl No.4, Fuel Inj. Test Pin 100<br /> <br /> </li> <li data-xf-list-type="ul">P0305 - Cyl No.5, Fuel Inj. Test Pin 73<br /> <br /> </li> <li data-xf-list-type="ul">P0306 - Cyl No.6, Fuel Inj. Test Pin 99<br /> <br /> </li> <li data-xf-list-type="ul">P0307 - Cyl No.7, Fuel Inj. Test Pin 72<br /> <br /> </li> <li data-xf-list-type="ul">P0308 - Cyl No.8, Fuel Inj. Test Pin 98<br /> <br /> </li> <li data-xf-list-type="ul">P0309 - Cyl No.9, Fuel Inj. Test Pin 68<br /> <br /> </li> <li data-xf-list-type="ul">P0310 - Cyl No.10, Fuel Inj. Test Pin 42<br /> </li> </ul><p>Possible causes:</p><p></p><ul> <li data-xf-list-type="ul">Ignition System.<br /> <br /> </li> <li data-xf-list-type="ul">Fuel Injectors.<br /> <br /> </li> <li data-xf-list-type="ul">Fuel Pressure.<br /> <br /> </li> <li data-xf-list-type="ul">Evaporative Emission System.<br /> <br /> </li> <li data-xf-list-type="ul">EVAP Canister Purge Valve.<br /> <br /> </li> <li data-xf-list-type="ul">Base Engine.<br /> <br /> </li> <li data-xf-list-type="ul">Running out of fuel.<br /> </li> </ul><p>Has the vehicle recently run out of fuel?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>OBD II system OK. COMPLETE PCM Reset to clear DTCs. RETURN vehicle to customer. GO to HD2.</p><p><strong>HD2 CHECK DAMPER AND PULLEY ASSEMBLY</strong></p><ul> <li data-xf-list-type="ul"><br /> All others:CAUTION: Remove the front cover if necessary to observe the crank pulley.</li> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Observe the crank pulley for wobble.<br /> <br /> </li> <li data-xf-list-type="ul">Examine the EI pulse ring fastened to the harmonic fastener.<br /> </li> </ul><p>Does the crank pulley wobble or is the pulse ring loose or damaged?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>REPLACE the pulley or damper assembly. RERUN Quick Test. GO to HD3.</p><p><strong>HD3 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS</strong></p><p></p><p></p><p>NOTE</p><p>Note: Check for other non-misfire Continuous Memory DTCs which could cause the misfire DTC.</p><p></p><p></p><p></p><p>Possible causes:</p><p></p><ul> <li data-xf-list-type="ul">Camshaft Position (CMP) Sensor.<br /> <br /> </li> <li data-xf-list-type="ul">Octane Adjust (OCT ADJ).<br /> <br /> </li> <li data-xf-list-type="ul">Ignition Coil Primary Circuit.<br /> <br /> </li> <li data-xf-list-type="ul">Knock Sensor (KS).<br /> </li> </ul><p>Are other non-misfire Continuous Memory DTCs present?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>ADDRESS the next Continuous Memory DTC. DISREGARD Misfire DTC at this time. Go to Section 4A for Powertrain DTC Charts. GO to HD4.</p><p><strong>HD4 CHECK FOR ON-DEMAND SELF-TEST DTCS</strong></p><p></p><p></p><p>NOTE</p><p>Note: Check for any key on, engine off DTCs which could cause the Misfire DTC.</p><p></p><p></p><p></p><p>Are any key on, engine off DTCs displayed on the Scan Tool?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Go to Section 4A, Powertrain DTC Charts, and PROCEED as required.</p><p>Coil On Plug applications:</p><p></p><p>GO to Pinpoint Test Step JF1.</p><p></p><p>All others:</p><p></p><p>GO to JB1 to evaluate spark plugs and secondary wires. If OK, GO to HD5.</p><p><strong>HD5 CHECK FOR OTHER KEY ON ENGINE RUNNING DTCS</strong></p><p></p><p></p><p>NOTE</p><p>Note: Check for any other key on, engine running DTCs which can cause the Misfire DTC.</p><p></p><p></p><p></p><p>Are any additional key on, engine running DTCs displayed on the Scan Tool?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>If DTCs P1131, P1137, P1151 or P1157 are present, GO to HD8.</p><p></p><p>All others: Go to Section 4A, Powertrain DTC Charts, and PROCEED as required.</p><p>Vehicles with D.P.F. EGR Systems: GO to HD6.</p><p></p><p>All others: GO to HD8.