ABS issues, bad ABS pump methinks...

sak54757 · Post by **sak54757** » 27 Dec 2019, 11:38

Hi all,
on my 2001 xc70 185,000 miles: recently had the ABS lights, along with the dire warning of brake failure, pull over asap!! The code was CEM-1A5F
The first thing i checked was the 5amp fuse and it was blown, replaced it and it blew again (hey, i can hope it was just an old fuse...) took a good look at the module and noticed the wires to the pump had melted insulation. unplugged the pump, put in a new fuse and this time, while still getting the idiot lights and warning message, it didn't blow the fuse, so, bad pump, right?
I cannot find a source for a new one (Part 9467586) anyone know where to get one? Hat to put a used one on....

Post by **oragex** » 27 Dec 2019, 14:31

Used should be fine.. these don't go bad that often and I think you can use one from any model year. May even look inside the used one to see how worn are the brushes. I'm guessing Volvo is selling the whole unit only for a mere $1500
What I wonder is why did the wires melt in the first place..could it be water got past the small pump seal and shorted something inside?
#5 https://www.volvopartswebstore.com/show ... evel=24650

sak54757 · Post by **sak54757** » 28 Dec 2019, 06:50

oragex
Haven't found a new one that didn't require a bank loan to get, so i'll scout out a used one. Weird thing is that no codes for the pump motor itself were thrown, put it obviously had issues. I'd take it apart and check brushes but we are on the road.... Thanks for your input!

lawrencium265 · Post by **lawrencium265** » 30 Dec 2019, 19:45

You can rebuild these pumps very easily.
Here is a guide on it, it's for a mercedes benz, but it's the exact same motor.
http://www.mercedesmedic.com/abspumprepair/

You can buy the bearing at Fastenal in the u.s. For $1.99, they had them in stock at my local store Part# 0474374 or 6001-ZZ
The brushes are 12mm x 5mm x 5mm
I found that my bearing had locked up completely and the brushes were worn.
be very careful removing the motor, if you pull out the cap on the end of the motor then you will have to pull the plugs out of the side of the abs block to reinstall it because it is retaining two spring loaded pistons, then you will have to bleed the entire system (ask me how I know)

sak54757 · Post by **sak54757** » 30 Dec 2019, 21:47

Thanks for the info, good to see the age of the back yard mechanic is not gone, $20 vs $$$$$$$, I'll give it a go!

sak54757 · Post by **sak54757** » 01 Jan 2020, 15:04

Alas, the reasonable priced repair didn't work. Redid the motor, got it off and on (without dislodging the little cup, phew!) but all the dash lights promising the end of the world as we know it and the cem-1a5f, cem-510f and, of course the cem-1a59 codes are still there...Xmodex time?

Post by **oragex** » 01 Jan 2020, 15:48

I would try pulling the whole electronic module at the junkyard, the connector is a bit tricky, but worth a try. Perhaps if the year and the numbers match - also the STD vs DSTC. Don't have to disconnect the fluid lines, I think there's a video on youtube

sak54757 · Post by **sak54757** » 01 Jan 2020, 16:02

unfortunately we are in a desert of 2001 xc70's, not one junkyard in 100 miles has one and i know the module is specific to the xc's. I am rapidly approaching the point where the car needs me more than i need it...
Thanks for the suggestion, and yes, the connector is great fun to remove!

Post by **oragex** » 01 Jan 2020, 18:05

Some TV shops will carry such repairs for not much. Usually it needs a chip reflow and replace a few resistors
Ebay also has these repair services - example https://www.ebay.com/itm/ECU-ECM-BCM-Co ... Swf29cReoj
A BCM DIY repair viewtopic.php?t=12651

lawrencium265 · Post by **lawrencium265** » 01 Jan 2020, 22:10

Doing the opening and reflow of the module is fairly easy as well. when I pulled my connector off to do that job there was green corrosion on some of the terminals.

There are two fuses under the hood for the abs (#14 & #19) in addition to #9 inside the car, so you should check those as well.