Pedal Position Sensor Feedback Circuit Malfunction
Code B1990 indicates an electrical fault in the pedal position sensor feedback circuit, specifically for forward/rearward movement. This sensor monitors the physical position of the accelerator pedal and sends a proportional voltage signal to the throttle body control unit or engine control module (ECM). When the module detects that the feedback circuit voltage is out of normal range, invalid, or has lost continuity, this diagnostic trouble code is set.
1. Commonly Affected Makes
2. Most Common Causes
- Damaged or worn internal pedal position sensor (accelerator pedal position sensor)
- Short to ground or voltage in the feedback circuit wiring
- Open circuit or high resistance in pedal wiring or connectors
- Bent, corroded, or poorly connected sensor connector pins
- Faulty engine control module (ECM) or throttle body control module
3. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Unresponsive or erratic accelerator pedal
- Poor acceleration or hesitation
4. Step-by-Step Diagnosis
Scan for additional codes and freeze frame data
Visually inspect pedal sensor connector and wiring for damage or corrosion
Test pedal sensor voltage and resistance per manufacturer specifications
Check for shorts or opens in the feedback circuit using a multimeter
If wiring and sensor are okay, test ECM/throttle body module operation
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. This fault can cause sudden loss of throttle control or unintended acceleration, posing a serious safety risk. Have the vehicle towed to a repair shop.
How much does it cost to fix?▼
Repair costs typically range from $200 to $600, depending on whether the pedal sensor ($100-$300) or the ECM ($400-$800) needs replacement, plus labor.