</p><p><strong>HD6 CHECK/COMPARE PID VALUES</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Connect Scan Tool.<br /> <br /> </li> <li data-xf-list-type="ul">Accessories off (A/C, heater, etc.).<br /> <br /> </li> <li data-xf-list-type="ul">Start engine and warm to normal operating temperature.<br /> <br /> </li> <li data-xf-list-type="ul">Access DPFEGR PID with the Scan Tool.<br /> <br /> </li> <li data-xf-list-type="ul">Key on, engine off.<br /> <br /> </li> <li data-xf-list-type="ul">Record DPFEGR PID value.<br /> <br /> </li> <li data-xf-list-type="ul">Start engine, let idle.<br /> <br /> </li> <li data-xf-list-type="ul">Compare key on, engine off and engine running PID values.<br /> </li> </ul><p>Was engine running PID value within 0.15 volt of key on, engine off value?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Disconnect Scan Tool. GO to HD8. GO to Pinpoint Test Step HE100.</p><p><strong>HD8 CHECK RESISTANCE OF FUEL INJECTOR(S) AND HARNESS</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Disconnect PCM. Inspect for damaged or pushed out pins, corrosion and loose wires. Service as necessary.<br /> <br /> </li> <li data-xf-list-type="ul">Install breakout box, leave PCM disconnected.<br /> <br /> </li> <li data-xf-list-type="ul">Measure resistance between suspect fuel injector test pin and Test Pin 71 or 97 at the breakout box. Refer to the list in HD1.<br /> </li> </ul><p>Is the resistance between 11.0-18.0 ohms?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Fuel injector and harness resistance is OK. GO to HD9. GO to Pinpoint Test Step H56 to diagnose fuel injectors.</p><p><strong>HD9 CHECK INJECTOR DRIVER SIGNAL</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Breakout box installed.<br /> <br /> </li> <li data-xf-list-type="ul">Connect PCM to breakout box.<br /> <br /> </li> <li data-xf-list-type="ul">Connect Test Lamp between Test Pin 71 or 97 and suspect injector test pin.<br /> <br /> </li> <li data-xf-list-type="ul">Start engine.<br /> </li> </ul><p>Does test lamp have a dim glow while running engine?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD10. No light or bright light: REPLACE PCM. REMOVE breakout box. RERUN Quick Test.</p><p><strong>HD10 CHECK FUEL PRESSURE</strong></p><ul> <li data-xf-list-type="ul"><br /> WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHILE WORKING ON THE FUEL SYSTEM.</li> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Install fuel pressure gauge.<br /> <br /> </li> <li data-xf-list-type="ul">Start and run engine at idle. Record fuel pressure.<br /> <br /> </li> <li data-xf-list-type="ul">Increase engine speed to 2500 rpm and maintain for one minute. Note and compare fuel pressure.<br /> </li> </ul><p>Is fuel pressure between 210-310 kPa (30-45 psi)?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD11. GO to Powertrain/Fuel System Group in the Service Manual.</p><p><strong>HD11 CHECK ABILITY OF FUEL SYSTEM TO HOLD FUEL PRESSURE</strong></p><ul> <li data-xf-list-type="ul">Start and run engine at idle. Note fuel pressure.<br /> <br /> </li> <li data-xf-list-type="ul">Increase engine speed to 2500 rpm and maintain for one minute.<br /> <br /> </li> <li data-xf-list-type="ul">Look for fuel leaking at the fuel injector O-ring, fuel pressure regulator and the fuel lines to the fuel charging assembly. Service as necessary.<br /> <br /> </li> <li data-xf-list-type="ul">Turn engine off.<br /> <br /> </li> <li data-xf-list-type="ul">Key on, engine off.<br /> </li> </ul><p>Does fuel pressure remain at specification within 16.5 kPa (5 psi) for 60 seconds?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD12. GO to Powertrain/Engine or Fuel System Group in the Service Manual to determine which area within the Fuel Delivery System is at fault.