Vauxhall Astra 1.7D 1997 - ABS fault, MIL on permanently #Archived Message
Posted by Steve Gittins. on April 28, 2009, 1:00 pm
I have an ABS problem with an old (ex police force) 1997 Astra fitted with a Bosch ABS system part number 0 265 208 011 768/207631. The ABS light stays on permanently when the car is started. I first tried to communicate with the unit using autodiagnos but had no success. I wasn't sure if Communication was possible with this system so found some Pin out info from Autodata and checked Wheel sensor values which are all good even when flexing the wiring. I then scoped an output from each, they all show a good waveform. I then checked for supplies and earths (with the unit plugged in and ign on) all pins have either bat' voltage or a good earth as per the pin out diagram. Looking through the Autodata information the earlier systems with the GM 10 pin plug will give flash codes but this astra has a 16 pin OBD type plug. I then traced the wiring diagram back to the ABS unit plug to see if I could retrieve blink codes but the pin shown for Blink codes on the GM 10 pin plug system is empty on the car we have (With 16 pin socket) but there is an unknown pin on the car (pin 14) which is not shown on the autodata info.
The ABS light goes out when the ABS unit is disconnected which I think rules out a dash to ABS wiring fault so I decided that as it’s a largely self contained system if the feeds/earths were good and wheel sensors OK it must be a problem in the unit. I swapped it for another known good 2nd hand ABS unit and it’s exactly the same.
Does anyone have any ideas? Does anyone have any more accurate pin out data/wiring Diagrams? Should it be possible to get fault codes from this system? Any help would be much appreciated as I'm all out of ideas and going round and round in circles.