antera309 3 Posted August 27, 2004 Report Share Posted August 27, 2004 My ABS light is on all the time and VAG-COM has diagnosed it as an ABS pump fault. I tried replacing the brake fluid, but with no success.New replacement pumps cost way too much, so I have sourced a known working 2nd-hand unit.Now I just need to fit the thing. Haynes and Bentley no help whatsoever. Physical replacement doesn't look too difficult, but I have two questions regading discharging/charging the hydraulic system:1) Does the ABS pump have a drain plug or, failing this, is there a way to run the old unit completely dry to avoid massive brake fluid spillage when the brake pipe unions are disconnected? &| 2) With the new ABS pump fitted, I am informed that the normal method of bleeding the system WILL NOT remove all the air from within the ABS pump itself. This page on the VAG-COM website covers some of the special procedure for doing this. However, it doesn't go into enough detail. When the pump is run for 10 secs, does the system need to be open or closed? Does it only need to be done once, or repeated when bleeding from each corner? ?! ?! ?! Has anyone ever replaced a Golf Mk3/Corrado ABS Pump, or have access to a workshop manual that explains how to do it properly?Any help would be greatly appreciated!![ Edited ] Link to post Share on other sites
VR6Pete 1,455 Posted August 28, 2004 Report Share Posted August 28, 2004 I spoke to Vince about this, you DO need to use the VAG COM or the other VW software to bleed the system dry, you will also need to match the pump to your ECU as well, i beleive this is a once only thing.... so I didnt even think about a 2nd hand one. not sure on this tho, just readin me bently manual.... in the end it wasnt my pump at fault, it was a loose diagnostic cable. once corrected, it showed as a sensor fault. Pete Link to post Share on other sites
antera309 3 Posted August 28, 2004 Author Report Share Posted August 28, 2004 Pete, tell me more about this loose diagnostic cable. Which cable was it? Link to post Share on other sites
acf8181 0 Posted August 28, 2004 Report Share Posted August 28, 2004 pete's right...for obd2 you have to match the pump to the ecu and you have to use vag-com for bleeding.if your car is obd1 it may be simpler. Link to post Share on other sites
VR6Pete 1,455 Posted August 28, 2004 Report Share Posted August 28, 2004 it's a grey cable, vince found that mine had become disconnected in the fuse box area. thus giving the impression that the pump/ecu is dead. lukily for me, it wasnt. best of luck Link to post Share on other sites
antera309 3 Posted August 28, 2004 Author Report Share Posted August 28, 2004 So can a 2nd hand replacement pump be matched to the ECU with VAG-COM or has VW built a "We want your money" feature into it that prevents this? Link to post Share on other sites
acf8181 0 Posted August 28, 2004 Report Share Posted August 28, 2004 if they have to matched, surely the cheapest solution is to wait till you find a full vr6 being broken and try and get both the pump and the ecu? Link to post Share on other sites
antera309 3 Posted August 29, 2004 Author Report Share Posted August 29, 2004 I thought of that. If an ECU and Pump can't be re-matched, this is the way to go. Non-VR6 models use the same ABS system, so finding an ECU/Pump pair from a breakers shouldn't be a problem. Link to post Share on other sites
acf8181 0 Posted August 29, 2004 Report Share Posted August 29, 2004 nah...not all non-vr6's are the same system. vr6's have EDL incorporated inthe system, not sure what other models have EDL but i'd imagine only 16v's at best. Link to post Share on other sites
VR6Pete 1,455 Posted August 29, 2004 Report Share Posted August 29, 2004 I nearly bought a ECU/Pump from a guy, parts number matched, apart from that model had been superceeded. it was from a 16v, and it did have EDL, odd! Link to post Share on other sites
acf8181 0 Posted August 29, 2004 Report Share Posted August 29, 2004 not saying gti's don't have EDL...just don't know. i haven't even sat in a gti let alone had a hunt about one. Link to post Share on other sites
antera309 3 Posted September 3, 2004 Author Report Share Posted September 3, 2004 A Teves/04/EDL ABS Pump has 6 outlets, Teves/04 (ABS only) has only 4, so it's easy to tell the difference just by looking at it. Although I'd always play safe and get second hand parts from another Golf VR6 anyway.Here's the full VAG-COM fault code reading from my ABS unit:00276 - ABS Outlet Valve: Left Rear (N136) 35-00 - -00290 - ABS Wheel Speed Sensor: Rear Left (G46) 04-00 - Mechanical Malfunction00287 - ABS Wheel Speed Sensor: Rear Right (G44) 04-00 - Mechanical Malfunction00793 - Brake Pedal Position Sensor (G100) 35-00 - -Looks like my rear sensors are up the creek, with the first code (00276) being related to the ABS Pump unit itself.[ Edited Fri Sep 03 2004, 09:06PM ] Link to post Share on other sites
acf8181 0 Posted September 3, 2004 Report Share Posted September 3, 2004 only thing is you have to remove the pump from the control unit to see how many outlest it has!thats a big list! Link to post Share on other sites
antera309 3 Posted September 5, 2004 Author Report Share Posted September 5, 2004 Could those mechanical sensor errors possibly have been caused by the car being put on the rollers when the Unichip ECU was set up?The only item which constantly re-occurs is the brake padal position sensor one. Checked the wiring to the sensor and this is OK, so a replacement sensor is on the way...[ Edited Sun Sep 05 2004, 01:03PM ] Link to post Share on other sites
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