</p><p><strong>HD12 CHECK FUEL INJECTOR FOR FLOW AND LEAKAGE</strong></p><ul> <li data-xf-list-type="ul">Refer to Warning, Caution and Handling at the beginning of Pinpoint Test HC to avoid fuel spillage and injury.<br /> <br /> </li> <li data-xf-list-type="ul">Verify that the flow rate for each fuel injector is within specification using Injector Flow Tester.<br /> </li> </ul><p>Is flow rate for each fuel injector within specification?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Fuel delivery system is not likely to have caused the Misfire DTC. GO to HD20 to diagnose the vacuum system. REPLACE or CLEAN the inoperative fuel injector(s) as required. RERUN Quick Test.</p><p><strong>HD20 CHECK VACUUM SYSTEM</strong></p><ul> <li data-xf-list-type="ul">Inspect all vacuum lines for damage, such as pinched lines, cracks, proper routing and assembly.<br /> <br /> </li> <li data-xf-list-type="ul">Refer to the Electrical and Vacuum Troubleshooting Manual (EVTM) for vacuum service information and repair.<br /> </li> </ul><p>Is the vehicle vacuum system OK?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD21. SERVICE the vacuum system. REFER to the Electrical and Vacuum Troubleshooting Manual. RERUN Quick Test.</p><p><strong>HD21 CHECK EVAPORATIVE EMISSION SYSTEM</strong></p><ul> <li data-xf-list-type="ul"><br /> The Misfire Monitor can be influenced by Evaporative Emission System. The next four Pinpoint Test steps will diagnose the Evaporative Emission System.</li> <li data-xf-list-type="ul">Check the fuel vapor storage canister for fuel saturation.<br /> </li> </ul><p>Is there an excess amount of liquid fuel present in the fuel vapor storage canister?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>REPLACE fuel vapor storage canister. RERUN Quick Test. GO to HD22. CHECK fuel tank vent system.</p><p><strong>HD22 PRESSURE TEST EVAPORATIVE EMISSION SYSTEM</strong></p><ul> <li data-xf-list-type="ul">Key OFF.<br /> <br /> </li> <li data-xf-list-type="ul">Install Rotunda Evaporative Emission System Tester 134-00056 or equivalent at the EVAP SERVICE port, if equipped, or the fuel filler cap.<br /> <br /> </li> <li data-xf-list-type="ul">Follow test instructions from the Tester Kit.<br /> </li> </ul><p>Is evaporative emission system holding pressure?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD23. SERVICE as necessary. RERUN Quick Test.</p><p><strong>HD23 CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM</strong></p><ul> <li data-xf-list-type="ul">Check for blockage/restrictions or cut hoses between engine vacuum port and fuel vapor storage canister.<br /> <br /> </li> <li data-xf-list-type="ul">Check for blockage in fuel tank vent system.<br /> </li> </ul><p>Is there a fault indicated?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>REPLACE damaged vacuum hoses, or REMOVE blockage/restrictions. RERUN Quick Test.</p><p>For vehicles with EVAP Canister Purge valve:</p><p></p><p>GO to HD24.</p><p></p><p>For vehicles with VMV:</p><p></p><p>GO to HD26.</p><p><strong>HD24 CHECK EVAP CANISTER PURGE VALVE</strong></p><ul> <li data-xf-list-type="ul"><br /> This pinpoint test step will verify the mechanical integrity of EVAP Canister Purge valve. The valve and circuit have been checked electrically and reported during KOEO Self-Test.</li> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Disconnect EVAP Canister Purge valve.<br /> <br /> </li> <li data-xf-list-type="ul">CAUTION: Observe proper pin orientation.<br /> <br /> </li> <li data-xf-list-type="ul">Connect 12 volt DC power source to valve.<br /> <br /> </li> <li data-xf-list-type="ul">Connect positive power source to VPWR circuit and negative lead to EVAP Canister Purge circuit at the EVAP Canister Purge valve harness connector.