ABS failure

[Teachrz]

I had the tell-tale "brake failure stop safely" message with the other dash lights and the loss of odometer and cruise control on my 02 xc70 so I ordered a used controller from Erie Vovo. After installing it I still have the same error, but my ABS seems to work (I hit the brakes on a gravel road). Any suggestions?

[JRL]

I had the tell-tale "brake failure stop safely" message with the other dash lights and the loss of odometer and cruise control on my 02 xc70 so I ordered a used controller from Erie Vovo. After installing it I still have the same error, but my ABS seems to work (I hit the brakes on a gravel road). Any suggestions?

Why would you do that?
1st, you REBUILD them, (for $115) you do not buy a used one and (2nd), brake failure message has NOTHING to do with the ABS system....
you totally wasted your money and you also have a much bigger issue, take it to a Volvo dealer and let them READ the codes, don't assume you know what this is, you don't

[Teachrz]

First, I would LOVE to have my ABS controller rebuilt at any cost less than the $997 for a new, but no one currently rebuilds my controller (pn 8671224). Second, I thought it would be a fair assumption, based on a copious amount of internet research, that the "brake failure stop safely" with the ABS, brake, traction control and yellow triangle accompanied by dashes in the trip odometer and loss of cruise contol would in some way be related to the ABS controller.

Is there someone else out there who is a little more collegial and less superior from whom I might get advice?

[JRL]

02 ABS modules rarely fail, you probably have another issue.
Probably just the brake sensor SWITCH that will trigger the light and message.
(I had the SAME THING fail on my 02 S60AWD)

[Teachrz]

Thank you.

[BrownXC70]

I had the same symptoms as you and found that a mouse had chewed through the leads to the RF wheel speed sensor.

[CO8200]

I just started getting the intermittent ABS failure light as well. BBA reman will rebuild the ABS controller, even though it is not one they usually fix for less than $100. The part number of the ABS unit is 4221768. It is on a 2002 XC 70.

CEL codes of P0504, P0571, and then an intermittent code of P2111 w/ limp home.

How do I determine if it is the ABS unit or one of the wheel sensors? Suggestions?

Thanks in advance.

[RockitShip]

...How do I determine if it is the ABS unit or one of the wheel sensors? Suggestions?

I would ask one of the vendors such as Module Masters or BBA, and let them know the codes. They should have a good idea.

[Forkster]

CO8200 - if you read my story from my adventrues last weekend, running low on Voltage in an XC70 will throw a lot of weird codes, including the dashboard failing, limp mode, brake booster failure, ECU failure, ABS failure..etc. Your situation sounds like my trip last week when my car was running out of power because my alternator wasn't strong enough to run my car, and charge the tent trailer I was towing including its battery and fridge. I know you weren't towing anything, but it does sound like its a weird issue.

I would strongly suggest you:
1. Ensure your battery is charging at 100% capacity.
2. Ensure your alternator is working correctly.

Eliminate the simple explainations first, then you're off to figuring out the real issue. Chances are, it's a simple reason.

[CO8200]

I thought a similar thing. The battery with no load registered 12.54v. With the car started and charging it read 14.25v. Seems to be in the acceptable range. I didn't load test the battery, but it appears that the charging and battery are ok.

I reset codes and test drove the car several times today. I have a kiwi wifi setup and the REV app for my iphone so I was able to monitor codes.

Removed the ABS controller. Easy job. Removed the air intake, disonnected the battery, took apart the fuse box, and the three torx E-5 bolts. Covered the valves with plastic and tape.

With the ABS controller removed I was getting P0504, Brake Switch A/B correlation, and P0571 Cruise Control / Brake Switch A Circuit Malfunction, codes on the computer. The ABS and brake lights are on.

Local independent shop indicated that car is fine to drive in this state. No ABS or brake-assisted traction control so be safe on the gravel. Quote from the local shop was that the volume of codes that they pulled with the Volvo tool is typical of a 'zonkie' ABS module. They pulled about 35 codes including CEM-6C46 - Antenna/Light ring Internal Fault and lots of others that don't make any sense. I though low voltage initially, but three techs thought that this pointed to the ABS module. They have done 10 ABS modules on 2002 XC in Boulder Colorado in the past year or so.

BBA Reman indicates that they may be able to fix the ABS module. I will take a $100 bet on BBA. If they can fit the module I can avoid the $1495 price tag on a new one installed.

Will update this when I get news back from BBA.