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.
DTC 54: Fail-Safe Relay Malfunction
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Clear the DTC with the HDS.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Test-drive the vehicle at 19 mph (30 km/h) or more.NOTE: Drive the vehicle on the road, not on a lift.
- Check for DTCs with the HDS.
Is DTC 54 indicated?
YES - Go to step 6.
NO - Intermittent failure, the system is OK at this time. Refer to INTERMITTENT FAILURES TROUBLESHOOTING .
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Check the No. 2-3 (30 A) fuse in the under-hood fuse/relay box.
Is the fuse blown?
YES - Go to step 8.
NO - Reinstall the checked fuse, then go to step 16.
- Disconnect the VSA modulator-control unit 47P connector (see step 5).
- Check for continuity between VSA modulator-control unit 47P connector terminal No. 32 and body ground.Fig 1: Checking Continuity Between VSA Modulator-Control Unit 47P Connector Terminal No. 32 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES - Repair a short to body ground in the wire between the No. 2-3 (30 A) fuse in the under-hood fuse/relay box and the VSA modulator-control unit.
NO - Install a new No. 2-3 (30 A) fuse in the under-hood fuse/relay box, then go to step 10.
- Reconnect the VSA modulator-control unit 47P connector.
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Clear the DTC with the HDS.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Test-drive the vehicle at 19 mph (30 km/h) or more.NOTE: Drive the vehicle on the road, not on a lift.
- Check for DTCs with the HDS.
Is DTC 54 indicated?
YES - Go to step 19.
NO - Troubleshooting is complete.
- Disconnect the VSA modulator-control unit 47P connector (see step 5).
- Measure the voltage between VSA modulator-control unit 47P connector terminal No. 32 and body ground.Fig 2: Measuring Voltage Between VSA Modulator-Control Unit 47P Connector Terminal No. 32 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES - Go to step 18.
NO - Repair an open in the wire between the No. 2-3 (30 A) fuse in the under-hood fuse/relay box and the VSA modulator-control unit.
- Reconnect the VSA modulator-control unit 47P connector.
- Update the VSA modulator-control unit if it does not have the latest software (see VSA MODULATOR-CONTROL UNIT UPDATE ).
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Test-drive the vehicle at 19 mph (30 km/h) or more.NOTE: Drive the vehicle on the road, not on a lift.
- Check for DTCs with the HDS.
Is DTC 54 indicated?
YES - Check for loose terminals in the VSA modulator-control unit 47P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
NO - If the VSA modulator-control unit was updated, troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCS TROUBLESHOOTING .
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.