Right Reverse Lamp Circuit Short to Battery
The Body Control Module (BCM) or rear lighting module has detected a short to battery voltage (B+) in the control circuit for the right rear backup lamp. This means the signal or power wire for the bulb is making direct contact with a permanent or switched 12V source, causing the lamp to stay on continuously or the module to shut down the output driver to protect the circuit.
1. Commonly Affected Makes
2. Most Common Causes
- Chafed or pinched wiring for the right reverse light circuit contacting a B+ wire
- Corroded or bent pins inside the right rear bulb socket causing a short to positive
- Internal shorted output driver in the BCM or rear lighting module
- Improperly installed or damaged trailer hitch wiring harness
3. Symptoms You Will Notice
- Right reverse light stays on constantly
- Right reverse light does not work
- Blown fuse for reverse lights
- BCM or lighting module may disable the circuit
4. Step-by-Step Diagnosis
Check for aftermarket trailer wiring; disconnect and retest
Inspect right reverse bulb and socket for corrosion, bent pins, or wrong bulb type
Visually inspect wiring harness for chafing or pinching near the right rear area
Measure voltage at the bulb socket with the ignition on and reverse not engaged; should be 0V
If voltage is present, isolate the short by disconnecting the BCM or module and checking continuity to ground
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the reverse light may not function properly or may stay on, which can confuse other drivers. It's best to diagnose and repair soon.
How much does it cost to fix?▼
Typically $100–$300 for diagnosis and repair, depending on whether it's a simple bulb/socket issue or a wiring/module problem.