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Ignition Timing: Testing and Inspection

Ignition Timing Inspection

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC), and check for DTC's. If a DTC is present, diagnose and repair the cause before inspecting the ignition timing.
2. Start the engine. Hold the engine at 3,000 rpm with no load (in Neutral) until the radiator fan comes on, then let it idle.
3. Check the idle speed.
4. Follow the tester's prompts to get the tester in the "SCS" mode.




5. Free the service loop from the wire harness, then connect the timing light to the service loop.




6. Aim the light toward the pointer (A) on the cam chain case. Check the ignition timing under no load condition: headlights, blower fan, rear window defogger, and air conditioner are not operating.
7. If the ignition timing differs from the specification, check cam timing. If cam timing is OK, update the engine control module (ECM)/powertrain control module (PCM) if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the system work properly, and the ECM/PCM was substituted, replace the original ECM/PCM.

8. Disconnect the HDS and the timing light.
9. Secure the service loop to the wire harness with wire ties.