B1374: Illuminated Entry Relay Short to Ground
Code B1374 indicates that the body control module (BCM) has detected a short to ground in the control circuit of the illuminated entry relay. This relay powers the courtesy lights, entry lights, and sometimes the glove box light when the vehicle is unlocked or a door is opened. The BCM monitors the control circuit voltage and triggers this code when the voltage drops below the expected threshold, suggesting an unintended path to ground. The issue is typically present when the circuit is open or inactive, and the module checks for a reference voltage to verify wiring integrity.
1. Commonly Affected Makes
2. Most Common Causes
- Wiring in the illuminated entry relay circuit shorted to ground
- Faulty illuminated entry relay with internal short
- Corroded or damaged electrical connections at the BCM harness
- Internally damaged body control module (BCM)
- Chafed or worn wiring harness passing through door hinges
3. Symptoms You Will Notice
- Courtesy lights stay on continuously or fail to turn on
- Entry lights (door handle, puddle lights) malfunction
- Glove box light may not operate
- Battery drain due to lights staying on
4. Step-by-Step Diagnosis
Scan for additional codes and note freeze frame data
Visually inspect the illuminated entry relay and its wiring for damage, corrosion, or chafing
Test the relay control circuit for continuity to ground with the relay disconnected
Check for voltage at the relay control pin from the BCM; if missing, suspect BCM or wiring issue
If wiring and relay check out, test the BCM output or replace the BCM as a last resort
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but you may experience battery drain or non-functional courtesy lights. It's recommended to diagnose and repair promptly to avoid a dead battery.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the issue is a simple wiring repair or requires BCM replacement.