Diagnostic Trouble Code
P0121 — Throttle Position Sensor A — Range/Performance Problem
Throttle Position Sensor A — Range/Performance Problem
Definition
The ECM has detected that the throttle position sensor A output does not correlate with expected values based on other engine parameters like MAP sensor, MAF sensor, and engine RPM. The signal may be erratic or inconsistent.
Common Causes
- Worn throttle position sensor with dead spots
- Sticking or binding throttle body
- Loose or corroded TPS connector pins
- Vacuum leak affecting MAP sensor correlation