Diagnostic Procedure

If diagnostic system check has already been performed, go to next step. If diagnostic system check has not been performed, go to DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.2L CTS article.
Turn ignition ON, with engine OFF. Observe DTC information using a scan tool. Is DTC P0201-P0206, P0261, P0264, P0267, P0270, P0273, P0276, P0335, P1629, P1630, P1631 or P2105 set? If yes, diagnose affected DTC(s). See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF DIAGNOSTICS - 3.2L CTS article. If no DTC(s) are set, go to next step.
Test ground circuits of Engine Control Module (ECM) for high resistance or an open. Did you find and correct a ground circuit condition? If yes, go to step 10. If no, go to next step.
Test the ground circuit between the battery and the body for high resistance or for an open. Did you find and correct a ground circuit condition? If yes, go to step 10. If no, go to next step.
Observe the ECM in VTD FAIL ENABLE STATUS parameter using a scan tool. Does the scan tool display an ECM in VTD FAIL ENABLE STATUS of NO? If yes, go to next step. If no, see appropriate THEFT DETERRENT DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in ANTI-THEFT SYSTEMS - CTS article.

NOTE: Inspect the fuel system for damage or external leaks before proceeding with this diagnostic procedure.

Turn ignition ON, with engine OFF. Command the fuel pump relay ON using a scan tool. Does the fuel pump operate? If fuel pump operates, go to next step. If fuel pump does not operate, see FUEL PUMP ELECTRICAL CIRCUIT DIAGNOSIS .
Perform the following:
1. Turn ignition OFF.
2. Remove the coil pack from the engine.
3. Leave the electrical connector connected.
4. Disconnect the fuel injector harness multi-connector.
5. Install Spark Tester into one coil and connect it to a good ground.
6. Turn ignition ON, with engine OFF.
7. Operate the ignition coil using a scan tool.
8. Repeat above steps for each of the remaining coils.
If the Spark Tester shows spark on all cylinders, go to next step. If Spark Tester does not show spark on all cylinders, see ELECTRONIC IGNITION SYSTEM DIAGNOSIS under IGNITION SYSTEMS.
Perform the following:
1. Turn ignition OFF.
2. Install a fuel pressure gauge.
3. Turn ignition ON, with engine OFF.
4. Command fuel pump ON using a scan tool. It may be necessary to command fuel pump on a few times in order to obtain the highest possible fuel pressure.
5. Observe the fuel pressure gauge, with the fuel pump commanded ON.
Is the fuel pressure within 49-55 psi (337-379 kPa)? If yes, go to next step. If no, see FUEL SYSTEM DIAGNOSIS under FUEL SYSTEMS.
Inspect for the following conditions:
- Fouled spark plugs. If the spark plugs are fouled, determine the cause of the fouling before replacing them.
- Water or alcohol contaminated fuel. See ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITH SPECIAL TOOL or ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS WITHOUT SPECIAL TOOL under FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - 3.2L CTS article.
- A restricted exhaust. See RESTRICTED EXHAUST under SYMPTOMS in TROUBLE SHOOTING - NO CODES - 3.2L CTS article.
- An engine mechanical condition that would cause the engine not to start, such as low compression, broken timing belt, bent or burned intake or exhaust valves. See ENGINE COMPRESSION TEST under MECHANICAL INSPECTION in PRELIMINARY INSPECTION & ADJUSTMENTS.
- A collapsed or leaking air intake duct.
- A skewed Engine Coolant Temperature (ECT) sensor. See ENGINE COOLANT TEMPERATURE SENSOR under SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - 3.2L CTS article.
If any problems are found, repair as necessary. After repairs are complete, go to next step. If no problems are found, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - 3.2L CTS article.
Using a scan tool, clear DTCs. Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, go to step 2.
Allow engine to idle. Ensure engine is at normal operating range. Using a scan tool, observe DTC information. If any DTCs are set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 3.2L CTS article. If scan tool does not display any DTCs, system is okay.