Circuit Description
The powertrain control module (PCM) supplies a 5-volt reference signal and a ground to the sensor. the throttle position (TP) sensor sends a voltage signal back to the PCM relative to throttle blade opening. Signal voltage will vary from 0.45 volts at closed throttle to over 4.5 volts at wide open throttle.
Conditions for Setting
| • | The TP sensor voltage is greater than 3.9 volts. |
| • | The engine speed is less than 1,500 RPM. |
| • | One or both of the following DTCs are not set; DTC P0107, DTC P0108. |
| OR |
| • | The TP sensor voltage is greater than 4.8 volts. |
| • | One or both of the following DTCs are not set; DTC P0107, DTC P0108. |
Action Taken
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The TP angle will default to 0 percent when the vehicle speed is less than 3 km/h (2 mph) and 10 percent when the vehicle speed is greater than 3 km/h (2 mph). The scan tool will display the defaulted value. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn OFF after passing three consecutive diagnostic tests. |
| • | A history DTC will clear after 40 consecutive ignition cycles have occurred without a fault. |
| • | History and current DTCs can be cleared by using a scan tool. |
Diagnostic Aids
| • | If a DTC P0123 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining how many ignition cycles have passed since last set. |
| • | With the ignition ON and the throttle at closed position, the voltage should read between 0.20 volts and 0.90 volts and increase steadily to over 4.5 volts at wide open throttle. |
| • | DTCs P0123 and P0113 stored at the same time could be the result of an open sensor ground circuit, CKT 452. |
| • | Inspect connectors for proper mating, replace or repair as necessary. |
Test Description
The number below refers to the step number on the diagnostic table.
-
The TP sensor has an auto zeroing feature. If the voltage reading is between 0.2-0.9 volts, the PCM will assume the TP sensor is at a closed throttle position.
-
Simulates a DTC P0123. If the PCM recognizes the high voltage signal, then the PCM and wiring are OK.
-
This simulates a high voltage signal which will identify an open in the signal circuit.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Was the On-Board Diagnostic (OBD) System Check perform? | -- | Go to Step 2 | |
Is the TP sensor voltage greater the specified value? | 1 V | Go to Step 4 | Go to Step 3 | |
3 |
Is the TP sensor voltage greater the specified value? | 1 V | Go to Step 4 | Go to Diagnostic Aids |
Is the TP sensor voltage less than the specified value? | 0.2 V | Go to Step 5 | Go to Step 6 | |
Probe the TP sensor ground circuit at the TP sensor harness connector with a test light connected to B+ Does the test light illuminate? | 4 V | Go to Step 7 | Go to Step 9 | |
6 |
Was a repair necessary? | -- | Go to Step 11 | |
7 |
Was a repair necessary? | -- | Go to Step 8 | |
8 | Inspect for poor electrical connections at the TP sensor and replace the terminals if necessary. Was a repair necessary? | -- | Go to Step 10 | |
9 |
Was a repair necessary? | -- | Go to Step 11 | |
10 | Replace the TP sensor. Is the action complete? | -- | -- | |
11 | Replace the PCM. Is the action complete? | -- | -- | |
