Throttle/Pedal Pos Sensor/Switch B / C Voltage Correlation
P2137 indicates the engine control module has detected a voltage mismatch or correlation failure between the throttle position sensor and accelerator pedal position sensor. This code sets when these two sensors send conflicting signals, preventing proper engine throttle control.
What You Might Notice
- Engine stalling at stops or idle
- Complete loss of engine power or acceleration
- Sudden power loss while cruising at steady speeds
- Throttle stuck at current RPM without response
- Check engine light illuminated
Most Common Causes
- 1
Faulty accelerator pedal position sensor
The pedal sensor may be failing, sending incorrect voltage signals to the ECM. This is one of the most common causes of voltage correlation failures.
- 2
Defective throttle position sensor
A failing throttle sensor can send voltage readings that don't match the pedal input, triggering the correlation code.
- 3
Wiring issues or connector corrosion
Corroded connectors, loose connections, or damaged wiring between the sensors and ECM can cause voltage signal problems and sensor correlation failures.
- 4
Engine control module software issue
In rare cases, an ECM software glitch or corrupted calibration may cause false correlation failures even with functioning sensors.
How to Diagnose It
- 1
Check Faulty accelerator pedal position sensor — The pedal sensor may be failing, sending incorrect voltage signals to the ECM. This is one of the most common causes of voltage correlation failures.
- 2
Check Defective throttle position sensor — A failing throttle sensor can send voltage readings that don't match the pedal input, triggering the correlation code.
- 3
Check Wiring issues or connector corrosion — Corroded connectors, loose connections, or damaged wiring between the sensors and ECM can cause voltage signal problems and sensor correlation failures.
- 4
Check Engine control module software issue — In rare cases, an ECM software glitch or corrupted calibration may cause false correlation failures even with functioning sensors.
How to Fix It
- 1
Inspect and clean sensor connectors
Check both the throttle position sensor and accelerator pedal position sensor connectors for corrosion, looseness, or damage. Clean connectors thoroughly with electrical contact cleaner and ensure secure connections.
- 2
Test accelerator pedal position sensor voltage
Using a multimeter, verify the accelerator pedal sensor outputs correct voltage across its full range of motion. Compare readings to manufacturer specifications and replace the sensor if voltage is erratic or out of range.
- 3
Test throttle position sensor voltage
Measure throttle sensor output voltage throughout its operating range with a multimeter. Replace the sensor if voltage doesn't match specifications or fluctuates irregularly.
- 4
Check wiring harness for damage
Inspect the wiring harness between the sensors and ECM for cuts, pinches, fraying, or corrosion. Repair or replace damaged wiring segments as needed. If correlation persists after sensor replacement, reprogram or replace the ECM.
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