<br /> <br /> </li> <li data-xf-list-type="ul">Apply 53 kPa (16 in-Hg) of vacuum to the manifold side of the EVAP Canister Purge valve. Apply power source.<br /> </li> </ul><p>Does the valve open and pass air freely?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Evaporative Emission system is functioning properly. GO to HD25for Base Engine concerns. REPLACE EVAP Canister Purge valve. RERUN Quick Test.</p><p><strong>HD25 CHECK FOR BASE ENGINE CONCERNS</strong></p><ul> <li data-xf-list-type="ul"><br /> This Pinpoint Test step will determine if there are any base engine concerns that may have caused the Misfire DTC or drive concern.Perform the following tests in order to evaluate base engine integrity:</li> <li data-xf-list-type="ul">Perform an Engine Compression test.<br /> <br /> </li> <li data-xf-list-type="ul">Perform Dynamic Valve Train analysis.<br /> <br /> </li> <li data-xf-list-type="ul">Check Positive Crankcase Ventilation System.<br /> <br /> </li> <li data-xf-list-type="ul">Check possible leakage points.<br /> <br /> </li> <li data-xf-list-type="ul">Refer to the Diagnosis and Testing procedures in the Powertrain/Engine Group of the Service Manual for all of the above procedures.<br /> </li> </ul><p>Is any service required?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to Powertrain/Engine Group in the Service Manual, Diagnosis and Testing, to make repairs. RERUN Quick Test. The cause of the Misfire DTC is intermittent. To diagnose the Ignition System, GO to the Intermittent Ignition procedure in Pinpoint Test Step Z50. FOLLOW Instructions for using the Rotunda Electronic Ignition System, also known as the Distributor/less Ignition System Tester (DIST) tool.</p><p><strong>HD26 CHECK FOR VMV HOUSING LEAKS</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">VMV electrially connected.<br /> <br /> </li> <li data-xf-list-type="ul">Install a hand vacuum pump to the fuel vapor port to fuel vapor storage canister on the VMV vacuum at line.<br /> <br /> </li> <li data-xf-list-type="ul">Apply 53 kPa (16 in-Hg) of vacuum with the vacuum pump.<br /> </li> </ul><p>Does the VMV hold vacuum at room temperature?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD27. REMOVE vacuum pump. REPLACE damaged VMV. RECONNECT all components. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test.</p><p><strong>HD27 CHECK FOR FILTER CONTAMINATION OR DAMAGE ON VMV</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Vacuum line from input vacuum port to intake manifold on the VMV (control vacuum solenoid part of valve) is removed.<br /> <br /> </li> <li data-xf-list-type="ul">Install a hand held vacuum pump to the open input vacuum port on the VMV.<br /> <br /> </li> <li data-xf-list-type="ul">Apply 48-52 kPa (10-15 in-Hg) of vacuum to the VMV.<br /> </li> </ul><p>Does the VMV hold vacuum or is the valve very slow to release vacuum to atmosphere?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>SERVICE VMV filter. If unable to clean filter or REMOVE blockage to filter, REPLACE VMV. RECONNECT all components. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test. REMOVE vacuum pump. RECONNECT all components. GO to HD25.</p><p><strong>HD30 CHECK FOR ADDITIONAL MISFIRE DTCS</strong></p><p>Diagnostic Trouble Code P0300 indicates multiple cylinders are misfiring or PCM cannot identify which cylinder is misfiring.</p><p></p><p>Possible causes:</p><p></p><ul> <li data-xf-list-type="ul">Camshaft Position Sensor (CMP)<br /> <br /> </li> <li data-xf-list-type="ul">Low fuel: less than 1/8 tank<br /> <br /> </li> <li data-xf-list-type="ul">Stuck open EGR valve<br /> </li> </ul><p>Are any other misfire DTCs present?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>GO to HD1. GO to HD31.