Nate_Grauvogel
Veteran Member
This turned into a long post, so sorry... but any help would be great. (This is on a GLX, but the ABS is common to TDIs, and I know some smart people hang out here)
I'm getting pretty close to taking our car in to a dealer to deal with this, but don't really have that kind of money to throw at it. We just moved to Texas and inspection is comning due this month, where the system has to be working at least enough to turn off the "Brake" warning light. ("ABS" light alone will not fail the inspection.) Both are lit (Brake light only in the last month) and sometimes the brake light goes out, but not reliably enough to get it inspected - the manual says this means there is no elctronic proportioning active, and braking performance is compromised.
ABS is on the fritz - the codes have been saying there were three intermittent/broken wheel speed sensors for a year now, which I just replaced last night, and it did not fix it *sounds of money flushing away* (OK- one wheel code has not come back). Last night it never worked and the codes would not stay cleared. But, for about 5 minutes this morning during a test drive, all the codes stayed clear and the system worked (I made 2 or 3 ABS-assisted stops with no problems) - for about 5 minutes, then while nearing home, lo and behold, the three wheel speed sensor codes came back again.
I've checked all the pinouts on the connector at the pump/control unit per the manual, and no errors there. Last night when I logged in to clear the codes after replacing the sensors, there were some other codes that I had never seen before - V64 Hydraulic pump voltage and some voltage supply ones, too. They didn't come back during test drives - only the wheel speed sensor codes.
I haven't been able to locate a source of any electrical fault in the harness or the sensors (resistance and current check out OK)... is my control module bad? I hope not - that's a $608 part at wholesale price.
Related topic, too: rear wheel bearing play - how much is acceptable? There is no limit in the manual. I have no perceptible endplay, but both rear wheels have a little wobble that you can feel only with the tire mounted, more in the "camber" direction than the "toe" direction. I dare not tighten the bearings any more, for fear of binding... (or exceed the preload per the manual such that the thrust washer can't be moved without prying). Both rear sensors are throwing intermittent or no signal codes, but also one front one (whose wheel bearing is fine). I don't believe this is the source of the problem, but you never know...
Anyone have any suggestions? I'm about to throw in the towel and call my freundlichen (dealer)...
Thanks,
I'm getting pretty close to taking our car in to a dealer to deal with this, but don't really have that kind of money to throw at it. We just moved to Texas and inspection is comning due this month, where the system has to be working at least enough to turn off the "Brake" warning light. ("ABS" light alone will not fail the inspection.) Both are lit (Brake light only in the last month) and sometimes the brake light goes out, but not reliably enough to get it inspected - the manual says this means there is no elctronic proportioning active, and braking performance is compromised.
ABS is on the fritz - the codes have been saying there were three intermittent/broken wheel speed sensors for a year now, which I just replaced last night, and it did not fix it *sounds of money flushing away* (OK- one wheel code has not come back). Last night it never worked and the codes would not stay cleared. But, for about 5 minutes this morning during a test drive, all the codes stayed clear and the system worked (I made 2 or 3 ABS-assisted stops with no problems) - for about 5 minutes, then while nearing home, lo and behold, the three wheel speed sensor codes came back again.
I've checked all the pinouts on the connector at the pump/control unit per the manual, and no errors there. Last night when I logged in to clear the codes after replacing the sensors, there were some other codes that I had never seen before - V64 Hydraulic pump voltage and some voltage supply ones, too. They didn't come back during test drives - only the wheel speed sensor codes.
I haven't been able to locate a source of any electrical fault in the harness or the sensors (resistance and current check out OK)... is my control module bad? I hope not - that's a $608 part at wholesale price.
Related topic, too: rear wheel bearing play - how much is acceptable? There is no limit in the manual. I have no perceptible endplay, but both rear wheels have a little wobble that you can feel only with the tire mounted, more in the "camber" direction than the "toe" direction. I dare not tighten the bearings any more, for fear of binding... (or exceed the preload per the manual such that the thrust washer can't be moved without prying). Both rear sensors are throwing intermittent or no signal codes, but also one front one (whose wheel bearing is fine). I don't believe this is the source of the problem, but you never know...
Anyone have any suggestions? I'm about to throw in the towel and call my freundlichen (dealer)...
Thanks,