DTC P0351: Intake Side Ignition Coil Power Circuit Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0351 indicated?

YES -Go to step 4.

NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse, the intake side ignition coil, and the PCM.
Turn the ignition switch to LOCK (0).
Check the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse in the auxiliary under-hood fuse/relay box.
Is the fuse OK?

YES -Go to step 11.

NO -Go to step 6.
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Remove the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse from the auxiliary under-hood fuse/relay box.
Check for continuity between PCM connector terminal B41 and body ground.

Fig 1: Checking Continuity Between PCM Connector Terminal B41 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 10.

NO -Go to step 24.
Continue to check for continuity between PCM connector terminal B41 and body ground while disconnecting the 3P connector from each intake side ignition coil, one at time.
Did any ignition coil cause an open when it was disconnected?

YES -Replace the ignition coil that caused an open when it was disconnected, then go to step 18.

NO -Repair a short in the wire between the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse, the intake side ignition coil, and the PCM (B41), then go to step 18.
Jump the SCS line with the HDS.
Disconnect PCM connector B (49P).
Turn the ignition switch to ON (II).
Measure the voltage between PCM connector terminal B41 and body ground.

Fig 2: Measuring Voltage Between PCM Connector Terminal B41 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 23.

NO -Go to step 15.
Turn the ignition switch to LOCK (0).
Open the fuse access panel (A), then test the ignition coil relay (B) in the under-dash fuse/relay box. (see POWER RELAY TEST ).

Fig 3: Identifying Fuse Access Panel And Ignition Coil Relay
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is the ignition coil relay OK?

YES -Repair an open in the wire between the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse and the PCM (B41). If the wire is OK, replace the auxiliary under-hood fuse/relay box (see CONNECTOR TO FUSE/RELAY BOX INDEX ), then go to step 17.

NO -Replace the ignition coil relay, then go to step 17.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Turn the ignition switch to ON (II).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0351 indicated?

YES -Check for poor connections or loose terminals at the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse, the intake side ignition coil, and the PCM, then go to step 1.

NO -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC'S TROUBLESHOOTING .
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0351 indicated?

YES -Check for poor connections or loose terminals at the No. 1 INTAKE SIDE IGNITION COILS (15A) fuse, the intake side ignition coil, and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step 1.

NO -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC'S TROUBLESHOOTING .