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P2138CriticalEngine

P2138 on 2007-2013 Chevrolet Avalanche — Throttle/Pedal Position Sensor D/E Voltage Correlation

1 vehicles · 1 makes · $100-$500 repair

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Most Reported On

2007-2013Chevrolet Avalanche

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 2007-2013 Chevrolet Avalanche, with repair costs ranging from $100 to $500.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (1)
  • Related Codes
  • FAQ
  • Sources (1)
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Common Causes

1Faulty accelerator pedal position sensor assembly
2Corroded or loose pedal sensor connector
3Chafed, shorted, or open wiring between pedal and ECM
4Shorted-together signal wires in the pedal harness
5Poor sensor ground or reference voltage
6Moisture or contamination in the pedal connector
7Faulty ECM/PCM (less common)

Typical Repair Cost

$100 - $500

Based on 1 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.

Budget Pick$10–$20

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+).

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  • I/M readiness status
  • No batteries or app needed
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Best Value$90–$120

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)
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  • Smog check readiness
  • Free app (iOS & Android)
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Advanced$180–$230

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
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Professional$350–$450

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)
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  • Oil reset, EPB, BMS, TPMS, injector coding
  • 7-inch touchscreen with Android OS
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Vehicles Affected (1)

Chevrolet P2138 page →
AvalancheModerate

Reduced Engine Power Mode from Throttle Body and Pedal Sensor Faults

2007-2013$100-$500310 reports

Related Codes (8)

P2135Throttle/Pedal Position Sensor Voltage Correlation002FManufacturer-Specific Diagnostic Code16566Mass Air Flow Sensor Signal Too Low (VAG)ECM-940AEngine Control Module Fault (Volvo)P0008Engine Position System Performance - Bank 1P0009Engine Position System Performance - Bank 2P0010Intake Camshaft Position Actuator Circuit (Bank 1)P0011Intake Camshaft Position Timing - Over-Advanced (Bank 1)

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 $100 to $500, depending on the vehicle and root cause.

Which vehicles are affected by P2138?

Au7o has documented P2138 across 1 vehicle models from 1 manufacturers: Chevrolet.

Sources (1)

  • owner-reportAvalanche Engine Power Reduced Issues

Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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