WinterPark321

During a 2hr road trip, the 2011 GL550 went into limp mode twice. Coincidentally, both times were past 75 mph. First time, limp mode came on, but no warning lights. Car was unable to accelerate, only high RPMs. Car was driven onto off ramp, and then eventually after stopping on the curb, the car shut itself off. Second time, the car did limp mode again. However, this time I pulled to the side and the car did not shut itself off, but was unable to accelerate.

I took the GL550 to the dealer the next day and after 4 days of diagnosis, they called me back saying there was no problem with the Vehicle and that I must've "accidentally pressed the paddle shifters" while driving. Has anyone else had problems like this? I scanned my car and code 1709 and a description of an ISM fault was read. However, when i told the dealer this, they said in the diagnosis computer, they did not find anything.....

Any comments?

kombifan

alx

your ism fault might or might not be current or the cause. ism errors also tend to be very doom-like (ie do not shift gears, drive to workshop messages on your console)...

also... nothing specific happens at 75mph. 7th gear is engaged around 60-65 when all fluids are at operating temp and throttle is applied lightly and in a smooth manner.

if the dealer did not read any codes and could not repro the issue, they would not do anything. however, by your description there should have been codes. limp mode generally is noisy and will leave audit-able log trails that can be accessed. when you connected your scanner are you sure you didnt clear the faults after you read them?

more info is needed.

WinterPark321

So Limp Mode happened again randomly today. Was driving the residential roads home today and was going about 20 mph when the car suddenly wouldn't accelerate. No check engine lights or any lights at all. Car would stay in "D". I slowed to a stop with the brake and put the car in park. I tried to shift back to D, N or R, but the dash still showed P. Shut the car off and suddenly everything is back to normal.

I did a diagnostic code search on the transmission part of the car and found new codes, as I cleared the previous code last time Limp mode occurred:
ETC - 1709 "The actuator motor in the component 'A80 (Intelligent Servo module(ISM) for direct select)' cannot reach its specified target position" - Stored
ETC - 0705 "Component "Y3/8s1 (Selection Range sensor)' is faulty" - Stored.

Does anyone have similar or any input?

Thanks