P0120Infiniti Q50Years: 1996 - 2026
Throttle/Pedal Position Sensor/Switch A Circuit Malfunction
Reviewed by ASE Certified Technician
What does this mean?
Code P0120 indicates a malfunction in the Throttle Position Sensor (TPS) 'A' circuit. The PCM monitors the TPS to determine throttle blade angle.
Disclaimer: This diagnostic code is part of the standard OBD2 system and can apply to Infiniti Q50 models manufactured from 1996 to 2026. However, please note that the presence of this specific code depends on your vehicle's exact engine configuration, options, and production year.
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Common Causes
Faulty throttle position sensor (TPS)
Damaged, chafed, or broken wiring harness
Corroded or loose electrical connector
Dirty or faulty throttle body
Symptoms to Watch For
- Check Engine Light is illuminated
- Poor acceleration or sluggish response
- Engine surging or fluctuating RPM
- Engine stalling or dying unexpectedly
- Erratic or fluctuating idle speed
- Vehicle enters reduced power / limp mode