</p><p><strong>HD31 CHECK FOR OTHER CONTINUOUS MEMORY DTCS</strong></p><p>Are other Continuous Memory DTCs present?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>Go to Section 4A for Powertrain DTC Charts. PROCEED as required. GO to HD32.</p><p><strong>HD32 CHECK/COMPARE PID VALUES</strong></p><ul> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Connect Scan Tool.<br /> <br /> </li> <li data-xf-list-type="ul">Accessories off (A/C, heater, radio, etc.).<br /> <br /> </li> <li data-xf-list-type="ul">Start engine and warm to normal operating temperature.<br /> <br /> </li> <li data-xf-list-type="ul">Access DPFEGR PID with the Scan Tool.<br /> <br /> </li> <li data-xf-list-type="ul">Key on, engine off.<br /> <br /> </li> <li data-xf-list-type="ul">Record PID value.<br /> <br /> </li> <li data-xf-list-type="ul">Start engine, let idle.<br /> <br /> </li> <li data-xf-list-type="ul">Compare key on, engine off and engine running PID values.<br /> </li> </ul><p>Was engine running DPFEGR PID value within 0.15 volt of key on, engine off value?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p>DISCONNECT Scan Tool. GO to HD8. GO to Pinpoint Test Step HE100.</p><p><strong>HD40 CHECK CMP SENSOR OUTPUT</strong></p><ul> <li data-xf-list-type="ul"><br /> Diagnostic Trouble Code (DTC) P1309 indicates Misfire Detection Monitor is not enabled.</li> <li data-xf-list-type="ul">Key off.<br /> <br /> </li> <li data-xf-list-type="ul">Breakout box installed, PCM disconnected.<br /> <br /> </li> <li data-xf-list-type="ul">Connect digital multimeter between Test Pin 85 (CMP) and Test Pins 51 or 103 (PWR GND) at the breakout box.<br /> <br /> </li> <li data-xf-list-type="ul">Bump engine in short burst with the starter without starting engine for at least 10 engine revolutions.<br /> </li> </ul><p>Does digital multimeter reading switch between low (less than 2.0 volts DC) and high (greater than 8.0 volts DC)?</p><p></p><p></p><p><strong>Yes</strong> <strong>No</strong></p><p> REPLACE CMP sensor. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.</p><ul> <li data-xf-list-type="ul">Intro</li> </ul></blockquote><p></p>
[QUOTE="hotcobra03, post: 16279843, member: 53096"] [URL='https://app-na.readspeaker.com/cgi-bin/rsent?customerid=7827&lang=en_us&readid=dvRSContent&url=www.chiltonlibrary.com%2fRepair%2fReadArticleContent%2fmwellVaSq2DTHaW4SQe_LWG9rOvUVyU3ErXhmpuMCr92xjbQ1%7c176550%7c44549']Listen[/URL] [size=6][b]HD: Misfire Detection Monitor[/b][/size] 1997 PCED On Board Diagnostics II A SECTION 5A: Pinpoint Tests HD: Misfire Detection Monitor ← HD: Introduction [b]HD1 CHECK POSSIBLE CAUSES OF MISFIRE[/b] NOTE Note: Running out of fuel can turn on the MIL and possibly store a Continuous Misfire DTC. Misfire Continuous Memory Diagnostic Trouble Codes (DTCs): [LIST] [*]P0301 - Cyl No.1, Fuel Inj. Test Pin 75 [*]P0302 - Cyl No.2, Fuel Inj. Test Pin 101 [*]P0303 - Cyl No.3, Fuel Inj. Test Pin 74 [*]P0304 - Cyl No.4, Fuel Inj. Test Pin 100 [*]P0305 - Cyl No.5, Fuel Inj. Test Pin 73 [*]P0306 - Cyl No.6, Fuel Inj. Test Pin 99 [*]P0307 - Cyl No.7, Fuel Inj. Test Pin 72 [*]P0308 - Cyl No.8, Fuel Inj. Test Pin 98 [*]P0309 - Cyl No.9, Fuel Inj. Test Pin 68 [*]P0310 - Cyl No.10, Fuel Inj. Test Pin 42 [/LIST] Possible causes: [LIST] [*]Ignition System. [*]Fuel Injectors. [*]Fuel Pressure. [*]Evaporative Emission System. [*]EVAP Canister Purge Valve. [*]Base Engine. [*]Running out of fuel. [/LIST] Has the vehicle recently run out of fuel? [b]Yes[/b] [b]No[/b] OBD II system OK. COMPLETE PCM Reset to clear DTCs. RETURN vehicle to customer. GO to HD2. [b]HD2 CHECK DAMPER AND PULLEY ASSEMBLY[/b] [LIST] All others:CAUTION: Remove the front cover if necessary to observe the crank pulley. [*]Key off. [*]Observe the crank pulley for