P1121moderate severityPowertrain

TP Sensor Circuit Intermittent High Voltage

on 2014 GMC Terrain 2.4L I4 · FWD

What this code means

The PCM detected intermittent high voltage spikes from the Throttle Position Sensor circuit.

Symptoms

  • Check Engine Light (intermittent)
  • Momentary surge or hesitation
  • Erratic idle
  • Intermittent Reduced Engine Power

Common causes

  • Loose TP sensor connector
  • Intermittent wiring fault
  • Worn TP sensor
  • Carbon buildup on throttle blade

Diagnostic steps

  1. Wiggle test TP sensor connector while monitoring
  2. Inspect wiring for chafing
  3. Test TP sensor through full range
  4. Check for carbon buildup in throttle body

Repair notes

Clean throttle body. Repair connector or replace TP sensor/throttle body.

Other Powertrain codes on this vehicle

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