Throttle/Pedal Position Sensor A Circuit Low Input
Diagnose P0122 throttle position sensor code. Learn why the TPS reads low and how to test and replace it.
Sensors & Electronics
Symptoms
- 1Check engine light on
- 2Hesitation or stumbling on acceleration
- 3Surging or erratic idle
- 4Reduced power or limp mode
- 5Harsh or delayed shifting
Common Causes
- 1Faulty throttle position sensor
- 2Damaged or shorted wiring
- 3Poor connector contact or corrosion
- 4Worn throttle body
- 5Bad ground or reference voltage
How to Fix
- 1Inspect TPS wiring and connector
- 2Check reference voltage and ground
- 3Test the TPS signal through its range
- 4Clean or replace the throttle body if worn
- 5Replace the TPS or throttle body if faulty
What Does P0122 Mean?
The P0122 code indicates that the Throttle Position Sensor (TPS) circuit is sending a voltage signal that is lower than the expected range. The TPS tells the ECM how far the throttle is open.Why TPS Data Matters
The ECM uses throttle position to control fuel delivery, ignition timing, and shifting. A low or erratic signal can cause hesitation, surging, and shifting problems.Common Causes
A faulty TPS, worn throttle body, or wiring problems are typical. On electronic throttle systems, this may involve the accelerator pedal sensor as well.How AI4Car Helps
AI4Car can display live throttle position as a percentage, helping you confirm whether the signal tracks smoothly as the throttle opens and closes.Related Codes
P0120P0121P0123P0124
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