| Subject: | Park Assist System Inoperative, Service Park Assist Message on Driver Information Center (DIC), DTC B1E3A and/or B0954, B0955, B0956, B0957, B0958, B0959, B0960, B0961 (Replace Appropriate Object Sensor or Repair Harness) | 
| Models: | 2006-2008 Buick Lucerne | 
| 2008-2009 Buick Enclave | 
| 2006-2008 Cadillac DTS | 
| 2007-2009 Cadillac Escalade, SRX | 
| 2008-2009 Cadillac CTS | 
| 2007-2009 Chevrolet Avalanche, Silverado, Suburban, Tahoe | 
| 2009 Chevrolet Traverse | 
| 2007-2009 GMC Acadia, Sierra, Yukon, Yukon XL | 
| 2007-2009 Saturn OUTLOOK | 
| Equipped with Parking Assist (RPO UD7 or UFR) | 
Some customers may comment on a "Service Park Assist" message displayed on the DIC. Upon investigation, the technician may find DTC B1E3A and one or more of the following DTC's stored: B0954, B0955, B0956, B0957, B0958, B0959, B0960, B0961.
This may be caused by a malfunctioning object sensor or a circuit fault on the 8 volt reference circuit.
Notice: The 8 volt reference circuit serves all of the object sensors in parallel. A fault anywhere on the circuit or in any single sensor will affect all of the sensors.
When a single sensor malfunctions, the shared 8 volt reference circuit may be compromised, resulting in a DTC for each sensor.
Important: DO NOT replace all the sensors and/or the object alarm module.
If normal diagnosis does not reveal any concerns with the park assist system, perform the following diagnostic procedure:
Important: With all the park assist sensor harness connectors disconnected, multiple sensor DTCs will set and will not clear. Ignore these DTCs.
| • | If the DTC B1E3A is set, test the 8 volt reference circuit for a short to voltage/power or a short to ground. | 
| Important: Ensure each leg of the circuit is tested since the 8 volt reference circuit feeds all the sensors in parallel. | 
| • | Repair the faulty leg. | 
Part Number  | Description  | Quantity  | 
|---|---|---|
15239247  | Sensor Kit, RR Object  | 1  | 
For vehicles repaired under warranty, use:
Labor Operation  | Description  | Labor Time  | 
|---|---|---|
R4113  | Sensor, Front Object Alarm - Replace  | Use Published Labor Operation Time  | 
R4114  | Sensor, Rear Object - Replace  | Use Published Labor Operation Time  | 
N6620  | Wiring And/Or Connector- Power & Grounds - Repair Or Replace  | Use Published Labor Operation Time  |