Ignition Timing: Testing and Inspection

Ignition Timing Inspection

1. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC), and check for DTCs. If a DTC is present, diagnose and repair the cause before inspecting the ignition timing.
2. Turn the ignition switch to ON (II).
3. '06-08 models: Make sure the HDS communicates with the vehicle and the engine control module (ECM). If it doesn't communicate, troubleshoot the DLC circuit.
4. Start the engine. Hold the engine speed at 3,000 rpm with no load (in neutral) until the radiator fan comes on, then let it idle.
5. Check the idle speed.
6. Jump the SCS line with the HDS.




7. Free the service loop (A) from the engine wire harness, then connect the timing light to the service loop.




8. Aim the light toward the pointer (A). Check the ignition timing under a no load condition (headlights, blower fan, 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 if it does not have the latest software, or substitute a known-good ECM, then recheck. If the system works properly, and the ECM was substituted, replace the original ECM.

10. Turn the ignition switch to LOCK (0).
11. Disconnect the HDS and the timing light.
12. Secure the service loop to the engine wire harness with wire ties.