AUTOMATIC TRUNK LID PROBLEMS ??????? - Benzworld.org

GODZILLA · 11-06-2005, 07:20 PM

Hey guys I thought I've seen everything that can go wrong with a w140 but the dealer can't even figure out this problem..........

The problem: At any time when you depress the brake pedal and shift into reverse from park...the trunk lid automatically unlocks and opens? And even after driving the car when you shift from drive to park... when the shifter passes the reverse selector the trunk pops open again! What could it be????? For now when I reverse out of a parking spot... the trunk pops open... I reverse out... then put it into neutral... and depress the emergecy brake, get out and close the trunk..... then get back in the car and drive off. WHAT A PAIN IN THE ASS !!!! The dealer spent 5 hours and could not even figure it out. They did not charge me so that was good. Oh my car is a 1997 S-500 w140 Coupe. The dealer told me that these w140 coupes were very hard to work on compared to the sedan. In any case I cant seem to figure it out and neither can the dealer, so your advise is needed and appreciated.......

I forgot to mention that every thing works on the car even the trunk accuator the vacuum pumps the trunk lid handle even retracts and hides away like it is suppose to. HELP GUYS !!!!

Thanks....Godzzzz

mbenzoi · 11-07-2005, 05:34 AM

wow! thats a really weird one. but im thinking of a short circuit somewhere on the pse pump and the selector lever. but how? this are two different systems. the best think to do i think is to have a wiring diagram and try to search that the two has in common. maybe the CAN, remote trunk release switch or software error of the pse. have you tried pushing hard the trunk? maybe its just the trunk locking mechanism is not making a good contact and somehow lost its grip due to bump everytime the gear is engage. please update us here. [:)]

carjoy · 11-07-2005, 08:09 AM

Godz, first, I only know enough to be dangerous, but I use my WIS db to try to learn what questions to ask. Apparently there is a "reverse assist" to the PSE on both pressure and vac. The WIS (so far as I can use it -- user-hostile interface) states a test procedure for the PSE contol module involving engaging reverse gear. Query whether the contol mod has bit the dust.

ychachad · 11-07-2005, 09:18 AM

I think someone messed around with the vaccuum pump, and crossed the lines from the back-up assist antennae to the trunk. If you just got the car, that may be a valid theory. If it just started, during the course of the ownership, then I may be inclined to believe in corrosion or even wiring harness cross jumping??? These are just wild guesses, as even the dealership has no idea. anyone else?

GODZILLA · 11-07-2005, 10:03 AM

Thanks guys for your reply, I called the dealer and they told me that they checked and tested the Vacuum Pump theory of crossed lines and that wasn't the problem. I asked the dealer if they can do a software test on the Ecu for problems, and they told me that that was the first thing they checked.

I wonder if there is an emergency manual trunk release cable located in the trunk area that might be tangled onto something, but then again what would it tangle with to only open the trunk on Reverse Gear? I know my Volvo has this emergency cable located behind the panels just in case you get locked in the trunk ! SAPRANOES STYLE! Any more theories on what it could be?

Thanks

coach3062 · 11-08-2005, 03:58 AM

I'm not an expert, but have you disconnected the reversing light sensor at the transmission and see if that has any effect. It won't cost you anything to try, and it may isolate the problem.

RSVMillenian · 11-08-2005, 12:13 PM

I am not sure about your problem, however, I am sure that the same Gremlin is causing your and my problem. Everytime steering wheel is adjusted the passenger rear view mirror goes to the lower possible setting. It is rwaly a pain in the a$$ since my wife and I drive the car and are using the memory settings everyday.

GODZILLA · 11-10-2005, 05:14 PM

Thanks guys, I will call the dealer tommorrow and ask about the reverse light theory! I still wonder what it could be...........I'll keep you guys updated.....
GODZZZZZZ

leosoft · 10-12-2006, 09:31 AM

Hi all,

I got exactly the same problem!!!!!! Did you finally found a solution on this problem??? Please heeellllpppppppppppppppp

Thanks,

Leo

NZ Benz · 10-12-2006, 03:37 PM

Quote:

Originally Posted by leosoft

Hi all,

I got exactly the same problem!!!!!! Did you finally found a solution on this problem??? Please heeellllpppppppppppppppp

Thanks,

Leo

I was looking through my fuse box the other day, and it seems that the same fuses control alot of dual systems some very unrelated to each other. Considering that when the relay for the wipers goes you end up turning on teh wipers and get the blinkers going all at the same time, I'd put my money on there being a busted regulator somewhere in the car, I wish I knew more, sorry.