The throttle control module contains a throttle control motor, two throttle position (TP) sensors, and two independent signal circuits that vary resistance according to changes in throttle plate position. The ECM will go through a throttle position learn in procedure to determine acceptable values for the throttle plate position operating range. This is based on the inputs from TP sensor 1 and TP sensor 2 and feedback from the throttle control motor. DTC P1516 sets when the actual commanded throttle plate position differs from the commanded position a calibrated amount for a certain length of time.
DTC PARAMETERS
DTC P1516 sets when the actual commanded throttle plate position differs from the commanded position a calibrated amount when:
Condition exists for greater than 0.5 seconds
DTC P1516 diagnostic runs continuously with engine running.
P1516 is a (type A) DTC
DIAGNOSTIC AIDS
This DTC P1516 may set due to either mechanical faults or electrical circuit faults.
Possible causes:
| • | Throttle plate movement limited by carbon deposits |
| • | Circuit failure to throttle control motor |
| • | TP sensor not functioning properly (diagnose TP sensor DTCs first) |
| • | Throttle body assembly |
If both P1510 and P1516 are set, circuit 581 or 582 may be shorted to ground.
If both P1271 and P1516 are set, circuit 581 or 582 may be shorted to voltage.
P1516 may set due to circuit 581 or 582 open.
Important: If DTC P1516 is set, the ECM will default to REDUCED PERFORMANCE mode for the entire ignition cycle, even if the fault is corrected.
In REDUCED PERFORMANCE mode, throttle is limited to a maximum of 9.8% and the engine will respond slowly to throttle input.
