nogassershere
Veteran Member
- Joined
- Apr 5, 2008
- Location
- Alabama
- TDI
- '05 Golf TDI, '00 Jetta TDI(SOLD), '84 Rabbit 5sp NA(SOLD), 06 Jetta TDI(SOLD)
So in the interest of full disclosure, I'm going to start from the beginning.
My wife's MKV Jetta was having AC issues last summer, I replaced the RCV and it got better. It also needed new cooling fans but we let it ride until this summer.
The small fan was working (somewhat) for most of the summer, it finally quit about the same time the driver's door harness issue popped up. I ordered a fan controller from my friendly neighborhood online retailer (was supposed to fit the car.) I fixed the door harness and removed the battery/air box, etc. to install the FCM.
This was when I realized the module was not correct for the MKV and I needed a new big fan/controller combo. I put the car back together and let my son drive it back to the front yard. The next day, my wife told me there were multiple lights lit up on the dash. I met her to check it out, the CEL, Power Steering, ABS, and Brake lights are all on, the speedometer is inop. and the fuel gauge drops sharply under hard acceleration.
I've been trying to troubleshoot while waiting on the new set of fans to arrive, and this is what I have found:
I am able to communicate with all but the ABS module via a VAG401 from XTOOL. I am able to read and clear codes from all other modules, the common thread being:
01316 - Brake Module
18259 - Data Bus Powertrain: missing message from ABS control.
When the new fans came in, I set out to replace them and try to find out what I inadvertently disconnected that would cause all of these new lights.
Fan replacement was successful, no change.
Removed the battery/air box again looking for something disconnected, nothing found, all fuses good (both boxes).
I found the ECU is loose in its cradle, the harness connection to the ABS module is visually ok, I pulled the release and tried to disconnect/inspect but was unable to because it was too hot by this point. I did get it to move a little and then locked it back in.
There are multiple other codes in other modules, I can clear them but most return instantly.
I suspect this is a wiring issue, possibly a ground somewhere. Does the ECU need to be case grounded?
Is there any direction I should concentrate my efforts?
Even the Climatronic module is throwing the 01316 code.
Not believing the HVAC has any need to talk to the brakes, I did some research and it seems that there may be an issue with the "circuit 15" connection somewhere.
I have a Bentley's for my MKIV, but not the 5 to see a wiring diagram. I'm not able to buy another manual right now and don't have a lot of time to commit to hunting a wiring issue (last two semesters of Engineering degree + 40+hours a week at work + family/kids.)
I know this is a bit long winded but I'm just trying to supply plenty of information in hopes that somebody has experienced something that might help.
Any and all help is appreciated.
My wife's MKV Jetta was having AC issues last summer, I replaced the RCV and it got better. It also needed new cooling fans but we let it ride until this summer.
The small fan was working (somewhat) for most of the summer, it finally quit about the same time the driver's door harness issue popped up. I ordered a fan controller from my friendly neighborhood online retailer (was supposed to fit the car.) I fixed the door harness and removed the battery/air box, etc. to install the FCM.
This was when I realized the module was not correct for the MKV and I needed a new big fan/controller combo. I put the car back together and let my son drive it back to the front yard. The next day, my wife told me there were multiple lights lit up on the dash. I met her to check it out, the CEL, Power Steering, ABS, and Brake lights are all on, the speedometer is inop. and the fuel gauge drops sharply under hard acceleration.
I've been trying to troubleshoot while waiting on the new set of fans to arrive, and this is what I have found:
I am able to communicate with all but the ABS module via a VAG401 from XTOOL. I am able to read and clear codes from all other modules, the common thread being:
01316 - Brake Module
18259 - Data Bus Powertrain: missing message from ABS control.
When the new fans came in, I set out to replace them and try to find out what I inadvertently disconnected that would cause all of these new lights.
Fan replacement was successful, no change.
Removed the battery/air box again looking for something disconnected, nothing found, all fuses good (both boxes).
I found the ECU is loose in its cradle, the harness connection to the ABS module is visually ok, I pulled the release and tried to disconnect/inspect but was unable to because it was too hot by this point. I did get it to move a little and then locked it back in.
There are multiple other codes in other modules, I can clear them but most return instantly.
I suspect this is a wiring issue, possibly a ground somewhere. Does the ECU need to be case grounded?
Is there any direction I should concentrate my efforts?
Even the Climatronic module is throwing the 01316 code.
Not believing the HVAC has any need to talk to the brakes, I did some research and it seems that there may be an issue with the "circuit 15" connection somewhere.
I have a Bentley's for my MKIV, but not the 5 to see a wiring diagram. I'm not able to buy another manual right now and don't have a lot of time to commit to hunting a wiring issue (last two semesters of Engineering degree + 40+hours a week at work + family/kids.)
I know this is a bit long winded but I'm just trying to supply plenty of information in hopes that somebody has experienced something that might help.
Any and all help is appreciated.
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