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.
Check Power Supply And Ground Circuit Of Backup Unit
- CHECK FUSE AND RELAY
.
- Turn the ignition switch to OFF.
- Check the fuse on the upstream of the backup unit. Ref. to SECURITY AND LOCKS>RELAY AND FUSE>INSPECTION .
Is the check result OK?
Yes: Go to 2.
No: Replace the defective fuse.
- CHECK POWER SUPPLY
.
- Disconnect the backup unit connector.
- Turn the ignition switch to ON.
- Measure the voltage between backup unit connector and chassis ground.
Connector & terminal
(AD33) No. 3 (+) - Chassis ground (-):
(AD33) No. 5 (+) - Chassis ground (-):
(AD33) No. 8 (+) - Chassis ground (-):
Is the voltage 9 V or more?
Yes: Go to 3.
No: Check the harness for open or short circuit between the backup unit and the fuse.
- CHECK GROUND CIRCUIT
.
Measure the resistance between backup unit connector and chassis ground.
Connector & terminal
(AD33) No. 6 - Chassis ground:
Is the resistance less than 10 Ω?
Yes: The power supply and ground circuit are OK.
No: Repair or replace the harness.
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.