Brake/ABS/Bat lights on. 2001 V70t5

thorv70t5 · Post by **thorv70t5** » 03 Sep 2022, 00:22

Drove car and the Brake light, ABS light, Battery light came on. Also got message "brake failure Service urgent" see pictures.
Drove car home parked it and next morning it was dead with no battery power. Put a Battery Charger to the battery for 12 hours, tried to start car but dead.

Any suggestion to what the cause could be?

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Post by **jonesg** » 03 Sep 2022, 03:17

Did you disconnect the battery to charge it, I guess not.
If it takes a charge when disconnected then theres a short in...maybe the brake controller or abs motor.

You can try pulling that fuse and see if it parasitic draw goes away, directing you where the problem is.
Problems with the abs pump can trigger false codes down the line such as fuel pressure sensor.

try a parasitic draw test and pull fuse 9 in the passenger's compartment panel it's for the ABS module, disconnect and see what errors come up and test driveability.

It would help if you read the codes too.

thorv70t5 · Post by **thorv70t5** » 03 Sep 2022, 16:23

Battery did not charge while connected yesterday, as you said I now disconnected the battery and now charging it. will give it a while to see if it will take the charge........... currently out of town and will look into it closer with pulling CBs and see if any codes is stored.

thorv70t5 · Post by **thorv70t5** » 23 Sep 2022, 09:22

Solved.
Ok, following up to my original post.
I had another charger to charge the battery while disconnected and it took a full charge. Battery ok. Connected the battery to connectors, car started fine now I had the bat light and a message “el system over voltage”. After a little while it turned into the message on picture above. I put a voltmeter on the battery while running at idle and it was 16-17 volts. This scenario led me to the voltage regulator gone bad.
Car sat overnight and tried to start it again battery was now dead again. Went to a Junkyard and found an alternator from a 06 XC90 for 37$ with a 10$ core refund. Installed it in my car and all warning lights and messages gone. Battery still good after it sat overnight. Must have been a short/bad voltage regulator. (The messages had me going in a different direction though originally with the ABS module etc.)
All good now though!

Post by **jonesg** » 24 Sep 2022, 02:10

2 minutes with the voltmeter told you all you needed to know.