wobble. [*]Examine the EI pulse ring fastened to the harmonic fastener. [/LIST] Does the crank pulley wobble or is the pulse ring loose or damaged? [b]Yes[/b] [b]No[/b] REPLACE the pulley or damper assembly. RERUN Quick Test. GO to HD3. [b]HD3 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS[/b] NOTE Note: Check for other non-misfire Continuous Memory DTCs which could cause the misfire DTC. Possible causes: [LIST] [*]Camshaft Position (CMP) Sensor. [*]Octane Adjust (OCT ADJ). [*]Ignition Coil Primary Circuit. [*]Knock Sensor (KS). [/LIST] Are other non-misfire Continuous Memory DTCs present? [b]Yes[/b] [b]No[/b] ADDRESS the next Continuous Memory DTC. DISREGARD Misfire DTC at this time. Go to Section 4A for Powertrain DTC Charts. GO to HD4. [b]HD4 CHECK FOR ON-DEMAND SELF-TEST DTCS[/b] NOTE Note: Check for any key on, engine off DTCs which could cause the Misfire DTC. Are any key on, engine off DTCs displayed on the Scan Tool? [b]Yes[/b] [b]No[/b] Go to Section 4A, Powertrain DTC Charts, and PROCEED as required. Coil On Plug applications: GO to Pinpoint Test Step JF1. All others: GO to JB1 to evaluate spark plugs and secondary wires. If OK, GO to HD5. [b]HD5 CHECK FOR OTHER KEY ON ENGINE RUNNING DTCS[/b] NOTE Note: Check for any other key on, engine running DTCs which can cause the Misfire DTC. Are any additional key on, engine running DTCs displayed on the Scan Tool? [b]Yes[/b] [b]No[/b] If DTCs P1131, P1137, P1151 or P1157 are present, GO to HD8. All others: Go to Section 4A, Powertrain DTC Charts, and PROCEED as required. Vehicles with D.P.F. EGR Systems: GO to HD6. All others: GO to HD8. [b]HD6 CHECK/COMPARE PID VALUES[/b] [LIST] [*]Key off. [*]Connect Scan Tool. [*]Accessories off (A/C, heater, etc.). [*]Start engine and warm to normal operating temperature. [*]Access DPFEGR PID with the Scan Tool. [*]Key on, engine off. [*]Record DPFEGR PID value. [*]Start engine, let idle. [*]Compare key on, engine off and engine running PID values. [/LIST] Was engine running PID value within 0.15 volt of key on, engine off value? [b]Yes[/b] [b]No[/b] Disconnect Scan Tool. GO to HD8. GO to Pinpoint Test Step HE100. [b]HD8 CHECK RESISTANCE OF FUEL INJECTOR(S) AND HARNESS[/b] [LIST] [*]Key off. [*]Disconnect PCM. Inspect for damaged or pushed out pins, corrosion and loose wires. Service as necessary. [*]Install breakout box, leave PCM disconnected. [*]Measure resistance between suspect fuel injector test pin and Test Pin 71 or 97 at the breakout box. Refer to the list in HD1. [/LIST] Is the resistance between 11.0-18.0 ohms? [b]Yes[/b] [b]No[/b] Fuel injector and harness resistance is OK. GO to HD9. GO to Pinpoint Test Step H56 to diagnose fuel injectors. [b]HD9 CHECK INJECTOR DRIVER SIGNAL[/b] [LIST] [*]Key off. [*]Breakout box installed. [*]Connect PCM to breakout box. [*]Connect Test Lamp between Test Pin 71 or 97 and suspect injector test pin. [*]Start engine. [/LIST] Does test lamp have a dim glow while running engine? [b]Yes[/b] [b]No[/b] GO to HD10. No light or bright light: REPLACE PCM. REMOVE breakout box. RERUN Quick Test. [b]HD10 CHECK FUEL PRESSURE[/b] [LIST] WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHILE WORKING ON THE FUEL SYSTEM. [*]Key off. [*]Install fuel pressure gauge. [*]Start and run engine at idle. Record fuel pressure. [*]Increase engine speed to 2500 rpm and maintain for one minute. Note and compare fuel pressure. [/LIST] Is fuel pressure between 210-310 kPa (30-45 psi)? [b]Yes[/b] [b]No[/b] GO to HD11. GO to Powertrain/Fuel System Group in the Service Manual. [b]HD11 CHECK ABILITY OF FUEL SYSTEM TO HOLD FUEL PRESSURE[/b] [LIST] [*]Start and run engine at idle. Note fuel pressure. [*]Increase engine speed to 2500 rpm and maintain for one minute. [*]Look for fuel leaking at