What Does B1990 Mean?
This code indicates a malfunction in the feedback circuit of a potentiometer used to detect the forward/rearward position of an adjustable pedal assembly. The Body Control Module (BCM) or seat control module has detected that the voltage signal from the position sensor is out of range, erratic, or not correlating properly with commanded position. This affects power-adjustable pedal systems that allow drivers to electrically move the brake and accelerator pedals closer or farther away.
Common Causes
45%
Faulty pedal position potentiometer or sensor internal failure
30%
Damaged wiring harness, broken wires, or corroded connector at pedal actuator
15%
Poor ground connection at pedal assembly or control module
10%
Failed pedal adjustment motor or actuator causing mechanical binding affecting sensor
Diagnostic Steps
1
Step 1: Visually inspect the adjustable pedal assembly wiring harness and connectors for damage, corrosion, or loose connections. Check for bent pins, moisture intrusion, or chafing against sharp edges.
2
Step 2: With ignition on, use a multimeter to measure the reference voltage (typically 5V) and ground at the potentiometer connector. Verify voltage is within specification (4.5-5.5V) and ground has less than 0.1V resistance to battery negative.
3
Step 3: Backprobe the signal wire at the potentiometer while commanding pedal movement through scan tool bi-directional controls. Signal voltage should sweep smoothly from approximately 0.5V to 4.5V without dropouts or erratic spikes.
4
Step 4: If voltage readings are correct but code persists, disconnect the potentiometer and measure its resistance while manually moving the pedal mechanism. Resistance should change smoothly across the full range without intermittent open circuits.
5
Step 5: Check ground continuity from the pedal assembly mounting bracket to battery negative (should be less than 1 ohm). Verify all mounting bolts are tight and making proper metal-to-metal contact.
6
Step 6: After repairs, clear codes, perform pedal calibration procedure per manufacturer specifications, cycle pedal through full range multiple times, and road test to verify proper operation and no code return.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates a malfunction in the feedback circuit of a potentiometer used to detect the forward/rearward position of an adjustable pedal assembly. The Body Control Module (BCM) or seat control module has detected that the voltage signal from the position sensor is out of range, erratic, or n...
The most common cause of B1990 (Pedal Forward / Rearward Potentiometer Feedback Circuit Failure) is: Faulty pedal position potentiometer or sensor internal failure
Typical repair costs for B1990 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle remains safe to drive as brake and accelerator pedals will still function normally in their current position, but adjustable pedal feature will be disabled. Repair within a reasonable timeframe to restore comfort and convenience features, especially if multiple drivers use the vehicle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1990 to identify the root cause.
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Quick Info
Category
Body
System
Body Comfort/Convenience Systems
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