ABS Fault

I've got an 2002 Royale XL2 with ABS and the ABS idiot light, red warning light in the front electrical bay as well as the diagnostic display on the dash saying there is a ABS fault. Faults reads "retarter shorted to 12V". The repair shop says to make the situation to go away, I must replace the ABS ECU in the electrical bay at a cost of $1200. Anyone have experience with this system?

Gary Swaim
2002 Royale

I am curious as to which shop told you this, and whether they have experience with Prevost vehicles. The retarder input to the ABS system is via a relay, like most things in Prevost's design. If you doubt the voice that told you this, I would try inspecting the relays in the front junction panel (one for Trans and one for Engine) and make sure wire scraps did not get behind the relay bases, as well, check the relays. if the surge suppression diode in one of the relays shorted out, then you could have that indication back to the ABS ECU. Let me know what you find. Thanks.

I've had an " ABS" warning light in dash light up the first trip I took in my 2005 H3 Liberty. It came and went without warning for a week. Gone another 5,000 miles on various trips since and nary a thing. No ABS warning light etc. and all is well. Gremlins.

FWIW dampness, such as driving for the first time after the bus has driven in the rain, or just as the result of a wet day my ABS light will come on. Almost always after driving for a while, possibly because I am getting the brakes warm I can stop, turn off the key, restart and no more light.

I learned a long time ago it is a waste of time to chase an intermittent problem.

I was at Prevost in New Jersey on Tuesday and they did some work on the coach, when I was preparing to leave the ABS light was on after starting (never happened before) I asked the tech about it and he said it is normal and will go off after you hit 5 miles per hour. He was right.

Settin at Prevost, Nashville waiting for my appointment in the morning. GOing to have them look at the ABS fault I've had ever since owning this bus (4 months). Any suggestions as to how to approiach this problem? I'm tired of reading the Pro-driver everytime I start the bus and it says check brakes.

They hooked up the computer to the bus and found the same fault code I gave them from the Pro driver readout (127 I) That equats to a power failure in the ABS system so they pulled the relay and the code didn't clear. Replaced the ABS ECU and reinstalled the relay and the code cleared and fault disappeared after a short drive. Looks like I need to find a ABS ECU since they want over a $1000 for one here. I checked Buddy Gregg and my wholesale price was about $750 for the ECU. I'm thinking there has to be a wrecked Prevost XLII out there just begging for me to have the ABS ECU. Any ideas where?