Power Door Memory Lock Relay Circuit Failure
Diagnostic trouble code B1392 indicates a fault in the power door glass memory lock relay circuit. This relay is part of the vehicle's access/body control module (GEM or BCM on Ford vehicles) and manages the automatic locking function for power windows with position memory. The module detects an electrical anomaly in the relay circuit, such as an open circuit, short to ground, or short to battery voltage, preventing the window memory system from operating correctly.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or damaged power door memory lock relay
- Short to ground, short to battery, or open circuit in the relay wiring
- Corroded, oxidized, or loose connectors in the wiring harness
- Blown fuse in the relay control circuit
3. Symptoms You Will Notice
- Power windows with memory function do not operate automatically
- Memory position recall for windows is inoperative
- Possible illumination of the check engine or warning light
4. Step-by-Step Diagnosis
Scan for codes and verify B1392 is present
Inspect the memory lock relay and its wiring for damage, corrosion, or loose connections
Check the fuse for the relay control circuit and replace if blown
Test the relay operation using a multimeter or substitute a known good relay
If wiring and relay are okay, test the GEM/BCM for proper output; replace if faulty
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive, but the power window memory function will not work. The vehicle remains drivable.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the issue is a simple relay or fuse replacement versus a more expensive module replacement.