- Joined
- Feb 8, 2007
- Messages
- 20,430
- Location
- Portsmouth, Hampshire.
- Car
- E55K SL500 E250X2 Smart44 Brabus Track car E450Cabriolet X350 Pick up
Hello all,
I have had Howards car in for its gearbox fault and I thought I would share the problem and remedy with you all just incase you come across this issue. This fault has tested me!
The car is a CLK 320 208 chassis. The problem occured when the car was driven off the lights at a reasonable speed
.
The gearbox was going into limp mode intermittantly. I put the car on my Star and it came up with a coding fault with the selector module which I was VERY sure was the cause of the problem. Under inspection a drink had been spilt over it at some point leaving a sticky mess. I was adament that this was the problem as the actual values on the Star were giving me incorrect selector positions.
I replaced the selector and regained the correct vaules on the Star but the problem was still there
.
Ok, so I decided to delve a bit deeper so cleaned up all the connections to and from the selector to the K40 relay unit. (where the selector gets its power from). I was still sure that somehow the selector or somthing with the selector was causing the issue.
I went on a few more road tests and another fault code poped up (that I had not seen as yet) with the speed sensor within the gearbox. Speed sensors are a very common issue so I fitted a new electrical plate (speed sensor is whithin the electrical plate)
I then went on another road test and all seemed fine until I turned round to head back to the workshop. Back in limp mode
I was now getting frustrated becuase the Star was not giving me anything to go on and without fault codes it is very difficult to pinpoint engine and gearbox issues. I always use fault codes as a guide and not the answer to problems but without them its makes a difficult job much harder.
Note: The gearbox is fairly newish (Howard can confirm how old)
The items left that could be causing this issue were the gearbox itself or the control unit. I swapped the control unit from my 202 and it made no difference. Maybe the gearbox was faulty? I was not sure.
During all this diagnosing I had a couple of MB Techs come round the workshop and have a look with me. Both of them are Diagnostic Technicians and well respected as knowing their mustard. They had no clue.
I was still not convinced that the gearbox itself could be causing this issue.
I took the Star out on road test with me to check some values while driving. I spotted somthing.....
A fault code flashed up very quickly and went away. It said something about implausability.
I found the problem.
Can you guess what it was?
(Dieselman and Howard cannot answer 'cos I have already told them)
I have spent a grand total of 30 hours on this problem!
I have had Howards car in for its gearbox fault and I thought I would share the problem and remedy with you all just incase you come across this issue. This fault has tested me!
The car is a CLK 320 208 chassis. The problem occured when the car was driven off the lights at a reasonable speed
.The gearbox was going into limp mode intermittantly. I put the car on my Star and it came up with a coding fault with the selector module which I was VERY sure was the cause of the problem. Under inspection a drink had been spilt over it at some point leaving a sticky mess. I was adament that this was the problem as the actual values on the Star were giving me incorrect selector positions.
I replaced the selector and regained the correct vaules on the Star but the problem was still there
.Ok, so I decided to delve a bit deeper so cleaned up all the connections to and from the selector to the K40 relay unit. (where the selector gets its power from). I was still sure that somehow the selector or somthing with the selector was causing the issue.
I went on a few more road tests and another fault code poped up (that I had not seen as yet) with the speed sensor within the gearbox. Speed sensors are a very common issue so I fitted a new electrical plate (speed sensor is whithin the electrical plate)
I then went on another road test and all seemed fine until I turned round to head back to the workshop. Back in limp mode
I was now getting frustrated becuase the Star was not giving me anything to go on and without fault codes it is very difficult to pinpoint engine and gearbox issues. I always use fault codes as a guide and not the answer to problems but without them its makes a difficult job much harder.
Note: The gearbox is fairly newish (Howard can confirm how old)
The items left that could be causing this issue were the gearbox itself or the control unit. I swapped the control unit from my 202 and it made no difference. Maybe the gearbox was faulty? I was not sure.
During all this diagnosing I had a couple of MB Techs come round the workshop and have a look with me. Both of them are Diagnostic Technicians and well respected as knowing their mustard. They had no clue.
I was still not convinced that the gearbox itself could be causing this issue.
I took the Star out on road test with me to check some values while driving. I spotted somthing.....
A fault code flashed up very quickly and went away. It said something about implausability.
I found the problem.
Can you guess what it was?
(Dieselman and Howard cannot answer 'cos I have already told them)
I have spent a grand total of 30 hours on this problem!
