Back to 1999 BMW 540iT E39

1999 BMW 540IT E39

4.4L V8RWDAUTOMATICgas
Repairs0Labor595Torque2626Fluid7DTC649Battery0Maintenance0Recalls0
P0120high severityPowertrain

Throttle/Pedal Position Sensor/Switch A Circuit

on 1999 BMW 540iT E39 4.4L V8 · RWD

What this code means

General malfunction in the throttle position sensor (TPS) or accelerator pedal position sensor circuit.

Symptoms

  • Check Engine Light
  • Erratic idle
  • Poor throttle response
  • Limp mode
  • Stalling

Common causes

  • Faulty TPS
  • Wiring damage
  • Throttle body issue
  • PCM failure

Diagnostic steps

  1. Test TPS voltage sweep (smooth transition 0.5-4.5V)
  2. Inspect wiring
  3. Check throttle body
  4. Test reference voltage

Repair notes

Replace TPS or throttle body assembly. Some vehicles require TPS relearn procedure.

Other Powertrain codes on this vehicle

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