Unconnecting the battery fixes the problem.....for a while.
01-20-2019, 10:31 PM
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2005 c55
Unconnecting the battery fixes the problem.....for a while.
Greetings!
I just bought a 2005 C55 with a problem. The problem is that the car gets locked into whatever gear it is in and then if you put it in park, it won't come out of park, unless you clear the problem (by restarting or battery disconnection). When the problem happens, the speedometer goes to zero, the check engine light comes on as well as the ABS light and, as mentioned, you're stuck in whatever gear you were in when the problem occurred.
So, say you start it up and things are fine (because you recently disconnected and then reconnected the battery) and you reach a highway and reach highway speed before the problem manifests itself; when the problem happens, you will be stuck in 5th gear until you clear the problem but either turning the car off and then back on OR by disconnecting the battery and then reconnecting it.
Sometimes you can solve the problem temporarily by turning off the car and restarting it. You can always temporarily clear the problem by unhooking the battery and then hooking it back up.
Clearing the problem by unhooking/rehooking the battery up seems to indicate to me that something is getting re-programmed (the transmission control module?) each time it loses power and then regains it.
I don't think it is the conductor plate because, I suspect, the problem wouldn't temporarily be fixed by unconnecting and then reconnecting the battery.
The problem manifests itself seemingly randomly but usually not long (20 minutes or less, usually) after start-up.
I think it is a faulty transmission control module, but I could be wrong and probably am.
What are your thoughts?
I intend to take it to a transmission shop nearby and then if that doesn't work, then to a specialist in Mercedes and BMW in Richardson, Texas called German Motor Works.
Oh, one last thing. I have another 2005 C55 but my daughter just wrecked it (that's why I bought the new one; they're awesome cars)......but.....I can take the TCM out of it (or any other part I want) and put it into the new one to see if that clears the problem.
Incidentally, the new C55 has the infotainment with the navigation system whereas the wrecked one does not. Does this mean they might also have different transmission control modules?
I just bought a 2005 C55 with a problem. The problem is that the car gets locked into whatever gear it is in and then if you put it in park, it won't come out of park, unless you clear the problem (by restarting or battery disconnection). When the problem happens, the speedometer goes to zero, the check engine light comes on as well as the ABS light and, as mentioned, you're stuck in whatever gear you were in when the problem occurred.
So, say you start it up and things are fine (because you recently disconnected and then reconnected the battery) and you reach a highway and reach highway speed before the problem manifests itself; when the problem happens, you will be stuck in 5th gear until you clear the problem but either turning the car off and then back on OR by disconnecting the battery and then reconnecting it.
Sometimes you can solve the problem temporarily by turning off the car and restarting it. You can always temporarily clear the problem by unhooking the battery and then hooking it back up.
Clearing the problem by unhooking/rehooking the battery up seems to indicate to me that something is getting re-programmed (the transmission control module?) each time it loses power and then regains it.
I don't think it is the conductor plate because, I suspect, the problem wouldn't temporarily be fixed by unconnecting and then reconnecting the battery.
The problem manifests itself seemingly randomly but usually not long (20 minutes or less, usually) after start-up.
I think it is a faulty transmission control module, but I could be wrong and probably am.
What are your thoughts?
I intend to take it to a transmission shop nearby and then if that doesn't work, then to a specialist in Mercedes and BMW in Richardson, Texas called German Motor Works.
Oh, one last thing. I have another 2005 C55 but my daughter just wrecked it (that's why I bought the new one; they're awesome cars)......but.....I can take the TCM out of it (or any other part I want) and put it into the new one to see if that clears the problem.
Incidentally, the new C55 has the infotainment with the navigation system whereas the wrecked one does not. Does this mean they might also have different transmission control modules?
Last edited by adriancrane7; 01-20-2019 at 10:37 PM.
01-21-2019, 01:28 AM
#2
Senior Member
Your transmission is going into limp mode. You need a scan tool capable of reading the transmission module codes to figure out why. When you disconnect the battery you are clearing those codes.
With any vehicle produced after 1996 this is always the first step.
If I had to guess the problem is electronic since the transmission operates fine (from your description) and only after a while does it register a fault. Get the codes read after the problem occurs (since you are clearing them when disconnecting the battery leaving nothing for the scan tool to find).
With any vehicle produced after 1996 this is always the first step.
If I had to guess the problem is electronic since the transmission operates fine (from your description) and only after a while does it register a fault. Get the codes read after the problem occurs (since you are clearing them when disconnecting the battery leaving nothing for the scan tool to find).
