Throttle/Pedal Position Sensor/Switch D/F Voltage Correlation
What does P2139 mean?
The P2139 code means the vehicle's onboard diagnostic system has detected: Throttle/Pedal Position Sensor/Switch D/F Voltage Correlation. This is a critical severity code.
Common Symptoms
- Reduced engine power
- Throttle does not match pedal input
- Delayed or inconsistent acceleration
- Limp mode active
- Check engine light on
Probable Causes (Ranked by Likelihood)
- APP sensor D output not matching TPS F output from throttle body Very High
- Carbon buildup on throttle body causing position error High
- Faulty electronic throttle body TPS Moderate
- Faulty accelerator pedal position sensor Moderate
- Wiring issue in either D or F circuit Low
Step-by-Step Diagnostic Procedure
-
Compare APP sensor D reading to TPS F reading with scan tool -- they should show consistent relationship
-
Clean throttle body to ensure TPS F reads accurately
-
Test APP sensor D by pressing pedal slowly -- signal should be smooth and consistent
-
Check both sensor connectors for corrosion or damage
-
If cleaning does not resolve, determine which sensor (pedal or throttle body) has the incorrect reading
Frequently Asked Questions
Can I drive with code P2139?
Only short distances. The PCM has detected a mismatch between pedal position and throttle body position, meaning the throttle is not going where the pedal tells it. The vehicle will have limited power.
Could this be a pedal problem or a throttle body problem?
It could be either. The D circuit is on the pedal and the F circuit is on the throttle body. You need to determine which sensor is reading incorrectly by comparing each to its companion sensor (D compared to E, and F compared to the primary TPS).
Why does the PCM compare pedal position to throttle position?
The PCM cross-references pedal position with actual throttle position to verify the electronic throttle system is working correctly. If the pedal says 50% but the throttle is only at 20%, something is wrong and the PCM limits power to prevent unsafe conditions.