B1436: Wiper Relay Coil Short to Battery
The B1436 code indicates that the body control module (GEM/BCM) has detected a short to battery positive (B+) in the relay coil circuit that controls the high and low speeds of the windshield wiper motor. This means there is unwanted continuity between the relay coil control wire and a positive power supply line, preventing proper relay switching or potentially keeping the relay permanently energized. As a result, the intermittent or variable speed operation of the wiper system is affected.
1. Commonly Affected Makes
2. Most Common Causes
- Short circuit in the relay coil wiring to battery positive (B+)
- Internal short circuit in the high/low speed wiper relay coil
- Faulty GEM/BCM module applying continuous voltage to the control circuit
- Damaged, corroded, or improperly spliced connectors or terminals causing contact with battery power
3. Symptoms You Will Notice
- Wipers operate only at high speed or run continuously
- Intermittent or variable speed wiper function not working
- Wipers may not turn off or respond to switch commands
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to wiper system or BCM
Inspect wiper relay and its wiring for signs of short to battery positive
Test relay coil resistance and verify no continuity to B+
Check GEM/BCM for proper output signals; replace if faulty
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the wipers may not function correctly, which could be unsafe in rain. It's best to repair promptly.
How much does it cost to fix?▼
Typically $100–$300, depending on whether it's a wiring repair, relay replacement, or BCM replacement.