Ignition System: Testing and Inspection

Ignition Coil Relay Circuit Troubleshooting

1. Check the No. 2 (15 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES - Go to step 2.

NO - Replace the fuse

2. Remove the ignition coil relay from the under-dash fuse/relay box, and test it.

Is the relay OK?

YES - Go to step 3.

NO - Replace the ignition coil relay.




3. Measure the voltage between ignition coil relay 4P socket terminal No. 1 and body ground, then terminal No. 4 and body ground.

Is there battery voltage?

YES - Go to step 4.

NO - Replace the under-dash fuse/relay box.




4. Check for continuity between ignition coil relay 4P socket terminal No. 2 and the No. 1 ignition coil 3P connector terminal No. 3.

Is there continuity?

YES - Go to step 5.

NO - Repair an open in the wire between ignition coil relay 4P socket terminal No. 2 and No. 1 ignition coil 3P connector terminal No. 3.

5. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC). Turn the ignition switch ON (II), and jump the SCS line with the HDS, then turn the ignition switch OFF.

NOTE: This step must be done to protect the engine control module (ECM)/powertrain control module (PCM) from damage.

6. Disconnect ECM/PCM connector E (31P) (2004-2005 models) or PCM connector A (31P) (2006 model).




7. Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.

Is there continuity?

YES - Repair a short in the wire between ignition coil relay 4P socket terminal No. 3 and the ECM/PCM (E20 (2004-2005 models) or A20 (2006 model)).

NO - Go to step 8.




8. Check for continuity between ignition coil relay 4P socket terminal No. 3 and ECM/PCM connector terminal E20 (2004-2005 models) or A20 (2006 model).

Is there continuity?

YES - The system is OK at this time. Check for loose or poor connections at the ignition coil relay and the ECM/PCM (E20 (2004-2005 models) or A20 (2006 model)).

NO - Repair an open in the wire between ignition coil relay 4P socket terminal No. 3 and the ECM/PCM (E20 (2004-2005 models) or A20 (2006 model)).