What Does B1989 Mean?
This code indicates that the Body Control Module (BCM) has detected a short to battery voltage in the pedal position rearward switch circuit. This switch is typically part of an adjustable pedal assembly system that monitors the rearward position of the brake or accelerator pedal mechanism. The BCM has identified that the signal wire is receiving constant battery voltage instead of the expected ground or variable signal, indicating a wiring fault or switch malfunction.
Common Causes
45%
Damaged or chafed wiring harness causing short to power wire in pedal position switch circuit
30%
Failed pedal position rearward switch with internal short to power
15%
Corroded or damaged connector terminals creating cross-circuit short at pedal switch
10%
BCM internal fault causing false short detection or internal circuit damage
Diagnostic Steps
1
Step 1: Perform visual inspection of the adjustable pedal assembly and wiring harness from the pedal position rearward switch to the BCM, looking for chafed insulation, pinched wires, or damaged connectors where wiring may contact power sources
2
Step 2: Disconnect the pedal position rearward switch connector and use a digital multimeter to measure voltage at the switch side connector signal wire with ignition on; reading should show 0 volts (no power present at switch)
3
Step 3: With switch disconnected, measure resistance between the BCM-side signal wire and battery positive; reading should show infinite resistance (open circuit). If continuity exists, trace and repair the short to power in the harness
4
Step 4: If harness tests good, reconnect the switch and backprobe the signal wire while moving the pedal through its range; voltage should vary between ground and 5V reference (not constant battery voltage). Replace switch if readings are incorrect
5
Step 5: Clear codes and perform functional test of adjustable pedal system through full range of motion while monitoring live data for proper switch operation and verify code does not return
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected a short to battery voltage in the pedal position rearward switch circuit. This switch is typically part of an adjustable pedal assembly system that monitors the rearward position of the brake or accelerator pedal mechanism. The BCM ...
The most common cause of B1989 (Pedal Position Rearward Switch Circuit Short to Battery) is: Damaged or chafed wiring harness causing short to power wire in pedal position switch circuit
Typical repair costs for B1989 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is generally safe to drive, but adjustable pedal functionality may be disabled or stuck in one position, which could create an uncomfortable or unsafe driving position for some drivers. Repair should be completed within a few days to restore proper pedal positioning capability.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1989 to identify the root cause.
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Quick Info
Category
Body
System
Adjustable Pedal Position System
Difficulty
Type
Manufacturer
Recommended Tools
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