P2138 on Jeep: How to Diagnose & Fix
Throttle/Pedal Position Sensor D/E Voltage Correlation
1 Jeep model · 1 documented issue
P2138 on Jeep by model: symptoms, diagnosis and fix
The electronic-throttle-control warning lamp and reduced-power or limp mode are protective responses, not a diagnosis that the throttle body has failed. Depending on the stored DTC and application, the factory path may lead to a stuck or contaminated throttle plate, throttle motor or position-sensor response, accelerator-pedal sensors, a five-volt supply fault, damaged wiring or terminals, or a PCM issue. The old card's thermostat shopping claim is not part of the cited ETC diagnostic path, and a throttle body should not be ordered from the warning lamp alone.
Common Symptoms
- Electronic throttle control warning lamp
- Reduced engine output, limited RPM, or limp mode
- Poor or absent accelerator response
- One or more throttle, pedal, voltage-supply, or actuator DTCs
How to Fix
Before clearing anything, record every PCM DTC, pending code, freeze-frame value, battery voltage, temperature, and the exact conditions under which reduced power occurred. Diagnose prerequisite five-volt-supply, throttle-position, accelerator-pedal, or other active faults in the order specified by the current factory procedure for that VIN and engine. For a P2111-style fault, inspect the throttle plate for binding or foreign material and run the scan-tool throttle-follower test, then test the motor circuits, connector terminals, and wiring as directed. For a pedal-correlation code such as P2138, follow the accelerator-pedal sensor and circuit procedure instead. Replace and relearn a throttle body only when the applicable test condemns it; do not buy a thermostat as an ETC rule-out part.
Owner tips & cautions
- WarningAn ETC lamp does not prove the throttle body failed. Save the codes and freeze-frame data before clearing them or disconnecting the battery.
- TipAsk the shop to name the exact DTC and the failed factory test step before approving any throttle-body, pedal, wiring, or PCM part.
Sources for this issue (2)
P2138 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2138 mean on a Jeep?
P2138 stands for "Throttle/Pedal Position Sensor D/E Voltage Correlation." This code means the two (or three) signals from the accelerator pedal position / throttle position sensors disagree with each other — specifically sensors 'D' and 'E', which are typically the redundant signals built into the electronic accelerator pedal. Drive-by-wire systems use multiple sensors that should track together so the computer can trust the driver's input; when their voltages don't correlate, the computer can't be sure of the requested throttle and sets this code. As a safety response it usually puts the engine into a reduced-power 'limp' mode. It generally points to the pedal sensor assembly or its wiring. On Jeep it is documented across 1 model: Grand Cherokee.
What are the most common causes of P2138?
The most common causes of P2138 are: Faulty accelerator pedal position sensor assembly, Corroded or loose pedal sensor connector, Chafed, shorted, or open wiring between pedal and ECM, Shorted-together signal wires in the pedal harness, Poor sensor ground or reference voltage, Moisture or contamination in the pedal connector, Faulty ECM/PCM (less common). The specific cause varies by vehicle.
How much does it cost to fix P2138 on a Jeep?
Repair costs vary widely with the root cause and Jeep model; each issue on this page carries its own estimate where one is published.
Looking for P2138 on a different make?
View P2138 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.