Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DLC Circuit Troubleshooting
- Make sure the HDS and its DLC cable are working properly.
- If the IMA battery level indicator displays no level, start the engine, and hold it between 3,500 and 4,000 rpm without load (in P or N) until the level in the indicator is half full.
- Turn the ignition switch to LOCK (0).
- Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
- Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -go to step 4.
NO -Do the DLC circuit troubleshooting (see DLC CIRCUIT TROUBLESHOOTING ).
- Check the No. 42 +B IMA 1 (10 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -go to step 5.
NO -Repair a short in the wire between the No. 42 +B IMA (10 A) fuse and the MCM (A1). Also replace the No. 42 +B IMA 1 (10 A) fuse.
- Turn the ignition switch to LOCK (0).
- Turn the battery module switch OFF (see DISCONNECTING THE MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR ).
- Remove the IPU cover (see IPU COVER REMOVAL/INSTALLATION ).
- Turn the battery module switch ON (see DISCONNECTING THE MOTOR POWER CABLE CONNECTOR FROM THE MOTOR STATOR ).
- Turn the ignition switch to ON (II), and listen for a clicking sound from MCM relay 1 (A).
Is there a clicking sound?
YES -go to step 10.
NO -go to step 25.
- Turn the ignition switch to LOCK (0).
- Remove MCM relay 1.
- Check MCM relay 1 (see
POWER RELAY TEST
).
Is the relay OK?
YES -go to step 13.
NO -Replace MCM relay 1.
- Turn the ignition switch to ON (II).
- Measure the voltage between MCM relay 1 4P connector terminal No. 2 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -go to step 15.
NO -Repair an open in the wire between the No. 42 + B IMA (10 A) fuse and MCM relay 1.
- Turn the ignition switch to LOCK (0).
- Reinstall MCM relay 1 (A).
- Remove the PCU lid, the PCU busplate, and the PCU cover (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
- Turn the ignition switch to ON (II).
- Measure the voltage between MCM connector terminals A1 and A4.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -go to step 20.
NO -go to step 24.
- Turn the ignition switch to LOCK (0).
- Disconnect MCM connector A (31P).
- Check for continuity between MCM connector terminal A30 and DLC terminal No. 6.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -go to step 23.
NO -Repair an open in the wire between DLC terminal No. 6 and the MCM (A30).
- Check for continuity between MCM connector terminal A31 and DLC terminal No. 14.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Update the MCM if it does not have the latest software (see MOTOR CONTROL MODULE (MCM) UPDATE ), or substitute a known-good MCM (see SUBSTITUTING THE MCM ), and recheck. If the symptom goes away with a known-good MCM, replace the original MCM (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
NO -Repair an open in the wire between DLC terminal No. 14 and the MCM(A31).
- Measure the voltage between MCM connector terminal No. 1 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Repair an open in the wire between the MCM (A4) and G901.
NO -Repair an open in the wire between the MCM (A4) and MCM relay 1.
- Turn the ignition switch to LOCK (0).
- Remove MCM relay 1.
- Check MCM relay 1 (see
POWER RELAY TEST
).
Is the relay OK?
YES -go to step 28.
NO -Replace MCM relay 1.
- Turn the ignition switch to ON (II).
- Measure the voltage between MCM relay 1 4P connector terminal No. 4 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -go to step 30.
NO -Repair an open in the wire between the No. 42 + B IMA (10 A) fuse and MCM relay 1.
- Turn the ignition switch to LOCK (0).
- Reinstall MCM relay 1 (A).
- Remove the PCU lid, the PCU busplate, and the PCU cover (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
- Turn the ignition switch to ON (II).
- Measure the voltage between MCM connector terminal A7 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -go to step 35.
NO -Repair an open in the wire between MCM relay 1 and the MCM (A7).
- Turn the ignition switch to LOCK (0).
- Disconnect MCM connector A (31P).
- Check for continuity between MCM connector terminal A4 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -go to step 38.
NO -Repair an open in the wire between the MCM (A4) and G901.
- Turn the ignition switch to ON (II).
- Measure the voltage between MCM connector terminal A3 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -go to step 40.
NO -Repair an open in the wire between the No. 22 METER (7.5 A) fuse and the MCM (A3).
- Measure the voltage between MCM connector terminal A2 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Update the MCM if it does not have the latest software (see MOTOR CONTROL MODULE (MCM) UPDATE ), or substitute a known-good MCM (see SUBSTITUTING THE MCM ), and recheck. If the symptom goes away with a known-good MCM, replace the original MCM (see MOTOR CONTROL MODULE (MCM) REMOVAL/INSTALLATION ).
NO -Repair an open in the wire between the No. 1 BACK UP (15 A) fuse and the MCM (A2).
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.