P1121

Circuit Description

The Throttle Position (TP) sensor circuit provides a voltage signal that changes relative to throttle blade angle. The signal voltage will vary from 1.0 volt at closed throttle to 4.0 volts at Wide Open Throttle (WOT).

The TP signal is one of the most important inputs used by the PCM for fuel control and most of the PCM controlled outputs. If the PCM detects a TP signal that is intermittently above the range of the TP sensor, DTC P1121 will be set.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

^ TP sensor indicates a throttle position voltage intermittently greater than 4.7 volts.
^ The condition is present for longer than 5 seconds.

Action Taken When the DTC Sets

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

Conditions for Clearing the MIL/DTC

^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ DTC can be cleared by using a scan tool.

Diagnostic Aids

Check for the following conditions:

Important: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Diagrams.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the sensor display may indicate the location of the fault.
^ Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.