For 1990-2009 cars

### Circuit Description

The throttle position (TP) sensor is used by the powertrain control module (PCM) to determine the throttle plate angle for various engine management systems. The TP sensor is a potentiometer type sensor with 3 circuits:

• | A 5-volt reference circuit

• | A low reference circuit

• | A signal circuit

The PCM provides the TP sensor with a 5-volt reference circuit and a low reference circuit. Rotation of the TP sensor rotor from the closed throttle position to the wide open throttle (WOT) position provides the PCM with a signal voltage from less than 1 volt to more than 4 volts through the TP sensor signal circuit. When the conditions for running this DTC are met, the PCM will use the manifold absolute pressure (MAP) sensor in order to determine if the predicted operating range of the TP sensor is correct. A skewed MAP sensor may cause this diagnostic trouble code (DTC) to set, and should be tested for proper operation if the TP sensor is operating properly and if this DTC continues to set.

### Conditions for Running the DTC

• | DTCs P0107, P0108, P0122, P0123, P1106, P1107, P1121, or P1122 are not set.

• | The engine is running for more than 2 minutes.

• | The engine coolant temperature (ECT) is greater than 75°C (167°F).

• | The MAP reading is less than 50 kPa for a TP sensor skewed high test.

• | The MAP reading is greater than 70 kPa for a TP sensor skewed low test.

• | The MAP is steady for 5 seconds or more.

### Conditions for Setting the DTC

• | The TP sensor reading is greater than a predicted value when the MAP is below 50 kPa.

• | The TP sensor reading is less than a predicted value when the MAP is above 70 kPa.

• | The above conditions are present for 5 seconds.

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the MIL/DTC

• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.

• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.

• | Clear the MIL and the DTC with a scan tool.

### Diagnostic Aids

Inspect for the following conditions:

• | A skewed MAP signal--A skewed MAP signal may cause the PCM to incorrectly determine that the TP sensor is out of range. Inspect for an unusually low or high MAP reading. Refer to Manifold Absolute Pressure Sensor Diagnosis .

• | If the DTC is determined to be intermittent or if the TP sensor system is still suspect, refer to DTC P1121 .

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Engine Controls Schematics
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls
2 | Important: : If any other DTCs are set, diagnose those DTCs first.

1. Turn ON the ignition, with the engine OFF.
2. Observe the TP sensor angle parameter on the scan tool while slowly opening the throttle to wide open throttle (WOT).

• | Closed throttle value is the first value.

• | Wide open throttle (WOT) value is above the second value.

Does the TP Angle increase steadily and evenly from the Closed Throttle value to above the Wide Open Throttle value?

0%

98%

Go to Step 3

Go to Step 4

3 |

1. Observe the Freeze Frame/Failure Records data for this DTC.
2. Turn OFF the ignition for 30 seconds.
3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or as close to the Freeze Frame/Failure Records data that you observed.

Does the DTC fail this ignition?

--

Go to Step 4

Go to Diagnostic Aids

4 |

1. Turn OFF the ignition.
2. Disconnect the TP sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, observe the TP sensor voltage parameter.

Does the scan tool indicate TP sensor voltage at the specified value?

0 V

Go to Step 5

Go to Step 6

5 |

1. Turn OFF the ignition.
2. Connect a fused jumper wire between the 5-volt reference circuit and the signal circuit at the TP sensor harness connector.
3. Turn ON the ignition, with the engine OFF.
4. With a scan tool, observe the TP sensor voltage parameter.

Does the scan tool indicate TP sensor voltage at the specified value?

5 V

Go to Step 9

Go to Step 7

6 | With a DMM, test the TP sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12
7 | With a DMM, test the TP sensor 5-volt reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8
8 | Test the TP sensor signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 11
9 | Test the TP sensor low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10
10 | Inspect for a poor connection at the TP sensor harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12
11 | Inspect for a poor connection at the PCM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13
12 | Replace the TP sensor. Refer to Throttle Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 14 | --
13 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 14 | --
14 |

1. Use the scan tool in order to clear the DTCs.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

Go to Step 15

Go to Step 2

15 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List | System OK