the fuel injector O-ring, fuel pressure regulator and the fuel lines to the fuel charging assembly. Service as necessary. [*]Turn engine off. [*]Key on, engine off. [/LIST] Does fuel pressure remain at specification within 16.5 kPa (5 psi) for 60 seconds? [b]Yes[/b] [b]No[/b] GO to HD12. GO to Powertrain/Engine or Fuel System Group in the Service Manual to determine which area within the Fuel Delivery System is at fault. [b]HD12 CHECK FUEL INJECTOR FOR FLOW AND LEAKAGE[/b] [LIST] [*]Refer to Warning, Caution and Handling at the beginning of Pinpoint Test HC to avoid fuel spillage and injury. [*]Verify that the flow rate for each fuel injector is within specification using Injector Flow Tester. [/LIST] Is flow rate for each fuel injector within specification? [b]Yes[/b] [b]No[/b] Fuel delivery system is not likely to have caused the Misfire DTC. GO to HD20 to diagnose the vacuum system. REPLACE or CLEAN the inoperative fuel injector(s) as required. RERUN Quick Test. [b]HD20 CHECK VACUUM SYSTEM[/b] [LIST] [*]Inspect all vacuum lines for damage, such as pinched lines, cracks, proper routing and assembly. [*]Refer to the Electrical and Vacuum Troubleshooting Manual (EVTM) for vacuum service information and repair. [/LIST] Is the vehicle vacuum system OK? [b]Yes[/b] [b]No[/b] GO to HD21. SERVICE the vacuum system. REFER to the Electrical and Vacuum Troubleshooting Manual. RERUN Quick Test. [b]HD21 CHECK EVAPORATIVE EMISSION SYSTEM[/b] [LIST] The Misfire Monitor can be influenced by Evaporative Emission System. The next four Pinpoint Test steps will diagnose the Evaporative Emission System. [*]Check the fuel vapor storage canister for fuel saturation. [/LIST] Is there an excess amount of liquid fuel present in the fuel vapor storage canister? [b]Yes[/b] [b]No[/b] REPLACE fuel vapor storage canister. RERUN Quick Test. GO to HD22. CHECK fuel tank vent system. [b]HD22 PRESSURE TEST EVAPORATIVE EMISSION SYSTEM[/b] [LIST] [*]Key OFF. [*]Install Rotunda Evaporative Emission System Tester 134-00056 or equivalent at the EVAP SERVICE port, if equipped, or the fuel filler cap. [*]Follow test instructions from the Tester Kit. [/LIST] Is evaporative emission system holding pressure? [b]Yes[/b] [b]No[/b] GO to HD23. SERVICE as necessary. RERUN Quick Test. [b]HD23 CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM[/b] [LIST] [*]Check for blockage/restrictions or cut hoses between engine vacuum port and fuel vapor storage canister. [*]Check for blockage in fuel tank vent system. [/LIST] Is there a fault indicated? [b]Yes[/b] [b]No[/b] REPLACE damaged vacuum hoses, or REMOVE blockage/restrictions. RERUN Quick Test. For vehicles with EVAP Canister Purge valve: GO to HD24. For vehicles with VMV: GO to HD26. [b]HD24 CHECK EVAP CANISTER PURGE VALVE[/b] [LIST] This pinpoint test step will verify the mechanical integrity of EVAP Canister Purge valve. The valve and circuit have been checked electrically and reported during KOEO Self-Test. [*]Key off. [*]Disconnect EVAP Canister Purge valve. [*]CAUTION: Observe proper pin orientation. [*]Connect 12 volt DC power source to valve. [*]Connect positive power source to VPWR circuit and negative lead to EVAP Canister Purge circuit at the EVAP Canister Purge valve harness connector. [*]Apply 53 kPa (16 in-Hg) of vacuum to the manifold side of the EVAP Canister Purge valve. Apply power source. [/LIST] Does the valve open and pass air freely? [b]Yes[/b] [b]No[/b] Evaporative Emission system is functioning properly. GO to HD25for Base Engine concerns. REPLACE EVAP Canister Purge valve. RERUN Quick Test. [b]HD25 CHECK FOR BASE ENGINE CONCERNS[/b] [LIST] This Pinpoint Test step will determine if there are any base engine concerns that may have caused the Misfire DTC or drive concern.Perform