Ignition Coil Relay Circuit Troubleshooting

Check the No. 2 (15 A) fuse in the underdash fuse/relay box.
Is the fuse OK?
1. YES - Go to step 2.
2. NO - Replace the fuse.
Remove the ignition coil relay from the underdash fuse/relay box, and test it (see POWER RELAY TEST ).
Is the relay OK?
1. YES - Go to step 3.
2. NO - Replace the ignition coil relay.
Measure the voltage between ignition coil relay 4P socket terminal No. 1 and body ground, then terminal No. 4 and body ground.

Fig 1: Measuring Voltage Between Ignition Coil Relay 4P Socket Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 4.
2. NO - Replace the underdash fuse/relay box.
Check for continuity between ignition coil relay 4P socket terminal No. 2 and the No. 1 ignition coil 3P connector terminal No. 3.

Fig 2: Checking For Continuity Between Ignition Coil Relay 4P Socket Terminal No. 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 5.
2. 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.
Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
Turn the ignition switch OFF.
Jump the SCS line with the HDS.
NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
Disconnect PCM connector A (44P).
Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.

Fig 3: Checking For Continuity Between Ignition Coil Relay 4P Socket Terminal No. 3 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair a short in the wire between ignition coil relay 4P socket terminal No. 3 and the PCM (A6).
2. NO - Go to step 10.
Check for continuity between ignition coil relay 4P socket terminal No. 3 and PCM connector terminal A6.

Fig 4: Checking For Continuity Between Ignition Coil Relay 4P Socket Terminal No. 3 And PCM Connector Terminal A6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - The system is OK at this time. Check for loose or poor connections at the ignition coil relay and the PCM (A6).
2. NO - Repair an open in the wire between ignition coil relay 4P socket terminal No. 3 and the PCM (A6).