For 1990-2009 cars

### Circuit Description

The Throttle Actuator Control (TAC) Module contains data which is essential for proper ETC 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 communicated to the PCM across serial data and this DTC sets.

### Conditions for Running the DTC

• | The ignition switch is in the crank or run position.

• | DTC P1518 is not present.

### 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) during the first trip in which the diagnostic runs and fails.

• | If equipped with traction control, the PCM will command the EBTCM via the serial data circuit to turn OFF traction control and illuminate the TRACTION OFF lamp.

• | The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.

### Conditions for Clearing the MIL/DTC

• | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.

• | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• | The DTC can be cleared by using the scan tool.

### Diagnostic Aids

Important: Remove any debris from the connector surfaces before servicing component. Inspect the connector gaskets when diagnosing/replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

• | For an intermittent, refer to Symptoms .

• | If a repair is complete and the DTC was cleared by using a scan tool on the same ignition cycle, the default action will not clear until an ignition cycle has occurred.

• | When the TAC module detects a problem within the ETC System the PCM receives a message across serial data and more than one ETC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. When the TAC module detects a problem within the ETC System the PCM receives a message across serial data and more than one ETC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

#### DTC P1517 - Throttle Actuator Control (TAC) Module Processor

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Important: If any other DTCs are set, refer to the appropriate DTC first for further diagnosis. Replace the TAC Module. Refer to Accelerator Pedal Replacement . Did you complete the replacement? | -- | Go to Step 3 | --
3 |

1. With a scan tool, record Fail Records an clear DTCs.
2. Operate the vehicle within the Fail Record conditions.

Does the scan tool indicate this DTC failed this ignition?

--

Go to Step 2

Go to Step 4

4 | Does the scan tool indicate any DTCs set that you have not diagnosed? | -- | Go to the applicable DTC table | System OK