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 81: ABS Modulator-control Unit Internal Circuit Malfunction
- Turn the ignition switch to ON (II).
- Check for other system DTCs.
Is another DTC indicated?
YES -Do the appropriate troubleshooting for the DTC.
NO -Go to step 3.
- Clear the DTC with the HDS.
- Turn the ignition switch to LOCK (0).
- Test-drive the vehicle at 19mph (30 km/h) or more.NOTE: Drive the vehicle on the road, not on a lift.
- Check for DTCs with the HDS.
Is DTC 81 indicated?
YES -Check for loose terminals in the ABS modulator-control unit 47P connector. If necessary, substitute a known-good ABS modulator-control unit (see ABS MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ), and retest.
NO -Intermittent failure, the system is OK at this time.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.