P1517

DTC P1517 Throttle Actuator Control (TAC) Module Performance

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. When the TAC module is unable to write or read data to and from RAM or the TAC module is unable to correctly read data from the flash memory or an internal TAC module processor fault is detected, this DTC will set which.

Conditions For Running the DTC

* DTC P1518 is not set.
* The ignition is in the crank or run position.
* The ignition voltage is more than 5.23 volts.

Conditions for Setting the DTC

* The TAC module determines that an internal data test did not pass.
* All above conditions met for less than 1 second.

Action Taken When the DTC Sets

* The PCM will illuminate the malfunction indicator lamp (MIL) and the Reduced Engine Power light will be on when this diagnostic fails.
* The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.
* If no other TAC System DTCs are set, the TAC System will operate in Reduced Engine Power Mode, and this DTC will be stored. If certain TAC System DTCs are set at the same time, the TAC System will either default to a more tightly restricted mode of operation if it is determined that limited safe operation is possible, or command engine shut down.

Conditions for Clearing the MIL/DTC

* The PCM will turn the MIL OFF after 3 consecutive drive trips that the diagnostic runs and does not fail.
* 40 consecutive warm-up cycles has occurred
A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
* A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
* PCM battery voltage is interrupted.

Important: The clear DTC info function may have to be performed twice in order to clear a throttle actuator Control System DTC.


* Using a scan tool

Diagnostic Aids

* Inspect for the following conditions that may cause an intermittent:

- Poor connections
- Inadequate terminal tension
- Corrosion
- Misrouted or damaged harness
- Rubbed through wire insulation
- Broken wire inside the insulation
- Water intrusion

* Inspect for further causes of intermittents. Refer Symptoms Symptoms.
* If a repair is completed and the DTC was cleared using a scan tool on the same ignition cycle, the default action will not clear until an ignition cycle has occurred.

Test Description

The number below refers to the step number on the diagnostic table.
4. When a problem is detected within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. It is possible that locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.