hi, i have a 2004 volvo s60 2.4l (standard). i have a 15 mile commute to my job from where i live. last summer my car made a thud like the brakes would grab the calipers and the all the electronics would go dead, when it turned the car back on i would get an srs airbag service urgent the check engine light would come on. ( little bit more detail sometimes the thud will come and all of the electronics will dim but than come back. and sometimes they i will get a brake failure light and everything dies, except the engine.) so i took it into the dealer once and they didnt really have any idea. so they cleared the codes and sent me on my merry way, well the next day it happened again. they ended up narrowing down to something with one of the posts on an engine mount shorting out or something. so i took my car back worked great for the rest of the summer all winter and now this summer im having the same issue. i cleaned the battery posts and connections . as well as the positive connections near the fuse box. im kind of lost as what to do next. anyone else have a similar issue???? and how they fixed it.

 

I have a 2004 S60 2.5T doing the same thing. Hot, humid days I can get about 5-10 miles out of it before the clock goes to dashes, relays behind the dash click, all gauges and dash go dead and the car goes into the "limp home mode". Sometimes it will set the CEL and the SRS Airbag light is set. I've also seen the "brake fluid low" message, and "brakes failed, stop safely" message but these are intermittent and do not happen in conjunction with the dash blanking. When the dash goes blank I also lose power to the power windows and locks unitl the car sits and cools down. I've had the car since new and all of the recals are complied with that I know of including the fuel psi sensor, module software updates, etc. It is a temperature related, wiring/circuit board issue. I'm leaning toward the Autobrake Control Module but haven't spent the $$ yet. I haven't found any forum that gives a definite fix for the issue but have found several posts with the same issue, included the NHTSA site. Any insight would be appreciated.

 

Hi,
probably you have a faulty Cluster Instrument... Common problem.

 

You may be right...I actually had the DIM module out and apart. It is an different version from the 03 and older S60 models but similar. The main difference(should have taken pictures) is the voltage regulator chip L4925N, no longer has a heat sink but uses the board as a heat sink. The body of the chip is soldered to the board! I've seen in other forums where reflowing the Motorola CPU chip and applying a heat sink to the CPU have solved the older version of the dash blanking issues. I did the reflow to both the Motorola chip and L4925N chip and thought I had the issue fixed but the problems came back after a week.