P1121

Circuit Description
The Throttle Position (TP) sensor is a potentiometer. The TP sensor is mounted to the left side of the throttle body. The TP sensor provides a voltage signal that changes relative to throttle blade angle. This signal voltage is one of the most important inputs used by the PCM. The TP sensor has a 5.0 volt reference, a ground and a signal circuit.
The TP sensor Signal voltage should be below 1.0 volt at idle. The TP sensor voltage should increase to above 4.0 volts at wide open throttle (WOT).
This DTC sets when the PCM senses a signal voltage higher than the normal operating range of the sensor.

Conditions for Running the DTC
The ignition switch is in the Run position.

Conditions for Setting the DTC
^ The TP sensor voltage is greater than 4.75 volts.
^ The intermittent condition exists for a total of 1.0 second during a 20.0 second time period.

Action Taken When the DTC Sets
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the MIL/DTC
^ A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL/DTC.

Diagnostic Aids

Important: Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

An intermittent DTC can be caused by electromagnetic interference (EMI). Inspect related circuits for being too close to secondary ignition wires and the generator.
For an intermittent, refer to Symptoms. Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. If DTC P0123 failed this ignition, indicates a hard failure is present. When a hard failure is present, both the hard and intermittent DTC sets.
3. When moving related connectors, visually/physically inspect connectors for the following:
^ Poor mating of the connector halves or a terminal not fully seated in the connector body (backed out).
^ Improperly formed or damaged terminals. All connector terminals in the related circuits should be carefully reform or replace to insure proper contact tension.
^ Poor terminal to wire connection. Inspect for poor crimps, crimping over wire insulation rather than the wire.
^ Dirt or corrosion on terminals. Inspect connector seals for being there and for being damaged.
4. When moving related wiring harnesses, visually/physically inspect wiring for the following:
^ Wire insulation that is rubbed through, causing an intermittent short.
^ Wiring broken inside the insulation.
5. Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This isolates when the DTC failed. If this DTC runs and passes the diagnostic, the scan tool may not indicate any information under DTC Status.