P1516
DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
Circuit Description
Commanded throttle position (based on accelerator pedal position and possibly other limiting factors) is compared to the actual throttle position. The two values should be within a calibrated range of each other. Commanded and Actual throttle position are monitored redundantly within both the powertrain control module (PCM) and the TAC module. This DTC will set if the problem is detected by the TAC module.
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.
* Not in battery saver mode.
Conditions for Setting the DTC
* The TAC module detects that the commanded and actual throttle positions are not within a calibrated range of each other. The PCM and the TAC cannot determine throttle position, or both TP sensors are invalid.
* 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 have 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 cause of an intermittent. An intermittent may be caused by the following conditions:
- Poor connections
- Corrosion
- Misrouted harness
- Rubbed through wire insulation
- Broken wire inside the insulation
- Water intrusion
* Inspect for adequate terminal tension. Refer to Wiring Repairs Wiring Repairs in Wiring Systems.
* Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component problems can be located.
* 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 numbers below refer to the step numbers on the diagnostic table.
3. If the TP Indicated Angle does not follow the movement of the throttle blade, and no TP sensor DTCs are set, there is a mechanical problem with the throttle shaft or the TP sensor. Replace the throttle body assembly. Re-install the air inlet duct after you complete the repairs.
18. 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.
