Looking at a friend’s 2003 Jetta TDI automatic and what to check the connections to the TCM (transmission control module). Where did VW put it? I did search but could not find any links. Pictures would be great.
2003 Jetta TDI TCM module Placement
- Thread starter Red64
- Start date
oilhammer
Certified Volkswagen Nut & Vendor
In the cowl chamber next to the engine controller. Take the wiper arms off, then take the cabin filter cover off, then the cowl cover(s). It is the one on the passenger side.
Can we have some context into the nature of your problem? You may not actually have a TCM issue.
Can we have some context into the nature of your problem? You may not actually have a TCM issue.
Thanks for the info.
Most of the time the car will not move either forward or backward. There are no codes set and I checked the data blocks using VAGCOM and the TCM sees the gear selection and sets the solenoid bit pattern as it should, the pressure transducer voltage changes as motor RPM increases. I disconnected the trans plug and checked the solenoid coil resistance using a volt meter and every thing looked fine. Next step is to check the fluid level and pull the pan.
I did say most of the time, the puzzling part is that every now and again when you select either drive or reverse you feel the drive engage and the car will move in the selected direction.
I have two other VW's with similar transmissions and have worked on them both, so I understand most of the issues.
Thanks again for your input
Most of the time the car will not move either forward or backward. There are no codes set and I checked the data blocks using VAGCOM and the TCM sees the gear selection and sets the solenoid bit pattern as it should, the pressure transducer voltage changes as motor RPM increases. I disconnected the trans plug and checked the solenoid coil resistance using a volt meter and every thing looked fine. Next step is to check the fluid level and pull the pan.
I did say most of the time, the puzzling part is that every now and again when you select either drive or reverse you feel the drive engage and the car will move in the selected direction.
I have two other VW's with similar transmissions and have worked on them both, so I understand most of the issues.
Thanks again for your input
oilhammer
Certified Volkswagen Nut & Vendor
The TCM isn't your problem then. Even if the TCM was not even plugged in, the transmission will move forward and backward, because it would revert to just a simple hydromechanical unit. Limp mode is just a fixed gear, 3rd I think, and reverse will still work, it will just engage a bit harsh since the line pressure will not be regulated.
You have an internal trans problem.
Just FYI, the only VAG autobox sold here that I am aware of that is 100% totally dependent on the electronics to work correctly in order to move the car is the 02E (DSG). Because its 'limp mode' is neutral.
You have an internal trans problem.
Just FYI, the only VAG autobox sold here that I am aware of that is 100% totally dependent on the electronics to work correctly in order to move the car is the 02E (DSG). Because its 'limp mode' is neutral.
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teddibear
Member
I had a code pop up that said P0864 tcm communication circuit range/performance! This was after I had a interlock device installed not sure if that has anything to do with it. I also had a code pop up for glow plug cylinder 4 is open so I figure that means the glow plug is out. But haven't noticed any problems like with shifting or starting so I cleared the codes and drove the car more like 40 mins freeway driving and a hour around town the engine light came back on though the only code it shows is the glow plug. Could the tcm code have been a mistake? Or will it more then likely come back?