| 1 |
Did you perform the Diagnostic System Check? |
- |
Go to Step 2 |
Go to On-Board Diagnostic (OBD II) System Check |
| 2 |
- Idle the engine at the normal operating temperature.
- The fuel system is in Closed Loop.
- Observe the Total Fuel Trim Avg. parameter with a scan tool.
Is the Total Fuel Trim Avg. less than the specified value indicated? |
40% |
Go to Step 3 |
Go to Step 4 |
| 3 |
- Observe the Freeze Frame and/or the Failure Records data for this DTC.
- Turn the ignition OFF for 30 seconds.
- Start the engine.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame and/or the Failure Records data.
Does the DTC fail this ignition cycle? |
- |
Go to Step 4 |
Go to Diagnostic Aids |
| 4 |
- Start the engine.
- Disconnect the MAP sensor harness connector while the engine is operating.
- Observe the Short Term FT parameter with a scan tool.
- Connect the MAP sensor after completing this step.
Does the Short Term FT parameter change more than the specified value with the MAP sensor disconnected? |
20% |
Go to Step 6 |
Go to Step 5 |
| 5 |
Inspect for the following conditions:
- The vacuum hoses for splits, kinks and proper connections
- The throttle body and the intake manifold for vacuum leaks
- The crankcase ventilation valve and system for leaks
- Contaminated fuel
- Lean injectors
- The engine control grounds for being clean, tight and in the correct locations
- An engine mechanical condition
Did you find and correct the condition? |
- |
Go to Step 6 |
Go to "Fuel System Diagnosis" |
| 6 |
- Turn the ignition OFF for 30 seconds.
- Start the engine.
- Reset the fuel trim system with a scan tool.
- Operate the vehicle within the Conditions for Setting the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.
Did the DTC fail this ignition? |
- |
Go to Step 2 |
Go to Step 7 |
| 7 |
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed? |
- |
Go to applicable DTC table |
System OK |