Circuit Description
The throttle actuator motor is a TAC controlled DC motor located on the throttle body. The motor drives the throttle plate. In order to decrease idle speed, the TAC commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the TAC commands the throttle plate open allowing more air to bypass the throttle plate. If the Actual idle RPM does not match the Desired idle RPM within a calibrated time, this DTC sets.
Conditions for Running the DTC
| • | DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0125, P0171, P0172, P0174, P0175, P0200, P0300, P0440, P0442, P0443, P0500-P0503, P1120, P1220, P1221, P1441 are not set. |
| • | The engine is operating for at least 60 seconds. |
| • | The ECT is greater than 60°C (140°F). |
| • | The IAT is greater than -10°C (14°F). |
| • | The BARO is greater than 65 kPa (9.4 psi) |
| • | The system voltage is between 9 volts and 18 volts. |
| • | Vehicle speed is less than or equal to 1.6 km/h (1 mph). |
| • | APP Indicated Angle is 0 percent. |
Conditions for Setting the DTC
| • | The Actual idle speed is 100 RPM lower than the Desired idle speed. |
| • | All of the above conditions present for 5 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A last test failed, or current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the MIL and the DTC. |
Diagnostic Aids
Important:
• Remove any debris from the PCM\TAC module connector surfaces before
servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets
when diagnosing/replacing the modules. Ensure that the gaskets are
installed correctly. The gaskets prevent contaminate intrusion into
the PCM\TAC modules. • For any test that requires probing the PCM or a component
harness connector, use the Connector Test Adapter Kit J 35616
. Using this kit prevents damage
to the harness/component terminals. Refer to
Using Connector Test Adapters
in Wiring Systems.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
Does the engine speed correspond, within 100 RPM, with each command? | -- | Go to Diagnostic Aids | ||||||
3 | Is the engine RPM greater than 100 RPM above Desired RPM? | -- | ||||||
4 |
Is the action complete? | -- | -- | |||||
5 |
Is the action complete? | -- | -- | |||||
6 |
Does the scan tool indicate that this test ran and passed? | -- | ||||||
7 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
