DTC P0121: Throttle Position (TP) Sensor Circuit Performance Problem: Condition
WARNING: This page is about a different car, the 2002 Suzuki Vitara. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when Engine Control Module (ECM) detects throttle opening is to small (rationality-low) while engine is operating under high load and high engine speed. DTC is also set when ECM detects throttle opening is to large (rationality-high) while engine is operating under low load and low engine speed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are:
- ECM malfunction.
- Throttle Position (TP) sensor malfunction.
- TP sensor circuit malfunction.