Abs U1255

LuborK · #1 (**permalink**) 03-20-05, 04:47 PM

Hello,
today I got "Speed limited to 145" (probably kph). Only current codes are ABS U1255 and PCM P1611 - except the "NO RSS DATA", which is related to the PCM P1611.
According to the factory service manual U1255 is Serial Data Line Malfunction and this DTC is set when some module does not respond via serial line in 5 seconds since request. Seems like ABS unit is completely dead. Does anyone experience with this? Today is too dark to work on it, but I would like to check the fuses and probably the connectors tomorrow.

I am not sure with the second error, which means Loss of CVRTD Serial Data and if ABS has to do with this too. Seems like CVRTD unit is dead too. ABS and CVRTD units are located on the different places (ABS unit should be under air filter, CVRTD under rear seat) which does not support my thought with one single reason causing two different errors.

I will try to follow steps described in FSM, but if anyone has a good advice, I would be very thankfull for it.

LuborK · #2 (**permalink**) 03-21-05, 10:34 AM

No advice for me?

Krashed989 · #3 (**permalink**) 03-22-05, 04:10 AM

U1255 - Class 2 Communication Malfunction (Serial Data Line Malfunction)
P1611 - Loss of CVRTD Serial Data

Since all of your codes referr to data loss, and there's nothing coming from RSS, I would start by checking fuses and relays, but I'm at a loss of information with this one... The RSS module is located behind the rear seat, you can get at it behind the carpeted fiberglass panel in the trunk. Sorry I can't give much help...

LuborK · #4 (**permalink**) 03-22-05, 04:40 AM

Thanks. Yesteray I was going to check rearbox fuses. I checked fuses 32 (CVRTD), 35 (ABS+TCS) and 12 (ABS switch) and all were OK. So I tried to start the car and check codes and everything was OK.
If U1255 and P1611 weren't as history, I would bet that I had only a bad dream :-). Hope it was just momental fault and does not occur in the future.

Krashed989 · #5 (**permalink**) 03-23-05, 03:58 AM

The thing is, RSS and ABS codes will not show up as current unless the car has just been driven and you check the codes before you turn it off. The next time you turn it on they will be history, and will then change back to current if the car has been driven and the problem still persists, however if the problem doesnt persist then it will stay as history until you clear it or it will be automatically cleared after a certain number of start ups.

LuborK · #6 (**permalink**) 03-23-05, 07:36 AM

But when I originally came to the car, I started the engine and I got "Speed limited" message almost imediatelly. And after I finished my ride, I checked the codes, turned car off, turned it on again (in the lot, without moving) and problem was still there. I will see today.

Krashed989 · #7 (**permalink**) 03-25-05, 04:29 AM

The car doesn't turn off all of the systems untill about a half an hour after you turn the engine off, and since the codes its showing would make the car not know that it even has a suspention system and/or properly working breaks, its limiting how fast you can go as a safety issue... I believe you would find more pertaining to this if you searched the forums for threads containing "speed limited to 90mph" I'm sorry I can't help you other than that.

zonie77 · #8 (**permalink**) 03-25-05, 11:51 AM

Check the grounds for those circuits. Bad grounds work in mysterious ways.

LuborK · #9 (**permalink**) 03-28-05, 02:12 PM

Thanks guys for your advices. Fortunatelly (or should I say "unfortunatelly"?) both codes where off just when I pulled the fuses, checked them and plugged them back. Now I drove 200 miles without single problem. I hope I will not see that codes again.