P1121

Schematic:

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.

TP sensor Signal voltage should be about 0.6 volt at idle. The TP sensor voltage should increase to above 4.0 volts at Wide Open Throttle (WOT). When the PCM senses a signal voltage higher than the normal operating range of the sensor, this DTC sets.

CONDITIONS FOR RUNNING THE DTC
The ignition switch is in the Run position.

CONDITIONS FOR SETTING THE DTC
^ The TP sensor voltage is more than 4.8 volts.
^ The intermittent condition exists for a total of 1 second during a 20 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 40 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 contaminate intrusion into the PCM.
^ For any test that requires probing the PCM or a component harness connector, use the J 35616-A connector test adapter kit. Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Diagrams.

Electromagnetic interference (EMI) can cause an intermittent DTC. Inspect the related circuits for being too close to secondary ignition wires and the generator.

If the engine has sat overnight, the engine coolant temperature and intake air temperature values should display within a few degrees of each other. If the temperatures are not within 3°C (5°F), refer to Temperature vs Resistance.

For an intermittent condition, refer to Symptoms. Symptom Related Diagnostic Procedures

TEST DESCRIPTION

Steps 1 - 4:

Steps 5 - 10:

Number(s) below refer to step numbers on the diagnostic table.
2. If DTC P0123 also failed this indicates a hard failure is present. When a hard failure is present, both the hard and intermittent DTCs will set.
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. Carefully reform or replace all connector terminals in the related circuits in order to insure proper terminal 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 for missing connector seals and for damage to the connector seals.
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 the DTC cannot be duplicated, the information included in the Freeze Frame and/or Failure Records data can be useful in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also be used to determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that were noted. This will isolate when the DTC failed. If this DTC runs and passes the diagnostic, the scan tool will not indicate any information under DTC Status.