P2128 — Throttle/Pedal Position Sensor/Switch E Circuit High

P2128: Throttle/Pedal Position Sensor/Switch E Circuit High — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Throttle/Pedal Position Sensor/Switch E Circuit High. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

  • A check-engine warning may accompany an abnormally high channel-E signal.
  • Acceleration may be restricted or respond unpredictably.

Possible causes

  • Connector corrosion, wire damage or a short to supply in the E circuit.
  • A defective position sensor or unreliable sensor ground.

What to check

  • Read P2128 and associated throttle/pedal trouble codes.
  • Inspect the E-channel sensor connectors and wiring for poor contacts or moisture.
  • Compare live E-channel data with other position channels during gentle pedal movement.
  • Check signal, supply and ground against vehicle specifications before replacing a sensor or controller.

Also written as: P2128-00, P212800 (some scan tools add the fault-type byte, e.g. -00).