Circuit Description
The throttle actuator control (TAC) module contains data, which is essential for proper TAC system operation. The TAC module continuously checks the integrity of this data. If the TAC module is unable to write or read data to and from random access memory (RAM), or the TAC module is unable to correctly read data from the flash memory, or an internal TAC module processor fault is detected, DTC P2108 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P2108 Throttle Actuator Control (TAC) Module Performance
Conditions for Running the DTC
| • | The ignition is in the crank or run position. |
| • | The ignition voltage is more than 5.23 volts. |
| • | The communication between the TAC module and the powertrain control module (PCM) must be valid. |
Conditions for Setting the DTC
The TAC module determines that an internal data test did not pass.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records. |
| • | The control module commands the TAC system to operate in the Reduced Engine Power mode. |
| • | A message center or an indicator displays Reduced Engine Power. |
| • | Under certain conditions the control module commands the engine OFF. |
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. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 | Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | Go to Step 3 | -- |
3 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 4 |
4 |
Important: Be aware that repairing 1 individual condition may correct more than 1 DTC. Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |
