Ignition Timing Inspection

Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
Turn the ignition switch ON (II).
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 (see DLC CIRCUIT TROUBLESHOOTING ).
Check for DTCs (see GENERAL TROUBLESHOOTING INFORMATION ). If a DTC is present, diagnose and repair the cause before continuing with this test.
Start the engine. Hold the engine speed at 3,000 rpm with no load (in the N or P position) until the radiator fan comes on, then let it idle.
Check the idle speed (see IDLE SPEED INSPECTION ).
Jump the SCS line with the HDS.
Free the service loop from the wire harness, then connect the timing light to the service loop.

Fig 1: Connecting Timing Light To Service Loop
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Aim the light toward the pointer (A) on the cam chain case. Check the ignition timing under a no load condition (headlights, blower fan, rear window defogger, and air conditioner are turned off).
Ignition Tinning

M/T: 8° ± 2° BTDC (RED mark (B)) at idle in the Neutral

A/T: 8° ± 2° BTDC (RED mark (B)) at idle in the N or P position

Fig 2: Identifying Aim Light Pointer On Cam Chain Case
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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 (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the system works properly, and the ECM/PCM was substituted, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
Disconnect the HDS and the timing light.