Ignition System: Testing and Inspection
Ignition Coil Relay Circuit Troubleshooting1. Check the No. 2 (15 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?
YES - Reinstall the fuse, then go to step 2.
NO - Replace the fuse. If the fuse continues to blow, locate and repair the short in the circuit between the driver's under-dash fuse/relay box and ignition coils.
2. Remove the ignition coil relay from the driver's 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 driver's under-dash fuse/relay box.
4. Check for continuity between ignition coil relay 4P socket terminal No. 2 and No. 1 ignition coil 3P connector terminal No. 3.
Is there continuity?
YES - Go to step 5.
NO - Repair 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).
6. Turn the ignition switch ON (II).
7. Make sure the HDS communicates with the vehicle and the powertrain control module (PCM). If it doesn't communicate, troubleshoot the DLC circuit.
8. Jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the PCM from damage.
9. Disconnect PCM connector A (49P).
10. Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.
Is there continuity?
YES - Repair short in the wire between ignition coil relay 4P socket terminal No. 3 and the PCM (A6).
NO - Go to step 11.
11. Check for continuity between ignition coil relay 4P socket terminal No. 3 and PCM connector terminal A6.
Is there continuity?
YES - The system is OK at this time. Check for loose or poor connections at the ignition coil relay and the PCM (A6).
NO - Repair open in the wire between ignition coil relay 4P socket terminal No. 3 and the PCM (A6).