the following tests in order to evaluate base engine integrity: [*]Perform an Engine Compression test. [*]Perform Dynamic Valve Train analysis. [*]Check Positive Crankcase Ventilation System. [*]Check possible leakage points. [*]Refer to the Diagnosis and Testing procedures in the Powertrain/Engine Group of the Service Manual for all of the above procedures. [/LIST] Is any service required? [b]Yes[/b] [b]No[/b] GO to Powertrain/Engine Group in the Service Manual, Diagnosis and Testing, to make repairs. RERUN Quick Test. The cause of the Misfire DTC is intermittent. To diagnose the Ignition System, GO to the Intermittent Ignition procedure in Pinpoint Test Step Z50. FOLLOW Instructions for using the Rotunda Electronic Ignition System, also known as the Distributor/less Ignition System Tester (DIST) tool. [b]HD26 CHECK FOR VMV HOUSING LEAKS[/b] [LIST] [*]Key off. [*]VMV electrially connected. [*]Install a hand vacuum pump to the fuel vapor port to fuel vapor storage canister on the VMV vacuum at line. [*]Apply 53 kPa (16 in-Hg) of vacuum with the vacuum pump. [/LIST] Does the VMV hold vacuum at room temperature? [b]Yes[/b] [b]No[/b] GO to HD27. REMOVE vacuum pump. REPLACE damaged VMV. RECONNECT all components. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test. [b]HD27 CHECK FOR FILTER CONTAMINATION OR DAMAGE ON VMV[/b] [LIST] [*]Key off. [*]Vacuum line from input vacuum port to intake manifold on the VMV (control vacuum solenoid part of valve) is removed. [*]Install a hand held vacuum pump to the open input vacuum port on the VMV. [*]Apply 48-52 kPa (10-15 in-Hg) of vacuum to the VMV. [/LIST] Does the VMV hold vacuum or is the valve very slow to release vacuum to atmosphere? [b]Yes[/b] [b]No[/b] SERVICE VMV filter. If unable to clean filter or REMOVE blockage to filter, REPLACE VMV. RECONNECT all components. COMPLETE PCM Reset to clear DTCs. RERUN Quick Test. REMOVE vacuum pump. RECONNECT all components. GO to HD25. [b]HD30 CHECK FOR ADDITIONAL MISFIRE DTCS[/b] Diagnostic Trouble Code P0300 indicates multiple cylinders are misfiring or PCM cannot identify which cylinder is misfiring. Possible causes: [LIST] [*]Camshaft Position Sensor (CMP) [*]Low fuel: less than 1/8 tank [*]Stuck open EGR valve [/LIST] Are any other misfire DTCs present? [b]Yes[/b] [b]No[/b] GO to HD1. GO to HD31. [b]HD31 CHECK FOR OTHER CONTINUOUS MEMORY DTCS[/b] Are other Continuous Memory DTCs present? [b]Yes[/b] [b]No[/b] Go to Section 4A for Powertrain DTC Charts. PROCEED as required. GO to HD32. [b]HD32 CHECK/COMPARE PID VALUES[/b] [LIST] [*]Key off. [*]Connect Scan Tool. [*]Accessories off (A/C, heater, radio, etc.). [*]Start engine and warm to normal operating temperature. [*]Access DPFEGR PID with the Scan Tool. [*]Key on, engine off. [*]Record PID value. [*]Start engine, let idle. [*]Compare key on, engine off and engine running PID values. [/LIST] Was engine running DPFEGR PID value within 0.15 volt of key on, engine off value? [b]Yes[/b] [b]No[/b] DISCONNECT Scan Tool. GO to HD8. GO to Pinpoint Test Step HE100. [b]HD40 CHECK CMP SENSOR OUTPUT[/b] [LIST] Diagnostic Trouble Code (DTC) P1309 indicates Misfire Detection Monitor is not enabled. [*]Key off. [*]Breakout box installed, PCM disconnected. [*]Connect digital multimeter between Test Pin 85 (CMP) and Test Pins 51 or 103 (PWR GND) at the breakout box. [*]Bump engine in short burst with the starter without starting engine for at least 10 engine revolutions. [/LIST] Does digital multimeter reading switch between low (less than 2.0 volts DC) and high (greater than 8.0 volts DC)? [b]Yes[/b] [b]No[/b] REPLACE CMP sensor. REMOVE breakout box. RECONNECT all components. RERUN Quick Test. [LIST] [*]Intro [/LIST] [/QUOTE]
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