QT: Step 1: PCM Quick Test

QT1 PERFORM PCM QUICK TEST

Note: If the vehicle was brought in with an emission compliance failure symptom, GO directly to Section 5; GO to EM1 See: EM: Emissions Compliance - Pinpoint Test.

• Complete preliminary checks looking for obvious concerns that may relate to the symptom. Check items such as those listed:
• Related electrical connectors or fuses
• Vacuum lines (leaks, routing)
• Air intake system (leaks, restrictions)
• Fuel quality (octane, contamination, winter/summer blend)
• Cooling system (engine operating at proper temperature)
• Access any related OASIS or TSB information (if available).
• Complete PCM Quick Test to access any DTCs. Note any Key On Engine Off, Key On Engine Running (if engine runs) and Continuous Memory (MIL and non-MIL) DTCs.

Note: If unable to access DTCs, or any scan tool communication concern exists, GO to QA1 See: QA: Unable To Activate Self-Test/SCP Communication Error/DTC Not Listed - Pinpoint Test in Section 5. For additional information on retrieving MIL and non-MIL DTCs, refer to Section 2, Diagnostic Methods See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 2: Diagnostic Methods\Diagnostic Methods (Continuous Memory Self-Test).
Were any DTCs present?
Yes

• If engine runs rough at idle and Key On Engine Running or Continuous Memory DTC(s) are present:
• GO to Quick Test QT2

to check injector fault PIDS.

• All Others:
• GO to Section 4 See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions (Diagnostic Trouble Code (DTC) Charts) for direction to service DTC(s) after noting the following:
• Service DTCs in the following order (for each mode, begin diagnosis with the first DTC output).

1. Any KOEO DTC(s)
2. Any KOER DTC(s)
3. Any Continuous

Memory DTC(s) (retrieve any available Freeze Frame Data)(disregard any
identical/related Continuous DTC(s) of DTC(s) already serviced).

No

• GO to Step 2: NO DTC(s) PRESENT SYMPTOM CHART INDEX for direction to proper STEP 3 Chart. See: Symptom Related Diagnostic Procedures\Step 2: No DTC(s) Present Symptom Chart Index

Note: If symptom is not listed, REFER to applicable diagnostic/repair information or GO to Z1 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\Z: Intermittent - Pinpoint Test in Section 5 (for intermittent PCM system diagnostics).

QT2 ENGINE RUNS ROUGH AT IDLE WITH KEY ON ENGINE RUNNING OR CONTINUOUS MEMORY DTC(s): CHECK INJECTOR FAULT (INJxF) PID(s)

Note: An injector circuit fault could result in unrelated DTC(s) being received from the PCM.

• Key on, engine off.
• Access the INJxF PIDs (the "x" indicates the injector number). There will be one INJxF PID for each engine cylinder.

Do any of the INJxF PIDs indicate "Yes"?
Yes

• An injector circuit fault exists. KEY OFF. Disregard DTC(s).
• For Natural Gas applications:
• GO to HA60 See: HA: Natural Gas Fuel Control - Pinpoint Test

.

• All Others:
• GO to H61 See: Diagnostic Trouble Code Tests and Associated Procedures\SECTION 5: Pinpoint Tests\H: Fuel Control - Pinpoint Test

.

No

• No fault detected by injector fault PIDs. KEY OFF. GO to Quick Test QT1

and follow the YES Action To Take for all others.