Radiator anti tamper device charging failure, lost communication with starter/generator volvo xc70 3.2 2010

Dcadizel · Post by **Dcadizel** » 22 Jan 2025, 09:49

Does any one has experience with RATD ( radiator anti tamper device? I’ve replaced the device already. Also replaced alternator with correct one, and regulator. Permament codes cleared up in ECM but it still shows me U012000 „lost communication with starter/generator control module. Car is charging and voltage stays around 14.5. The message „charging failure, service urgent” comes and goes. Did test drive and car runs normally but when iddle there is small flickering of light from time to time. I susspect RATD is causing it. Did anyone experienced issues with RATD? I drive xc70 3.2 2010

Post by **xHeart** » 23 Jan 2025, 14:41

Dcadizel wrote: 22 Jan 2025, 09:49 Does any one has experience with RATD ( radiator anti tamper device? I’ve replaced the device already. Also replaced alternator with correct one, and regulator. Permament codes cleared up in ECM but it still shows me U012000 „lost communication with starter/generator control module. Car is charging and voltage stays around 14.5. The message „charging failure, service urgent” comes and goes. Did test drive and car runs normally but when iddle there is small flickering of light from time to time. I susspect RATD is causing it. Did anyone experienced issues with RATD? I drive xc70 3.2 2010

You may still have a failing or incorrect pulley type on alternator.

Dcadizel · Post by **Dcadizel** » 28 Jan 2025, 17:51

I should’ve mentioned that. Yes, I checked pulleys, the alternator comes with new and it compensates as it should, the otber one that is connected by rubber belt coupling is tight, does not spin at all, it’s tight, also serpentine belt is moving as it should, the compensator pulley was replaced about 3 years ago. I does charge, and I have 14.5 when car is running but I noticed last week that cab light flickered few times. Vida did not show fluctuation but then in the cargo area I have 12v socket with voltage meter and voltage drops to 12.3v for split of sec every minute or so. I started to think the ACM (alternator control module) which is the voltage regulator that came with the alternator is faulty. It is a rebuilt alternator from FCP so i started to suspect somebody messed up…

giegaand1 · Post by **giegaand1** » 08 Sep 2025, 03:24

Hello, i have simillar issue, i have error code ecm-u028600 lost coms with anti tamper device and randomly popping out error in dash about charging. How did you solve your problem?