Initial Inspection

The On-Board Diagnostic (OBD) System Check is an organized approach for identifying a problem caused by the Fuel Injection System.

Driver comments normally fall into one of the following areas:

- Steady Malfunction Indicator Lamp (MIL) with Engine running.
- Driveability Problem.
- Engine "Cranks But Will Not Run"

Understanding the diagnostic chart and using it correctly will reduce diagnosis time and prevent the unnecessary replacement of parts.








1. A steady MIL with the Ignition "ON" and Engine stopped confirms Battery and Ignition voltage to the Engine Control Module (ECM).
2. Connect the Diagnostic Trouble Code (DTC) Test Terminals with each other, near ECM connector. The ECM will cause the MIL to flash DTC 12, indicating that the ECM diagnostics are working. DTC 12 will flash three (3) times, followed by any other DTCs stored in the memory. Each additional DTC will flash three (3) times, starting with the lowest DTC and then start over again with DTC 12. If there are no other DTCs, DTC 12 will flash until the DTC Test terminals are disconnected or the Engine is started. If a TECH 1 Scan is available, it can be connected to the Data Link Connector (DLC), also located by the ECM, to obtain DTCs.
3. Record all stored DTCs except for DTC 12. If the problem is "Engine Cranks But Will Not Run", refer to Diagnosis by Symptom / Hard Start. Hard Start
4. If no additional DTCs were recorded, see driveability symptoms and recommended service procedures.
5. Road test of the system should be done, under the safety conditions and traffic rules. If available, it will be better to use a chassis Dynamometer.
6. Clearing DTCs: Ignition "OFF", remove fuse No. 3 (10A) located in the Fuse Block in the lower-left part of the Instrument panel or Main Fuse (60A) in the Fuse and Relay box of Engine Compartment or disconnect Battery cable.