2007 Tahoe. This week my wife backed into another vehicle with absolutely min damage. The plastic bumper snapped right back into place with a gentle pop of my hand, but the "Service Park Assist" keeps coming on. There is a small rub on the bumper above one of the sensors. It sounds from looking at the postings on this thread that the communication from the sensor and the module may have been interrupted. Is this a fix I can handle myself(relatively good mechanical skills) or must it be done at the dealer? What is involved to get to the sensor?
Thanks for any assistance.
Pocomoke123 replies: I took my 2006 Montana SV6 minivan (which has four Ultrasonic Parking Assist Sensors in its rear bumper) to the dealer when the Parking Assist System (which is also sometimes called the Rear Obstacle Detection System) quit working recently. It has 40,000 miles and is usually parked on the street. I could think of 2 possible causes: (1) The second-from-left round sensor cover on the outside of the bumper sustained a SLIGHT impact (which only scratched the round sensor cover and pushed it 1/8 inch out of its proper position, but did NOT dent or push in the bumper), and (2) The system quit working when jack hammering began on the street where parked (The Owner's Manual in fact states on page 3-23 that the system may be affected by "VIBRATIONS FROM A JACKHAMMER," as well as by dirt, mud, etc.). We didn't know which of the 2 events was the cause, as they were VERY close in time.
My DIC (driver information center) displayed NO WARNING MESSAGE. The single flashing red light (instead of two flashing amber lights and one flashing red light) was the tip-off something was wrong with the system. I finally found the proper fuse, marked only as "Cruise Control, Climate Control, and RPA." (GM could have saved me some time had they simply written out "Rear Parking Assist" on the fuse diagram instead of just abbreviating it as "RPA.") The fuse (#17) was fine.
The service department says I have a BAD SENSOR, most likely from the IMPACT, which will cost $290 for the tiny part (OUCH!) and $210 for the labor (I'm guessing to open up the rear bumper). Adviser states the sensors are VERY FRAGILE, and it doesn't take much of an impact to damage one. There may be yet another charge to "paint" the new sensor, but this may or may not be necessary in MY case as my rear bumper is made of black plastic and is NOT matched to the BODY PAINT COLOR. So, $500.00 is my approximate repair cost at the dealer.
I'm kinda surprised that SO SLIGHT an impact actually killed one of my sensors. The bumper wasn't dented or pushed in. I hope they REALLY DID TEST THE SENSOR, for example, by swapping it with a good one (like you do if you want to be SURE that a light bulb really is NO GOOD before you throw it in the garbage can).
Also, I asked the adviser: When re-abling a disabled Park Assist System, does it require a re-flash of any computer software module on the car? (He told me "NO.") He seems to think the system will just start working again as soon as the "bad" sensor is replaced with a new sensor.
I couldn't really find much about the parking assist system on line, so I decided to sign up to post my experience.
It looked a bit more than I wanted to tackle which is unusual for me in the past. I ended up taking it to the dealer and after $279, the sensor was replaced and works fine. Sorry I don't have a better success story.