B1727: Left Rear Seat Up Switch Short to Battery
The B1727 code indicates a short to battery voltage in the left rear seat up switch circuit. The seat control module detects excessive or continuous voltage on the signal line when the switch is not being pressed. This fault is defined under SAE J2012 body code standards and is manufacturer-specific for power seat systems.
1. Commonly Affected Makes
2. Most Common Causes
- Left rear seat adjuster switch stuck in the up position or internal failure
- Short to voltage in the seat switch wiring harness
- Moisture or corrosion in the switch or control module connector causing an electrical bridge
- Faulty seat control module
3. Symptoms You Will Notice
- Left rear seat moves up continuously or intermittently without switch input
- Seat position memory or adjustment functions inoperative
4. Step-by-Step Diagnosis
Check for any obvious damage or corrosion at the left rear seat switch connector and wiring
Test the up switch circuit for voltage with the switch released; should be near 0V
Inspect the wiring harness for shorts to battery voltage
If wiring and switch are OK, test or replace the seat control module
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but the seat may move unexpectedly, which could be a distraction. Have it repaired soon.
How much does it cost to fix?▼
Typical repair costs range from $100 to $400, depending on whether the switch, wiring, or control module needs replacement.