SFI SYSTEM, Diagnostic DTC:P0121
| DTC Code | DTC Name |
|---|---|
| P0121 | Throttle / Pedal Position Sensor / Switch "A" Circuit Range / Performance Problem |
DESCRIPTION
Refer to DTC P0120 Click here.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0121 | Difference between VTA1 and VTA2 voltages less than 0.8 V, or more than 1.6 V for 2 seconds (1 trip detection logic) | Throttle position sensor (built into throttle body) |
FAIL-SAFE
When this DTC, as well as other DTCs relating to electronic throttle control system malfunctions, is set, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator off, and the throttle valve is returned to a 6° throttle angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue at a minimal speed. If the accelerator pedal is depressed slowly, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is then turned off.
INSPECTION PROCEDURE
Tech Tips
Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.
