Diagnostic Test
- LOW COOLANT LEVEL
- Diagnose all other DTCs before continuing.
- Check the cooling system to make sure that the coolant is in good condition, at the proper level, and meets OEM specifications. Refer to DIAGNOSIS AND TESTING
.
Is the coolant level and condition OK?
Yes
- Go To 2
No
- Inspect the vehicle for a coolant leak and add the necessary amount of coolant. Refer to TECHNICAL SPECIFICATIONS .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- CHECK FOR AN ACTIVE DTC
- Start the engine.
- Allow the engine to reach normal operating temperature.
- Test drive the vehicle under the conditions in which the fault originally set by reviewing the Freeze Frame data.
- With the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?
Yes
- Go To 3
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- CHECK THE EGR SYSTEM AND PLUMBING FOR A LEAK
- Visually inspect the EGR System for a leak between the EGR Cooler and the EGR Valve for signs of a leak (I.E. loose connections or damaged plumbing.
Were any problems found?
Yes
- Perform the appropriate repair.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- Visually inspect the EGR System for a leak between the EGR Cooler and the EGR Valve for signs of a leak (I.E. loose connections or damaged plumbing.
- CHECK COOLING SYSTEM OPERATION
- Check the following cooling system components:
- Verify condition and operation of the accessory belt and tensioner.
- Verify proper airflow through the radiator.
- Verify that the Thermostat is opening correctly.
- Verify the correct coolant flow throughout the system.
- During engine warm-up, monitor the coolant temperature and the operation of the Cooling Fan.
Is the Cooling system operating correctly?
Yes
- Go To 5
No
- Perform the appropriate repairs.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- Check the following cooling system components:
- 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 6
- Perform the CHECKING THE FUEL DELIVERY SYSTEM test procedure. Refer to CHECKING THE FUEL DELIVERY SYSTEM (HARD START)
.
- ENGINE MECHANICAL
- Turn the ignition off.
- Check for any of the following conditions/mechanical problems:
- AIR INTAKE SYSTEM - must be free from leaks.
- ENGINE VACUUM - check the engine for vacuum leaks.
- ENGINE VALVE TIMING - 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
- Replace the EGR Temperature Sensor in accordance with the Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .