B1486: Brake Pedal Position Switch Short to Ground
The B1486 code indicates that the Powertrain Control Module (PCM) or Body Control Module (BCM/GEM) has detected a short to ground in the brake pedal position (BPP) switch signal circuit. This prevents the module from accurately reading the pedal position, affecting systems such as brake lights, cruise control, shift interlock, and keyless start.
1. Commonly Affected Makes
2. Most Common Causes
- Internal short to ground in the brake pedal position switch
- BPP signal circuit wiring chafed or pinched against chassis/body
- Damaged, corroded, or grounded terminals at the BPP switch connector
- Internal fault in the PCM/BCM/GEM input driver
3. Symptoms You Will Notice
- Brake lights stay on or fail to illuminate
- Cruise control inoperative
- Shift interlock malfunction (cannot shift out of Park)
- Keyless start system failure
4. Step-by-Step Diagnosis
Scan for codes and verify B1486 is present
Inspect BPP switch connector for damage, corrosion, or bent pins
Check for continuity to ground on the BPP signal wire; if shorted, repair wiring
Test BPP switch operation with a multimeter; replace if internally shorted
If wiring and switch are good, suspect PCM/BCM fault and perform module tests
5. Frequently Asked Questions
Is it safe to drive?▼
No, driving with this code is not recommended because brake light function may be compromised, increasing the risk of rear-end collisions. Additionally, cruise control and shift interlock may not work properly.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch needs replacement ($50–$150) or wiring repair is required ($100–$300). Module replacement can exceed $500.