Ignition Timing: Testing and Inspection

Ignition Timing Inspection

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) Initial Inspection and Diagnostic Overview.

2. Turn the ignition switch to ON (II).

3. Make sure the HDS communicates with the vehicle and the engine control module (ECM)/powertrain control module (PCM). If it doesn't communicate, troubleshoot the DLC circuit Testing and Inspection.

4. Start the engine. Hold the engine speed at 3,000 rpm with no load (in P or N) (A/T model) or neutral (M/T model) until the radiator fan comes on, then let it idle.

5. Check the idle speed Testing and Inspection.

6. Jump the SCS line with the HDS.

7. Connect the timing light to the service loop (white tape).






8. Aim the light toward the pointer (A) on the cam chain case and the timing mark (B) on the crankshaft pulley. Check the ignition timing under a no load condition (headlights, blower fan, rear window defogger, and air conditioner are turned off).









9. If the ignition timing differs from the specification, check the cam timing. If the cam timing is OK, update the ECM/PCM, if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM Initial Inspection and Diagnostic Overview, then recheck. If the system works properly, and the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.

10. Disconnect the HDS and the timing light.