P2136

Throttle/Pedal Pos Sensor/Switch A / C Voltage Correlation

P2136 is a generic OBD-II powertrain diagnostic trouble code: Throttle/Pedal Pos Sensor/Switch A / C Voltage Correlation. It is logged by the engine control unit when the throttle monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P2136
Group
Powertrain
System
Throttle
Severity
Warning (MIL on, possible limp mode)
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What P2136 means

P2136 indicates that the PCM has detected a voltage correlation fault between throttle or pedal position sensor circuits designated A and C. In systems with more than two sensor tracks, the PCM checks multiple pairings independently. P2136 specifically flags the A-to-C relationship as falling outside the programmed correlation tolerance.

This code is part of the broader family of ETC redundancy faults designed to detect single-point sensor failures before they result in uncontrolled throttle events. When the A and C channels disagree beyond acceptable limits, the PCM cannot confidently determine true throttle or pedal position and will activate a protective mode.

Diagnosis begins with live data to compare the A and C channel voltages simultaneously during a controlled input sweep. A healthy system shows a predictable and consistent mathematical relationship between the two channels throughout the entire range. Circuit faults, sensor wear, and connector issues are the most common physical causes.

Common causes

Most-frequently reported root causes when P2136 is logged.

  • 1
    Throttle or pedal position sensor track A or C failed or drifted.
  • 2
    Wiring fault (open, short to ground, or short to voltage) on the A or C signal circuit.
  • 3
    Connector pin corrosion or damage affecting one of the two signal circuits.
  • 4
    Sensor reference voltage supply degraded, affecting one track more than the other.
  • 5
    Mechanical wear or contamination inside the sensor altering one track transfer function.
  • 6
    Aftermarket sensor installed with different transfer characteristics than OEM specification.
  • 7
    PCM calibration or software fault affecting the correlation check thresholds.

Symptoms drivers notice

MIL illuminated with reduced engine power or limp-home mode active.
Erratic or unresponsive throttle during acceleration.
Possible traction control or stability control warning lights.
Engine speed may be clamped at a reduced limit.
Fault may appear intermittently under vibration or temperature extremes.

How to diagnose P2136

A typical diagnostic flow when this code is present.

  1. 1
    Record all DTCs and freeze frame data before any repairs.
  2. 2
    View live data for TP-A and TP-C (or APP-A and APP-C) simultaneously and sweep through the full range.
  3. 3
    Verify the expected correlation relationship is maintained throughout the sweep.
  4. 4
    Inspect wiring and connectors for the A and C circuits, paying attention to shared ground paths.
  5. 5
    Check reference voltage supply to the sensor.
  6. 6
    Substitute the suspect sensor assembly with a known-good part and retest.
  7. 7
    Perform any required relearn or calibration procedure after sensor replacement.

Related powertrain codes

Frequently asked questions

How is P2136 different from P2135?

P2135 flags a correlation fault between sensor circuits A and B, while P2136 flags A and C. Each code identifies a specific sensor pair that has fallen outside its correlation tolerance.

Can a bad ground cause P2136?

Yes. A high-resistance or intermittent sensor ground can shift one channel voltage reading relative to the other, creating an apparent correlation fault even if the sensor itself is serviceable.

Is a relearn required after fixing P2136?

Yes. After replacing a throttle body or accelerator pedal assembly, the relevant relearn or idle learn procedure must be performed to re-establish the PCM baseline position data.

Can this code be caused by a loose sensor connector?

Yes. A partially unseated or corroded connector can cause intermittent open circuits on one channel, producing a correlation fault that comes and goes with temperature or vibration.

Disabling P2136 in software

RaceTune can permanently disable P2136 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

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