P1516

DTC P1516

CIRCUIT DESCRIPTION




The commanded throttle position is compared to the actual throttle position. Both values should be within a calibrated range of each other. The engine control module (ECM) continuously monitors the commanded and actual throttle positions. If the ECM detects that the difference in these values are greater than the calibrated range, DTC 1516 will set.

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- The ignition voltage is greater than 8 volts.
- The system is not in Battery Saver Mode.
- The engine is running.
- DTC P0068 is not set.

CONDITIONS FOR SETTING THE DTC
The difference between the predicted and the actual throttle position is more than a calibrated amount.

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.OR
- Under certain conditions the control module commands the engine OFF.
- The message center displays Reduced Engine Power.

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.

TEST DESCRIPTION

Steps 1 - 9:

Steps 10 - 19:

Steps 20 - 27:

The numbers below refer to the step numbers on the diagnostic table.
8. The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
11. When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.