| Subject: | Engine Power Reduced or Starting Disabled Service Throttle |
| Models: | 2006- 2009 Buick Lucerne |
This PI was superseded to update model years and Recommendation/Instructions. Please discard PIC4559.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
A customer may comment about one or more of the following concerns. These concerns may be intermittent:
| • | Malfunction Indicator Lamp (MIL)/ Check Engine Light is illuminated
|
| • | ENGINE POWER REDUCED or STARTING DISABLED SERVICE THROTTLE messages displayed on the Driver Information Center (DIC)
|
| • | The engine will not start
|
One or more of the following DTC may be stored:
| • | P0452 Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage |
| • | P0650 Malfunction Indicator Lamp (MIL) Control Circuit |
| • | P2120 Accelerator Pedal Position (APP) Sensor 1 Circuit |
| • | P2122 Accelerator Pedal Position (APP) Sensor 1 Circuit Low Voltage |
| • | P2123 Accelerator Pedal Position (APP) Sensor 1 Circuit High Voltage |
| • | P2125 Accelerator Pedal Position (APP) Sensor 2 Circuit |
| • | P2127 Accelerator Pedal Position (APP) Sensor 2 Circuit Low Voltage |
| • | P2128 Accelerator Pedal Position (APP) Sensor 2 Circuit High Voltage |
| • | P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation |
The cause may be poor electrical connections in C111/ X111 Body Harness to the Engine Harness.
Recommendation/Instructions:
Inspect C111/ X111 for poor connections. Begin with inspecting the lever lock for damage and for it being completely locked. Open the connector and inspect for bent male pins and spread female pins. Gently tug on each wire going into and out of the connector
to ensure each terminal is locked into the connector, and that the terminals are not pushing out when the connector is closed and the lever is locked. Remove pins for suspect circuits from the connector and inspect for proper crimping of the pins. C111/ X111
is located on the LF Strut Tower in the Engine Compartment.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
