Diagnostic Test
- DTC IS ACTIVE
- Diagnose and repair any other active component or circuit DTCs before continuing with this procedure.
- Turn the ignition on.
- With the scan tool, select View DTCs. Copy DTC and Freeze Frame information.
- Start the engine and allow it to reach operating temperature.WARNING:
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
NOTE:Attempt to operate the vehicle under conditions similar to which the DTC was set.
NOTE:It may be necessary to test drive the vehicle within the DTC monitoring conditions in order for this DTC to set.
- With a scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE FUEL DELIVERY SYSTEM
- Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START)
.
Were any problems found with the fuel system?
Yes
- Perform the appropriate repair.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 3
- Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START)
.
- ECT SENSOR OPERATION NOTE:
For this test to be valid, the thermostat must be operating correctly.
NOTE:This test works best if performed on a cold engine (cold soak).
- Ignition on, engine not running.
- With the scan tool, read the Engine Coolant Temperature (ECT) Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature.NOTE:
If engine coolant temperature is above 82°C (180°F), allow the engine to cool until 65°C (150°F) is reached.
- Start the Engine.
- During engine warm-up, monitor the ECT Sensor value. The temperature value change should be a smooth transition from start up to normal operating temperature 82°C (180°F). The value should reach at least 82°C (180°F).
Did the ECT value increase smoothly and did it reach at least 82°C (180°F)?
Yes
- Go To 4
No
- Verify that there is good pin to terminal contact in the ECT Sensor and Powertrain Control Module connectors. If OK, replace the Engine Coolant Temperature Sensor. Refer to SENSOR, COOLANT TEMPERATURE, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE MAP SENSOR OPERATION
- Perform the CHECKING THE MAP SENSOR OPERATION test procedure. Refer to CHECKING THE MAP SENSOR OPERATION
.
Were any problems found with the MAP Sensor?
Yes
- Perform the appropriate repair.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 5
- Perform the CHECKING THE MAP SENSOR OPERATION test procedure. Refer to CHECKING THE MAP SENSOR OPERATION
.
- CHECK THE OXYGEN SENSOR OPERATION
- Perform the CHECKING THE OXYGEN SENSOR OPERATION diagnostic procedure. Refer to DIAGNOSIS AND TESTING
.
Were any problems found?
Yes
- Repair as necessary in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 6
- Perform the CHECKING THE OXYGEN SENSOR OPERATION diagnostic procedure. Refer to DIAGNOSIS AND TESTING
.
- ENGINE MECHANICAL
- Turn the ignition off.
- Check for any of the following conditions/mechanical problems:
- AIR INDUCTION SYSTEM - must be free from leaks.
- ENGINE VACUUM - must be at least 13 inches in neutral
- ENGINE VALVE TIMING - must be within specifications
- ENGINE COMPRESSION - must be within specifications
- ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.
- ENGINE PCV SYSTEM - must flow freely
- TORQUE CONVERTER STALL SPEED - must be within specifications
- POWER BRAKE BOOSTER - no internal vacuum leaks
- FUEL - must be free of contamination
- FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector
Are there any engine mechanical problems?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 7
- POWERTRAIN CONTROL MODULE (PCM)
- Using the wiring diagram/schematic as a guide, inspect the wiring and connectors relative to the components tested in this procedure.
- Monitor the scan tool data relative to the components tested in this procedure and wiggle test the wiring and connectors.
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals.
- Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Replace and program the Powertrain Control Module (PCM) in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL and PROGRAM THE PCM (POWERTRAIN CONTROL MODULE) .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .