DTC code
P2138
Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation
Technical guide
Symptoms
- Check engine light on
- loss or lack of engine power
- including sudden loss of power at cruise speed
- engine stalling
- especially when coming to a complete stop
- no acceleration response or throttle stuck
- possible unintended acceleration. Vehicle may enter reduced-power (limp) mode. Not recommended to drive with this code active due to the risk of sudden loss of throttle control.
Probable causes
- 1) Failed throttle position (TP) sensor or accelerator pedal position (APP) sensor. 2) Circuit problems: damaged
- chafed or corroded wiring
- faulty or corroded connectors in the TP/APP sensor circuits. 3) Damaged throttle body or throttle body motor. 4) Damaged accelerator pedal assembly wiring or sensors. 5) PCM/ECM fault (least common).
Diagnostic steps
- Scan for codes and record freeze frame data.
- Visually inspect the throttle body, throttle body motor and throttle position sensor for damage or contamination.
- Inspect wiring and connectors of both the TP sensor and APP sensor circuits for chafing, corrosion, loose pins or faulty connections.
- Test the throttle body motor and throttle position sensor following the manufacturer's recommended test procedure; compare the two sensor signals for correlation on live data.
- Test the accelerator pedal position sensor assembly the same way.
- If sensors and circuits pass, test the ECM/PCM operation.
- Clear codes and road test to confirm the repair.
Cross-checked technical synthesis (QA). It does not replace the manufacturer's procedure.
Models most reported with this code (NHTSA)
Count of distinct owner complaints mentioning the code. US data — same engines, same failures.
AI here is a librarian: this page shows only what mechanics confirmed, or says “unknown”. It never suggests a diagnosis — MECCANIC interprets the code, never your car.
0 confirmed cases on P2138
Nothing confirmed yet for this code. No guess is offered on purpose.
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