What Does B2479 Mean?
This code indicates the Body Control Module (BCM) has detected an abnormal short-to-ground condition in the parking brake switch circuit. The parking brake switch signals the vehicle's computer system when the parking brake is engaged or disengaged. A short to ground means the circuit voltage is being pulled to zero volts through an unintended path to chassis ground, preventing proper switch operation and signal transmission.
Common Causes
40%
Damaged or chafed wiring harness causing wire insulation failure and direct ground contact
30%
Faulty parking brake switch with internal short to ground
20%
Corroded or moisture-damaged connector terminals at parking brake switch creating ground path
10%
Body Control Module internal circuit failure causing false ground detection
Diagnostic Steps
1
Step 1: Perform visual inspection of parking brake switch location and wiring harness from switch to BCM, looking for visible damage, chafing against metal surfaces, pinched wires, or corrosion at connectors
2
Step 2: Disconnect the parking brake switch connector and measure resistance from the switch signal wire terminal (harness side) to chassis ground using a digital multimeter - should read infinite resistance (open circuit) if wiring is intact
3
Step 3: If wiring tests good, measure resistance across parking brake switch terminals with switch disconnected - typical reading should be open circuit when released and low resistance (less than 5 ohms) when engaged, infinite resistance to ground on all terminals indicates need for switch replacement
4
Step 4: If wiring shows continuity to ground, trace the affected wire along its routing path, inspecting for damaged insulation, pinch points near mounting brackets, and damaged grommets where harness passes through body panels
5
Step 5: Repair or replace damaged wiring/connectors as needed, reconnect all components, clear codes and verify parking brake warning light operates correctly on dash with brake engagement and disengagement
6
Step 6: Test drive vehicle and monitor for code return using scan tool live data to confirm parking brake switch signal changes properly between engaged and disengaged states
Estimated Repair Cost
$75 - $400
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an abnormal short-to-ground condition in the parking brake switch circuit. The parking brake switch signals the vehicle's computer system when the parking brake is engaged or disengaged. A short to ground means the circuit voltage is bei...
The most common cause of B2479 (BRAKE PARK SWITCH CIRCUIT SHORT TO GROUND) is: Damaged or chafed wiring harness causing wire insulation failure and direct ground contact
Typical repair costs for B2479 range from $75 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive, but the parking brake warning light may not function properly, potentially allowing you to drive with parking brake engaged or failing to alert you when brake is set. Repair within a few days to maintain proper parking brake operation and warning system functionality.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2479 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Parking Brake System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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