Troubleshooting Hints

Before suspecting the ECU system as the cause of a driveability problem, check operation and condition of the following interrelated systems.
1. Power supply: check battery, fuses, electrical connections and fuse links.
2. Body ground: check and ensure for proper body ground attachment.
3. Fuel supply: check for fuel leakage and correct as required. Check fuel filter and pump for correct operation.
4. Ignition system: check spark plugs, spark plug cables, distributor, igniter and ignition coil.
5. Air induction system: check and correct and vacuum leaks.
6. Emission control system: check PCV and EGR systems.
7. ESA and ISC systems: check for correct ignition timing and idle speed adjustments.