P2138: Throttle/Pedal Position Sensor D/E Voltage Correlation
3 vehicles · 3 makes · $150-$700 repair
Most Reported On
P2138 is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 2014-2022 Chevrolet Silverado 1500, 2010-2017 GMC Terrain (SLE, SLT, Denali), and 2011-2022 Jeep Grand Cherokee, with repair costs ranging from $150 to $700.
Common Causes
Typical Repair Cost
Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P2138, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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Vehicles Affected (3)
FAQ
What does P2138 mean?
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.
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?
Repair costs for P2138 range from $150 to $700, depending on the vehicle and root cause.
Which vehicles are affected by P2138?
Au7o has documented P2138 across 3 vehicle models from 3 manufacturers: Chevrolet, GMC, Jeep.
Sources (8)
- ForumService Stabilitrak, Service Traction Control, and Reduced Engine Power — anyone? — GM Truck Club Forum
- ForumService traction control, service stabilitrak — Chevy Silverado and GMC Sierra Forum
- articleHere's Why Your GMC Terrain May Have Reduced Engine Power
- ForumGMC Terrain: engine power reduced and check engine light is on
- articleGMC Terrain Throttle Body Guide: Symptoms, Replacement, and Costs (2010-2021)
- Forum'Service Stabilitrak' followed by 'Engine Power is reduced!' - GMC Terrain Forum
- Manual2011 Jeep Grand Cherokee Factory Diagnostic Procedure: P2111 ETC Unable to Close
- Manual2011 Jeep Grand Cherokee Factory Diagnostic Procedure: P2138 Pedal Sensor Correlation
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.