2004 Xc70 cross county

Alex5150 · Post by **Alex5150** » 15 Jun 2021, 20:42

My volvo seems to do this only when its very hot outside .105 last time today it was 110. .my volvo makes a thump under the car sounds like the tranny ..then shuts off ..then comes back on again..but instead of having everything working normal .i have no lites no power .windows etc.and it runs like its running on only a few cylinders weak.. Someone told me it was limp mode .anyway it got me home .it flickers back and forth.but everytime it does it makes a big thump. Does anbody know what the problem is.

Post by **jonesg** » 16 Jun 2021, 03:43

make sure the cooling fan is working in the computer box next to the steering fluid reservoir.
Air is supplied from the cabin so it helps to have the A/C turned on to cool the computer.

motormikeyman · Post by **motormikeyman** » 17 Jun 2021, 10:56

You are probably experiencing a heat related CEM failure. You may hear relays on it clicking when this failure occurs, it is under the dash above your left foot. Clunk in trans feels like you are running over a brick, transmission goes into limp home mode, stalls- no start condition, no tach or speedo, ABS failure warning, no sunroof or power windows, no AC. Xemodex has a good diagnostic procedures for this issue on their website.

Alex5150 · Post by **Alex5150** » 20 Jun 2021, 12:12

Thanks for your advice ..

Post by **oragex** » 20 Jun 2021, 14:34

Second the CEM failure, but first measure your battery and check all connections. You can look at the CEM with a flash light from under the dash for dry traces of leaks, or remove for further inspection if you can lift the wiper arms

Post by **abscate** » 21 Jun 2021, 04:43

Ten 2004 was known for a heat soak problem in the CEM. Thread maybe 2 years back?