B1507 Flash-to-Pass Switch Circuit Malfunction
The B1507 code indicates a fault in the flash-to-pass (FTP) switch circuit, which is used to momentarily flash the high beams without latching the turn signal stalk. The body control module (BCM) or lighting module monitors this circuit and has detected an electrical anomaly, such as out-of-range voltage, an open circuit, or a short circuit. This prevents the high-beam flash signal from being processed correctly, affecting the vehicle's ability to alert other drivers.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or internally worn multifunction switch (turn signal stalk)
- Short to ground or voltage in the FTP circuit wiring
- Open circuits or loose, corroded connectors in the steering column
- Defective body control module (BCM) – rare but possible
- Blown lighting circuit fuse
3. Symptoms You Will Notice
- Flash-to-pass function does not work
- High beams may not operate properly
4. Step-by-Step Diagnosis
Check the lighting circuit fuse for the flash-to-pass function
Inspect the multifunction switch and its connector for damage or corrosion
Test the FTP switch circuit for continuity, shorts, and proper voltage
Verify BCM operation and reprogram if necessary
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but the flash-to-pass feature will be inoperative, which may reduce your ability to alert other drivers in certain situations.
How much does it cost to fix?▼
Repair costs typically range from $100 to $300, depending on whether the multifunction switch needs replacement and labor rates.