LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2009 >> CSX Base, Automatic >> Repair and Diagnosis >> Engine Performance >> Tune-Up >> Ignition System >> Ignition Coil Relay Circuit Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Ignition Coil Relay Circuit Troubleshooting

  1. Check the No. 18(15 A) fuse in the under-hood 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-hood fuse/relay box and test it (see POWER RELAY TEST ).

    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. 2 and body ground, then terminal No. 4 and body ground.
    Fig 1: Measuring Voltage Between Ignition Coil Relay 4P Socket Terminal 2 And Body Ground
    G06265424Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 4.

    NO  -Replace the under-hood 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.
    Fig 2: Checking Continuity Between Ignition Coil Relay 4P Socket Terminal 2 And 1 Ignition Coil 3P Connector Terminal 3
    G06265425Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 5.

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

  5. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on GENERAL TROUBLESHOOTING INFORMATION ).
  6. Turn the ignition switch ON (II).
  7. Make sure the HDS communicates with the vehicle and the engine control module (ECM)/powertrain control module (PCM). If it doesn't, troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).
  8. Jump the SCS line with the HDS, then turn the ignition switch OFF.
    NOTE: This step must be done to protect the ECM/ PCM from damage.
  9. Disconnect ECM/PCM connector A (44P).
  10. Check for continuity between ignition coil relay 4P socket terminal No. 3 and body ground.
    Fig 3: Checking Continuity Between Ignition Coil Relay 4P Socket Terminal 3 And Body Ground
    G06265426Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair short in the wire between ignition coil relay 4P socket terminal No. 3 and ECM/PCM (A6).

    NO  -Go to step 11.

  11. Check for continuity between ignition coil relay 4P socket terminal No. 3 and ECM/PCM connector terminal A6.
    Fig 4: Checking Continuity Between Ignition Coil Relay 4P Socket Terminal 3 And ECM/PCM Connector Terminal A6
    G06265427Courtesy of AMERICAN HONDA MOTOR CO., INC.

    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 (A6).

    NO  -Repair open in the wire between ignition coil relay 4P socket terminal No. 3 and the ECM/PCM (A6).