Solving the mystery of the phantom beep
Owners of 2009-2010 Buick Lucerne equipped with Rear Park Assist RPO UD7 and 2009-2010 Cadillac DTS equipped with Front/Rear Park Assist RPO UFR may complain, while, in reverse gear, about an alert warning from a “false detection” (a quick beep with the rear yellow LED display kit momentarily) indicating the presence of an object in the ultrasonic park assist (UPA) sensors field of view, when in fact there may not be any object present. The phantom beeps are usually random and at times can be prolonged.
This condition may be caused by the object alarm module software being unable to filter a possible object detected by the UPA sensors from external environmental interference. The module incorrectly interprets UPA sensor data received as an object and incorrectly sends a warning alert for this false detection.
The repair involves reprogramming the object alarm module.
A revised calibration has been developed to address this condition. Technicians are to reprogram the object alarm module using service programming system (SPS) with the latest software available on TIS2WEB.
When using a Tech 2 or a Multiple Diagnostic Interface (MDI) for reprogramming, ensure that it is updated with the latest software version.
During programming, the battery voltage must be maintained within the proper range of 12-15 volts. Only use the approved Midtronics PSC 550 Battery Maintainer (SPS Programming Support Tool EL-49642) or equivalent during programming.