SeanR1700

Hey friends,

I drive an '05 S55 AMG. Today I was driving said car to lunch cruising at a comfortable 50 mph when all of the sudden I had a warning message pop up that said "PRE-SAFE NOT AVAILABLE, SEE OPERATORS MANUAL" or something to that effect. Once that popped up the car behaved as if it wouldn't shift below 3rd gear or was in limp mode or something, as the gear shifts felt sluggish and I had slow acceleration. Maybe it was in limp mode or something not sure.

I pulled off the road and shut the car off and started looking up how serious the message was on my phone, apparently it can indicate a variety of things. When I turned the car back on the message had disappeared and the car drove perfectly fine for the rest of the day. I tried it out in all transmission modes (Convenience / Sport / Manual) and did some spirited acceleration on some open highway entrance ramps and all was fine.

Was this just an unfortunate one time electrical glitch or a symptom of something more sinister?

Thanks for any help or insight anyone can provide, it is appreciated as always. This forum has always been a great help for me.

DrDoe

Hook up a code reader to see if it would register anything and go from there. If nothing then I wouldn't worry about it.
When was the last time the transmission got service? If you are worry then perhaps service the transmission as a preventive maintenance.

SeanR1700

The transmission had the fluid changed ect. done about 8k miles ago when the car was at ~99.5k miles

tusabes

Did you change the transmission electrical plug connector ? These are common sources of problems and they leak fluid into the tcu

SeanR1700

Yes my mechanic demanded I do so. The invoice reads "replaced transmission pan gasket, filter and electric plug adapter and fluid" so I would assume adapter here is the same as the connector as you mentioned.

amstel78

Just FYI, the plug adapter is technically called "transmission pilot bushing". But from your above description, it sounds like that was replaced.

rob_fed

Was the battery disconnected during the transmission work? If so, you may want turn your steering wheel lock-to-lock a few times (L - R - L - R - L - R). Then turn your car off, restart and it should clear, if the fault is related to the battery being disconnected.

SeanR1700

I'm not sure if the battery was disconnected but that service was 8k miles and close to 10 months ago so I can't imagine that would be the cause. There was no engine lights or anything just that one message "Pre-Safe Unavailable" which went away right after shutting the car off, no messages or engine lights currently. Been driving all week since and still haven't seen the message again or had any problems so I'm thinking (strongly hoping) it was probably a random electrical glitch.

tusabes

Yep probably random glitch

had you not driven the car for w Few days /weeks when you noticed the warning ?

it Might have been due to low initial voltage at startup until the alternator charged it back up

SeanR1700

I've driven the car nearly every day other than the occasional lazy Sunday for the last few months.

E42AMG???

I've had a asr warning pop up randomly and cruise control not work on another Mercedes but the asr warning went off after I shut it off and never came back after years. The cruise would work sometimes for a month then has worked fine ever since.

Check your battery cables and make sure they are on tight, or take them off and clean the terminals.