My wife called me this afternoon to say that the "ABS Brake Failure Stop Safely ASAP" light was on in our 99 S80. She also said that all the gauges had stoped working but that the car otherwise seemed to be driving fine. She managed to get home thankfully, but she said this was issue was happening on and off the entire way home (+/- 1 hour drive).

I just went out to check things out. I got the same error right after startup and here'made the following observations:

All gauges except the fuel gauge stop working when this message comes up. Evey light on the dash becomes illuminated also. At first the car seemed to drive just fine despite the light show.

When the error is up the gear shift selector lights don't change when you shift gears (e.g. the car reads as being in "Park" when you're in Drive)

The door lock/unlock controls on the FOB work, but the lock/unlock control on the door only locked the door - it wouldn't unlock them.

One time this evening after turning the car off I heard a weird chattering sound coming from within the engine compartment by the drivers side wheel well. It only lasted a half second or so, but I've never heard it before. Sort of sounded like a pi**ed off chipmunk (yes, I'm being serious - sounded almost exactly the same).

Toward the end of my 'tinkering" I found that if I turned off the car it wouldn't restart until after I waited a few minutes. It would just crank endlessley without starting.

Pulling the ABS fuse had no affect (didn't think it would)

Jockying the ignition/keys had no affect

Battery power seems fine, no dimmed lights or slow cranking noticed. Seemingly plenty of juice.

I played with the car for about 20 minutes and the issue seems to be getting progressively worse. On my last drive the engine RPM's were quite high at first (I'd guess about 1500 RPM at 'idle') and then the engine started running very rough as though it was misfiring. At this point I thought I ought to stop, regroup, and get some advice.

I did go to a garage a few weeks ago regarding some check engine lights and they said there was a fault code indicating possible problems with the Electronic Throttle Control Module. They reset it to see whether the light would come back on. The light did come on, but the car has been running just fine up until today.

Hooked up my OBDII and came up with code indicating a major evaporation system leak.

Any thoughts or advice would be really appreciated! I suspect it may be the electronic throttle control module but I'm not totally sure. Whats a replacement module cost (just the part)?

 

I'm guessing that your ABS module is shot at a minimum, not that uncommon for the early S80s.

 

Well, I made it to work without the brake warning coming up today, but I did get a new message saying "Transmission - fix at next service". I also pulled three new codes:

P1630, P1631, P1633

I'm guessing whatever is wrong is causing the computer to go haywire and throw all kinds of error messages...

Is there any way to test the ABS module at home using an ohm meter or something similar?

 

This is what I went through back in Oct 2010: skip to the end
https://volvoforums.com/forum/showth...ighlight=P1633

 

Thanks for the link. I'm going to try and clean the throttle body tonight and hope that helps.

When I left work tonight the Brake Failure warning popped up as soon as I turned the key in the ignition (before the car was started) even though it wasn't on when I got to work. Kinda weird... When I tried to start the car it just turned over but never started. I tinkered with things for a while and tried a few more times but no luck. Now I'm no fan of being stranded with no vehicle anywhere, but being stranded at work is definitely not fun! Luckily I had a pair of pliers with me so I disconnected the Negative battery terminal and grounded it out for a while. Afterwards the car started up no problem and ran great the entire way home (no error codes popped up). Hopefully I can limp it back and forth tomorrow until I can get a chance to work on it.

I'm hoping to get lucky with cleaning the throttle body this weekend. If that doesn't work I'm going to try and send out the ABS unit to have it checked.

If anyone else has ideas please let me know. Electronics is not my strong point.