# MkIV: ABS Light ON After Brake Job, VAG-COM: Hydraulic Pump Implausible Signal Intermittent



## firstorbit84 (Feb 25, 2006)

REPOST:The MkIV Forum guys don't care unless the thread has pictures of new body kits and lowering springs, so.....
I did a full brake job with new pads and rotors and a bleed at a small local car club meet last month. The pedal felt kinda soft after leaving, but the brakes grabbed pretty well so I wasn't concerned.
About 50-75 miles and two days later the ABS light comes on while driving around town. Now it comes on within a minute of moving the car every single time I drive it. However, if I just sit there it will take much longer to come on.
I brought it back to the guy's house where we did the brake job and we scanned it and VAG-COM said, "ABS Hydraulic Pump, Implausible Signal - Intermittent." We were recommended to bleed the ABS pump, following the Ross Tech procedure. However, the procedure on Ross-Tech's site doesn't say what to do after you push "Go!" and the on-screen instructions were not very helpful, so after a while it would just say "N/A" all the way across...
After searching, it seems like I may not have been holding the pedal down long enough??? I saw another thread that said you have to hold it down for a while until the pump comes on.
Do you think that bleeding the ABS pump should take care of this issue?? Is there some way to check the signal other than Vag-COM???


----------



## firstorbit84 (Feb 25, 2006)

*Re: MkIV: ABS Light ON After Brake Job, VAG-COM: Hydraulic Pump Implausi ... (firstorbit84)*

bump


----------



## jermarlang (Mar 26, 2000)

*Re: MkIV: ABS Light ON After Brake Job, VAG-COM: Hydraulic Pump Implausi ... (firstorbit84)*

I have not had an issue with the ABS light, but I have had issues with the ABS pump. After going to a few "Tuner Shops"for a brake fluid change, I still had a spongy brake pedal because of air in the ABS pump. For me, the only cure was to let the dealer replace the brake fluid. Their computer opens the pump for complete bleeding. Now I have a firm pedal.


----------



## firstorbit84 (Feb 25, 2006)

*Re: MkIV: ABS Light ON After Brake Job, VAG-COM: Hydraulic Pump Implausi ... (jermarlang)*


_Quote, originally posted by *jermarlang* »_I have not had an issue with the ABS light, but I have had issues with the ABS pump. After going to a few "Tuner Shops"for a brake fluid change, I still had a spongy brake pedal because of air in the ABS pump. For me, the only cure was to let the dealer replace the brake fluid. Their computer opens the pump for complete bleeding. Now I have a firm pedal.

Thanks for the info. So the ABS light went out after the ABS pump was bled at the dealer?? Without having to replace the pump??
If that's the case, I really hope it will work for me too. BTW, you don't have to go to the dealer for this procedure. Anyone with a VAG-COM can bleed the pump, however the on-screen instructions are a little vague, and I didn't get it to work the first time, but I'm going to try again shortly.


----------



## firstorbit84 (Feb 25, 2006)

update: pulled the fuse as described in another thread, and it hasn't come back on since


----------

