Accessory Delay Relay Circuit Short to Battery
The Body Control Module (BCM) or Generic Electronic Module (GEM) has detected a short to battery voltage in the accessory delay relay output circuit. This fault indicates that the relay contacts are stuck closed (welded) or that the accessory power wiring (radio, power windows, sunroof) has a short to positive, keeping accessories powered even with the key off and doors closed.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty accessory delay relay with welded or stuck contacts
- Short to battery voltage in the relay output circuit (RAP circuit) wiring
- Internal BCM/GEM failure in the relay driver or monitoring circuit
- Corroded or loose connections in the central junction box (fuse/relay box)
3. Symptoms You Will Notice
- Accessories (radio, windows, sunroof) remain on after key is removed and doors are closed
- Battery drain or dead battery after vehicle sits
4. Step-by-Step Diagnosis
Check for battery drain with key off; measure parasitic draw.
Inspect accessory delay relay for welded contacts; test relay operation.
Check for short to battery in the RAP circuit wiring using a multimeter.
Inspect BCM/GEM for signs of damage or corrosion; test relay control signal.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but the battery may drain if accessories stay on. It's best to diagnose and repair promptly to avoid a dead battery.
How much does it cost to fix?▼
Typically $100–$300 for relay replacement; up to $500–$800 if BCM replacement is needed.