Circuit Description
During Battery Saver Mode the throttle actuator control (TAC) module determines if the throttle plate is returning to the correct de-energized position. If this fault is detected the TAC module sends a message to the powertrain control module (PCM) across serial data and this DTC is set.
Conditions for Running the DTC
| • | DTC P1518 is not set. |
| • | The ignition is ON and the engine is OFF. |
| • | The ignition voltage is more than 8.5 volts. |
| • | The Battery Saver Mode is active. |
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.
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
Conditions for Clearing the DTC
| • | 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 non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Diagnostic Aids
If you DO NOT find any trouble, inspect for mechanical conditions or binding that may be temperature related. Components may not move freely in extreme heat or cold due to the presence of contaminants or ice formation.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 | Are any other DTCs set? | -- | Go to Step 3 | |
3 |
Does the scan tool indicate throttle position within the specified values? | 10.8-23.2% | Go to Step 6 | Go to Step 4 |
4 | Remove the throttle body of the TAC assembly. Refer to Throttle Body Assembly Replacement . Did you find any obstructions preventing the throttle blade from returning to the default position? | -- | Go to Step 5 | Go to Step 6 |
5 | Remove the obstruction. Did you complete the repair? | -- | Go to Step 7 | -- |
6 | Replace the throttle body of the TAC assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement? | -- | Go to Step 7 | -- |
7 |
Does the DTC run, and pass? | -- | Go to Step 8 | Go to Step 2 |
With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | ||
