Torque Management Feedback Signal Low
The P2639 code indicates that the Powertrain Control Module (PCM) has detected a low voltage condition in the torque management feedback signal circuit. This signal is used by the PCM to monitor the actual torque output of the engine and adjust ignition timing, fuel delivery, and transmission shift points accordingly. A low signal can result from a faulty torque sensor, wiring issues, or a malfunctioning PCM, leading to reduced engine performance and potential drivability concerns.
01. Most Common Causes
- Faulty torque sensor
- Open or shorted wiring in the torque management feedback circuit
- Poor electrical connection at the sensor or PCM
- Malfunctioning PCM
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or hesitation
- Harsh or delayed transmission shifts
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Visually inspect the torque sensor and wiring for damage or corrosion.
Step 3: Test the torque sensor signal voltage with a multimeter; compare to manufacturer specs.
Step 4: Check for continuity and shorts in the wiring between the sensor and PCM.
Step 5: If all else is fine, replace the torque sensor or PCM as needed.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as reduced engine power and transmission issues can lead to unsafe driving conditions. Have the vehicle inspected promptly.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Repair costs vary: a torque sensor replacement can be $100-$300, while PCM replacement may exceed $500.