B1241: Rear Washer Pump Relay Short to Battery
The body control module (BCM) has detected a short to battery voltage (B+) on the control circuit for the rear washer pump relay. This means the relay command line is stuck at battery voltage when the BCM tries to turn it off (low side), preventing proper control of the rear washer system and potentially causing the pump to run continuously.
1. Commonly Affected Makes
2. Most Common Causes
- Rear washer pump relay with internal short (coil or contacts)
- Control circuit wiring shorted to battery power (B+)
- Damaged, corroded, or moisture-contaminated connectors in the relay circuit
- Failed output driver inside the BCM or integration relay
3. Symptoms You Will Notice
- Rear washer pump runs continuously even with key off
- Rear washer does not operate when commanded
- Blown fuse for rear washer circuit
4. Step-by-Step Diagnosis
Check for battery voltage on the relay control wire with key off; if present, locate short to B+.
Inspect relay and connectors for corrosion, damage, or moisture.
Test relay operation: apply ground to control terminal; if pump runs, relay is likely good.
If wiring and relay are okay, suspect faulty BCM output driver.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the rear washer may not work or the pump may run continuously, which can drain the battery. Repair is recommended soon.
How much does it cost to fix?▼
Typically $100–$300 for diagnosis and repair, depending on whether the relay, wiring, or BCM needs replacement.