QT1 CARRY OUT THE PCM QUICK TEST
Note. If the vehicle was brought in with an emission compliance concern, refer to PINPOINT TEST EM - EMISSION COMPLIANCE .
Note. For applications that use a stand-alone transmission control module (TCM), the PCM does not output TCM related diagnostic trouble codes (DTCs). Refer to the Workshop Manual Section 307-01, Automatic Transaxle/Transmission, diagnostic strategy to continue diagnosis.
Note. If unable to access the PCM DTCs, or a scan tool communication concern exists, refer to PINPOINT TEST QA - UNABLE TO ACTIVATE SELF-TEST/NETWORK COMMUNICATION ERROR. For additional information on retrieving malfunction indicator lamp (MIL) and non-MIL DTCs, refer to QUICK TEST DESCRIPTION for the Continuous Memory Self-Test.
- Complete the preliminary checks looking for obvious concerns that may relate to the symptom. Check for the following items: fuses electrical circuits and connectors vacuum lines (leaks, routing) air intake system (leaks, restrictions) fuel quality (octane, contamination, winter/summer blend) cooling system (engine operating at correct temperature)
- Access any related On-line Automotive Service Information System (OASIS) or Technical Service Bulletin (TSB) information (if available).
- Carry out the PCM self-test to access any DTCs. Record any key on engine off (KOEO), key on engine running (KOER) (if the engine runs) and continuous memory (MIL and non-MIL) DTCs.
- Are any DTCs present?
| Yes | No |
|---|---|
| GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS for direction to repair DTCs after noting the following: DIAGNOSE the DTCs in the following order (begin diagnosis with the first DTC output in that mode and diagnose any circuit related DTCs first). For multiple circuit DTCs that are set as a result of a concern with more than one component, REFER to the Wiring Diagrams Manual Electronic Engine Controls Cell and identify the common cause such as SIGRTN, VREF, or VPWR. Continue DTC diagnosis by referring to the appropriately identified pinpoint test. Any KOEO self-test DTCs Any KOER self-test DTCs Any continuous memory self-test DTCs. Retrieve any available freeze frame data and disregard any identical/related continuous DTCs already repaired. | GO to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for direction to the correct symptom chart in NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHARTS. If the symptom is not listed, REFER to the applicable Workshop Manual Section to continue diagnosis. |
No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index
| System/Symptom | Chart Number | |
|---|---|---|
| Starting Concerns | Hard Start/Long Crank/Erratic Start/Erratic Crank | CHART NUMBER: 2 |
| No crank | CHART NUMBER: 23 | |
| No start (engine cranks) | CHART NUMBER: 3 | |
| Unique Idle Concerns | Slow return to idle | CHART NUMBER: 4 |
| Rolling idle | CHART NUMBER: 1 | |
| Fast idle | CHART NUMBER: 5 | |
| Low/Slow idle | CHART NUMBER: 6 | |
Driveability
| System/Symptom | Chart Number | |
|---|---|---|
| Stalls/Quits | Idle/Acceleration/Cruise | CHART NUMBER: 1 |
| Deceleration | CHART NUMBER: 6 | |
| Stall after start | CHART NUMBER: 1 | |
| Runs Rough | CHART NUMBER: 1 | |
| Misses | CHART NUMBER: 1 | |
| Buck/Jerk | CHART NUMBER: 1 | |
| Hesitation/Stumble | CHART NUMBER: 1 | |
| Surge | CHART NUMBER: 1 | |
| Backfires | CHART NUMBER: 7 | |
| Lack/Loss of Power | CHART NUMBER: 8 | |
| Spark Knock | CHART NUMBER: 9 | |
Driveability - Performance While Driving Concerns
Note: OASIS identifiers (the x means any number (1-9) can be used) xxx4xx equals during idle, xxx5xx equals during acceleration, xxx6xx equals during cruise, xxx7xx equals during deceleration.
| System/Symptom | Chart Number | |
|---|---|---|
| Diesels/Runs On | CHART NUMBER: 5 | |
| Poor Fuel Economy | CHART NUMBER: 10 | |
| Emissions Compliance | CHART NUMBER: 11 | |
Additional Driveability Concerns
| System/Symptom | Chart Number | |
|---|---|---|
| Warning Indicators | Malfunction indicator lamp (MIL) | CHART NUMBER: 12 |
| Transmission control indicator lamp (TCIL) | CHART NUMBER: 12 | |
| Power take off (PTO) | CHART NUMBER: 12 | |
| Temperature warning indicator or gauge (for vehicles equipped with a cylinder head temperature (CHT) sensor only) | CHART NUMBER: 12 | |
| Check fuel cap indicator | CHART NUMBER: 12 | |
| Powertrain malfunction indicator (wrench) | CHART NUMBER: 12 | |
| Climate Control | Lack of A/C cooling, A/C not functioning | CHART NUMBER: 21 |
| A/C always on or A/C compressor runs continuously | CHART NUMBER: 21 | |
| Instrumentation | Tachometer inoperative | CHART NUMBER: 14 |
| Speedometer/odometer inoperative | CHART NUMBER: 14 | |
| Boost gauge indicates higher than normal boost | CHART NUMBER: 14 | |
| Fuel gauge inoperative | CHART NUMBER: 14 | |
Electrical
| System/Symptom | Chart Number | |
|---|---|---|
| Oil System Concerns | High oil consumption | CHART NUMBER: 15 |
| Leaks | CHART NUMBER: 15 | |
| Cooling System Concerns | Electric cooling fan(s) does not operate (low, medium, high or variable speed) | CHART NUMBER: 16 |
| Cooling fan clutch does not operate | CHART NUMBER: 16 | |
| Electric cooling fan(s) always runs | CHART NUMBER: 17 | |
| Exhaust System Concerns | Visible smoke | CHART NUMBER: 18 |
| Odor (sulfur or rotten egg smell) | CHART NUMBER: 22 | |
| Fuel System Concerns | Odor, engine compartment | CHART NUMBER: 19 |
| Engine Noise (under hood) | CHART NUMBER: 20 | |
Engine
| System/Symptom | Chart Number | |
|---|---|---|
| Automatic Transmission (A/T) Shift Concerns | Upshift | CHART NUMBER: 13 |
| Downshift | CHART NUMBER: 13 | |
| Engagement | CHART NUMBER: 13 | |
Driveline
| System/Symptom | Chart Number | |
|---|---|---|
| PTO Concerns | Not working correctly | CHART NUMBER: 12 |
Power Take Off (PTO)