2004 S60 Troubleshoot heat soak ECM, BCM, CEM, & TCM Topic is solved

Post by **oragex** » 07 Jun 2015, 10:56

That's great news. Were there any humidity/water traces at the bottom of the ECU box?

Post by **abscate** » 08 Jun 2015, 07:34

Mod note

Linked to original discussion
Locked original discussion
Submitted to VRD for archive

hankb · Post by **hankb** » 08 Jun 2015, 07:42

oragex wrote:That's great news. Were there any humidity/water traces at the bottom of the ECU box?

No. I didn't see any evidence of water or humidity anywhere.

Post by **abscate** » 08 Jun 2015, 10:28

Hank - thanks for seeing this one through - these problems are the kind that drive you crazy, and kill otherwise good cars. If you want to add anything to the locked thread to fill in/complete just let me know and Ill unlock or edit.

Glad you got to the bottom of it - now go drive your car and ENJOY IT!!

mjtgch · Post by **mjtgch** » 13 Jun 2015, 10:14

I've been having the same problem with my ECM. Getting "Reduced Engine Performance" and "Check Engine" light. I found corrosion on the ECM pins and had to clean them with a sand disk on my dremel. For the female, I used a small paper clip, straightened it out, scored the sides with a knife, sanded the tip to a point with a grinder and then attached it to a high speed drill and drilled out and polished each hole. Not every hole has a connector. Sprayed Inox lubricant and moisture barrier to pins and holes and reinstalled. Still did not completely solve the problem. Then, after a series of faults while driving on the highway, and using a Bluetooth OBDII to reset while driving, I had the need to crank up the AC with the fan on high. Miraculously, the problem did not recur. So, I pulled the cabin air filter only to find that it was pretty clogged and meticulously vacuumed each fold. Then I removed the cold box fan and with both suction and blower attached to the duct that pulls air from the passenger cabin. Reassembled and reinstalled everything. So far, so good. That cabin filter had not been changed in a year and a half and the small fan at the cold box is not strong enough to pull cool cabin air if the system is moderately to heavily clogged. Being somewhat of a computer nerd, I deduced that there was some sort of thermal protection at the cold box that was shutting down the ECM to prevent heat damage.

mjtgch · Post by **mjtgch** » 13 Jun 2015, 13:08

Now, after driving the car a couple of hours today, with absolutely no faults, when I got home tested the engine compartment temperature to the eBox temperature. Huge difference. 180 ~ 200 degrees compared to 120 degrees. I think we have the culprit. Also, the scant airflow from the poorly designed ebox fan is suspect in the formation of moisture that caused the corrosion on the ECM pins. Wondering if a replacement fan would not be beefed up to compensate for the weaker OEM? Then, for extra credit I went out and bought some DeoxIT. Great stuff, It really cleaned a lot of the corrosion I was not able to get at. Guys at Volvo were trying to use my problem to get me to trade up. Now I'll sell my car privately, not feel guilty that I sold a problem to an unsuspecting buyer, get more money and get a great deal NOT at a Volvo dealership.

mjtgch · Post by **mjtgch** » 13 Jun 2015, 13:21

Incidentally, the ECM removal tool was something I initially borrowed from a worker at a Volvo dealership. It resembles a barbeque tong. So, I made a template using the original out of a manila folder, found a barbeque tong that came close to the size (thickness of metal most important), utilized my HS metal-shop training and made a working tool. Took about 45 minutes for the template and an hour to fashion the tool. Works great!

c70-ed · Post by **c70-ed** » 27 Jul 2015, 13:58

hankb,
Have your issues stayed away? Your symptoms appear to be similar to mine. I have an 07 C70. I bought it this spring and had no issues for the first couple of months. As temps and humidity rose I started to have the intermittent electrical issues. Before I spend lots of money with xemodex, I plan on trying DeoxIt on all the CAN bus module connections I can get to. Thanks,
Ed

hankb · Post by **hankb** » 27 Jul 2015, 14:42

I am happy to report that the DeOxit was a complete fix. After thousands of dollars in parts and hours of digging - that was the solution for me. The car hasn't acted up at all since I sprayed the Deoxit.

c70-ed · Post by **c70-ed** » 27 Jul 2015, 14:55

Thanks for the quick reply. I'm going to pick up some Deoxit on the way home from work.

Edit: Done. I must say the access to the ECU and TCM and removal of the harnesses on the 07 C70 couldn't have been easier. The modules stayed mounted and the harnesses come off with just the push of the levers that are part of the plugs. 10 minute job, with half of that letting the car sit after removing the negative battery cable.

I sprayed both sides of the connection with the deoxit and worked the connections on and of a few times. I repeated that sequence and then used compressed air to blow out the excess deoxit. The car works fine now, but all that tells me is that I at least didn't screw anything up. Only time will tell if that cured my problem. If not, I'll move on to other modules on the CAN Bus and repeat. I'll report back in a couple of weeks if the issues are cured, sooner if not

2004 S60 Troubleshoot heat soak ECM, BCM, CEM, & TCM Topic is solved

Re: 2004 S60 Electrical problem between ECM, BCM, CEM, & TCM