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P2128ModerateEngine

P2128 on 2007-2013 Chevrolet Avalanche — Throttle/Pedal Position Sensor E Circuit High Input

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

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Most Reported On

2007-2013Chevrolet Avalanche

P2128 is an OBD-II diagnostic trouble code meaning “Throttle/Pedal Position Sensor E Circuit High Input.” This code means the throttle or accelerator pedal position sensor 'E' is sending a signal voltage higher than its normal expected range. Modern vehicles use electronic throttle control, where pedal and throttle sensors (often with redundant 'E/F' channels) tell the computer how far the driver is pressing and how far the throttle is open. A high-input reading indicates an electrical fault such as a short to voltage or a wiring problem in that sensor channel. The computer may limit throttle response or enter a reduced-power 'limp' mode for safety until the fault is resolved. 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 pedal/throttle position sensor (channel E)
2Wiring shorted to voltage or power
3Corroded or damaged sensor connector
4Open or high-resistance ground/reference circuit
5Chafed or pinched harness wiring
6Faulty accelerator pedal assembly or throttle body
7Faulty engine control module (PCM) — rare

Typical Repair Cost

$100 - $500

Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose P2128, 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

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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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Best Value$90–$120

BlueDriver Pro Bluetooth Scanner

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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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Advanced$180–$230

LAUNCH CRP123X OBD-II Scanner

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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
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Professional$350–$450

Autel MaxiCOM MK808S Diagnostic Tool

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Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.

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Vehicles Affected (1)

Chevrolet P2128 page →
AvalancheModerate

Reduced Engine Power Mode from Throttle Body and Pedal Sensor Faults

2007-2013$100-$500310 reports

Related Codes (8)

P2120Throttle/Pedal Position Sensor/Switch "D" CircuitP2121Throttle/Pedal Position Sensor/Switch "D" Circuit Range/PerformanceP2122Throttle/Pedal Position Sensor/Switch "D" Circuit Low InputP2123Throttle/Pedal Position Sensor/Switch "D" Circuit High Input002FManufacturer-Specific Diagnostic Code00522Engine Coolant Temperature Sensor (G62): Open Circuit / Short to Positive (B+)16500Engine Coolant Temp. Sensor (G62): Implausible Signal16502Engine Coolant Temperature Sensor (G62): Signal too High

FAQ

What does P2128 mean?

P2128 stands for "Throttle/Pedal Position Sensor E Circuit High Input." This code means the throttle or accelerator pedal position sensor 'E' is sending a signal voltage higher than its normal expected range. Modern vehicles use electronic throttle control, where pedal and throttle sensors (often with redundant 'E/F' channels) tell the computer how far the driver is pressing and how far the throttle is open. A high-input reading indicates an electrical fault such as a short to voltage or a wiring problem in that sensor channel. The computer may limit throttle response or enter a reduced-power 'limp' mode for safety until the fault is resolved.

What are the most common causes of P2128?

The most common causes of P2128 are: Faulty pedal/throttle position sensor (channel E), Wiring shorted to voltage or power, Corroded or damaged sensor connector, Open or high-resistance ground/reference circuit, Chafed or pinched harness wiring, Faulty accelerator pedal assembly or throttle body, Faulty engine control module (PCM) — rare. The specific cause varies by vehicle.

How much does it cost to fix P2128?

Repair costs for P2128 range from $100 to $500, depending on the vehicle and root cause.

Which vehicles are affected by P2128?

Au7o has documented P2128 across 1 vehicle models from 1 manufacturers: Chevrolet.

Sources (1)

  • owner-reportAvalanche Engine Power Reduced Issues
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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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