DURAMAX-P2135 serious Duramax ›

Throttle/Pedal Position Sensor/Switch "A" / "B" Voltage Correlation

The DURAMAX-P2135 (Duramax) diesel fault code means: Throttle/Pedal Position Sensor/Switch "A" / "B" Voltage Correlation. This is a serious severity code.

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Keep driving?
Yes, with caution
DIY difficulty
intermediate
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What Are the Symptoms of DURAMAX-P2135?

  • Check Engine Light on
  • Reduced power mode
  • Poor or no response to the accelerator pedal

What Causes DURAMAX-P2135? (Most Likely First)

  • Failed accelerator pedal assembly High
  • Damaged wiring or a corroded connector at the pedal High
  • Shared reference voltage or ground problem Moderate

Can I Still Drive with DURAMAX-P2135?

Yes, with caution. DURAMAX-P2135 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What does P2135 mean on a Duramax?

P2135 means Throttle/Pedal Position Sensor/Switch "A" / "B" Voltage Correlation. Pedal position sensors "A" and "B" are reporting values that do not agree with each other.

Is P2135 a Duramax-specific code?

No. P2135 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose DURAMAX-P2135?

  1. Watch sensors "A" and "B" together on a scan tool while slowly pressing the pedal.

  2. Inspect the pedal connector and harness.

  3. Check the reference voltage and ground to the pedal.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines P2135 as a generic OBD-II code)

P2135 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Gas / Automotive (OBD-II) Generic OBD-II definition for P2135

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More Duramax codes → Diesel home All diesel codes Heavy-duty Guides

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