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 B0432: Rear Defogger Relay Circuit (Open Or Short To Ground): Description
When Body Control Module (BCM) receives a defogger on request from rear defogger switch with engine running, BCM will ground White wire to energize rear defogger relay. BCM monitors voltage level on rear defogger relay control circuit. When BCM activates rear defogger relay, voltage level in rear defogger relay control circuit should be low. When relay is not activated, voltage level in rear defogger relay control circuit should be high.
DTC B0432 will set when BCM detects a low voltage level in White wire for 2 seconds when it is not energizing rear defogger relay. No driver warning message will be displayed.
DTC B0432 requires an ignition cycle to change from current to history. If conditions for malfunction no longer exist, history DTC will clear after 50 consecutive ignition cycles. DTC B0432 will also clear when conditions no longer exist, and Instrument Panel Cluster (IPC) or scan tool is used to clear codes.
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.