2004 Volvo S60 Electrical problems ONLY during summer

[hankb]

I just got off the phone with Tony, the tech from XemodeX. It was a great conversation and has left me with great respect for the company. Tony spent time understanding the problem as I've documented it here. He agreed that it was possible that the CEM failure was causing the problem, but he felt like it was more likely to be a relay failure. I _DID_ replace 12 relays (PN 9441461) on the CEM, but not CMA2 and CMA3 (PN 9441158). Tony suggested that one of those could be the culprit and he offered to provide follow up support if replacing those didn't solve the problem.


For posterity - My CEM:

[hankb]

It has been six weeks since my last follow up - the problem has not resolved. Here's a brief recap:

2004 Volvo S60 encounters numerous electronic problems while driving in hot weather including:

• * Sudden jerk while driving as if a brick has been run over.
  * Speedometer and Tachometer click and fall to 0.
  * ABS light comes on
  * Information panel reads "BRAKE FAILURE STOP SAFELY"
  * Air Conditioner stops working
  * Windshield wipers begin running (this has only happened twice and not recently)
  * Drivetrain becomes unresponsive - RPM will increase but transmission is tight and the car lurches very slowly despite power.
  * Gear shift indicator in console does not report the correct position of the gear shifter (i.e. the car is in park but the indicator shows Reverse).

After working with this problem for 4-5 years (and my wife having repeated nightmares about driving the car), I'm getting closer to some solutions.

Here are the remedies I've attempted:

• * Dealership TCM replacement
  * Xemodex ABS module
  * Xemodex CEM rebuild
  * Replacing all relays in the CEM fuse box
  * Soldering crimped connections on the CAN to the CEM.

The ONLY intervention that has shown clear improvement has been removing the trim panel below the steering wheel and running the AC on HIGH into the floor area. Based on this, I'm still confident that the CEM is the problem and I'm re-contacting Xemodex today to ask for a replacement module consistent with their "100% Fix Guarantee"

I'm still eager/desperate for any additional suggestions or potential fixes.

[doublebug]

I would try heat test again.
Get CEM cartridge.
Remove black perforated cover. (see your video about XEMODEX rebuilt CEM. 6th second)
Usually processor and flash are covered by metal cap. If so after rebuild remove it.
Put CEM cartridge back (without covers) and try to heat it in the aria of processor and flash.

BTW is your car FWD or AWD?

[hankb]

It's the humidity, stupid.

I have discovered a very valuable piece of the puzzle toward solving my problem. After getting a replacement CEM from XeMODeX, the problem didn't change. I did purchase a hygrometer and began observing the humidity when the car faults. Here's the thing - the fault ONLY occurs over 60% or so humidity. That's the reason the car drives perfectly all winter long. We had a low humidity week (16%) with high temps (+100 F) and the car didn't fault AT ALL. So, I know the problem is humidity related. I soldered the three CAN splices near the CEM, but they haven't changed the problem - what shall i try next?

I'm actually VERY excited. I've eliminated a lot of potential issues AND figured out how to predict the problems, I'm a little embarrassed it has taken me so long to get this far!

[matthew1]

It's the humidity, stupid.

I have discovered a very valuable piece of the puzzle toward solving my problem. After getting a replacement CEM from XeMODeX, the problem didn't change. I did purchase a hygrometer and began observing the humidity when the car faults.

Excellent problem solving.

[hankb]

I thought it was time for another update. I was curious about the heat generated by the CEM, so I eventually just cut out all of the plastic shielding surrounding the CPU of the CEM until it was exposed. I left the entire CEM assembly hanging in the floorboard and waited for a fault. When one did occur, I felt the heat sync installed by XeMODeX and discovered that it was cool to the touch. CEM heat is not the problem.

I have only had one fault in the past 9 days despite driving in temps from 80F - 105F. The difference is that I'm monitoring the humidity and only engaging the transmission when the humidity is below 40%. I purchased a dehumidifier for my garage today to act as a stopgap while I continue to work on the problem.

This image shows the hygrometer in the dash during the ONLY fault I've had lately.


I believe that I can avoid faults if I run the air conditioner upon starting the car and do not engage the transmission until the humidity falls below 40%. If my memory is accurate, the faults don't occur until the transmission is engaged. My experience also suggests that the fault is inside the cabin since the fault is correlated to humidity levels within the cabin regardless of the outdoor humidity. So, theoretically, if I only engage the transmission when the humidity is below 40%, I may avoid all faults.

My LATEST hypothesis for the faults is corrosion responding to humdity in a bad wire splice (? Better ideas would be appreciated!)

The following image from a high speed CANbus splice came from barrysharp with the accompanying text:

Well, Volvo regional rep said the first thing to try is for technician to ensure the cold soldered module connections are solid - and in fact they should be severed and hard soldered back together. Apparently this has solved the same problem on cars previously exhibiting this type failure. This will take 4 to 5 hours of labor to accomplish.

I assume Service Dept will hand car back to me after doing the hard soldering job and driving car about for several days to ensure there's no repeat of the problem.

Apparently this problem is occurring on the high-speed network and not the low-speed network where I had a similar problem 2 years ago when the whole driver's console display quit. They solved the low-speed problem by hard soldering as well.

This is BarrySharp's example splice.


My next plan is to locate those splices and replace them with solder, or potentially take it to the dealer if I don't find success myself.

I have a 2004 Volvo S60/S80 wiring diagram that I acquired here (alt mirror). I've been through it a bit, but I don't understand if/how it identifies those cold spliced wires, but I'll keep looking and I'd appreciate any help - or someone who is able to tell me where to find them.

[mal0518]

I just bought an '04 last week for my daughter and I am running into the same problems. Most of the instrument panel goes out, the air conditioner quits, and when I stop the car I can't get it into drive. I just started researching this and am finding that the CEM is the most likely culprit. Xemodex has on their website what looks like an improvement to the original which allows it to function much better in hot weather. I don't know what to do. I want to be sure it is the CEM before replacing it but how can you tell? I found out that the previous owner had it checked at a Volvo dealer before trading it in and they diagnosed it with a bad CEM, but I am finding that a lot of these problems are from the DIM. I can't believe there is no recall for this. I am going to file a complaint with the NHTSA and urge everyone else with this problem to do the same.

[mal0518]

This also happened to me again today. Very hot in the car. I was on my way to my mechanic's when I noticed that the instrument panel was out and the air conditioner was blowing warm. When I got there I turned the car off and tried to start it again. No luck. My mechanic could not bring up any codes. I suggested disconnecting and reconnecting the battery, and it started fine. Ok driving back to work with no problems. Just hope it starts when I leave to go home.

[abscate]

I just bought an '04 last week for my daughter and I am running into the same problems. Most of the instrument panel goes out, the air conditioner quits, and when I stop the car I can't get it into drive. I just started researching this and am finding that the CEM is the most likely culprit. Xemodex has on their website what looks like an improvement to the original which allows it to function much better in hot weather. I don't know what to do. I want to be sure it is the CEM before replacing it but how can you tell? I found out that the previous owner had it checked at a Volvo dealer before trading it in and they diagnosed it with a bad CEM, but I am finding that a lot of these problems are from the DIM. I can't believe there is no recall for this. I am going to file a complaint with the NHTSA and urge everyone else with this problem to do the same.

Do you have a lemon law in PA? Any dealer who took a car in with a known problem, and resold it without fixing it, needs to do one thing.

Fix it on their dime. Your NA Volvo office might help you resolve this.

[mal0518]

Thanks for the tip. The dealer is in NY. I did already email him with the problem and he offered to fix it no charge. Whether it is because of the lemon law or out of the goodness of his heart I don't know, but he seemed to sincerely feel bad about it.