2001 S60 lower modules dont communicate.

BigChungus · Post by **BigChungus** » 06 Nov 2021, 23:48

TL:DR AT THE BOTTOM OF THE POST

FIXED: IT WAS THE RADIO THAT WAS SHORTING THE CAN NETWORK

My alternator failed and I had to get it towed to the end of my street. Pulled the battery out, charged it and got it up my driveway and let it sit until I got a replacement alternator. After a few broken knuckles I got it installed. Success! It worked! Battery was charging but the entire DIM was no longer working outside of the CEL.

Radio, turn signal, high beams, or locking or opening the trunk with the key no longer work. I've checked the cargo compartment distribution box that powers modules directly from the battery and all fuses passed a continuity test. I've checked major fuses in the interior and all seem fine as well as relays and fuses in the engine bay. I have not looked at the fuses in the REM but will tomorrow. The CCM also is permanently powered on regardless if the key is in. I'm at a loss. Can a module fail and cause all other modules down the line to lose communication? Is this a CAN-L issue? What should I look at or test?

TL:DR majority of modules except passed the CEM are no longer communicating after alternator install.

Post by **abscate** » 07 Nov 2021, 05:57

Given the nature of the comm link, a module failure can indeed take out thing so down stream. I guess you have a wiring break and the looms near the alternator would be a good starting point

BigChungus · Post by **BigChungus** » 07 Nov 2021, 13:02

Checked all the wiring today and continuity tested most of the wires that managed the CAN-L and CAN-H system in the ECM AND TCM running out of the loom as well as checked the plugs for corrosion and found a small amount in the fuse box in the engine bay. Going to take clean that up and check the CEM for any corroded connections. Will update later.

BigChungus · Post by **BigChungus** » 08 Nov 2021, 16:56

I FIXED THE PROBLEM! The whole time it was the radio. Started to get desperate and started removing parts from the car and turning it over to see if anything would change.

Well after removing the dash cluster and the radio the car came to life as I would expect it. Strangely all the information panels on the cluster(time and warning panel) were not lighting up. Replaced the bulbs and that seemed to fix it! Put a junkyard radio in and it works just fine. Now I am debating on if I should get the radio synchronized or to leave it. Cheers!

Post by **jonesg** » 08 Nov 2021, 21:51

If that was my car it would be at the junkyard by now.
anything beyond a fuse is fatal.

Post by **abscate** » 09 Nov 2021, 00:03

I wish we would just stop these busses at the border. All they do is bring in problems from Canada, eh?

BigChungus · Post by **BigChungus** » 09 Nov 2021, 15:44

jonesg wrote: ↑08 Nov 2021, 21:51 If that was my car it would be at the junkyard by now.
anything beyond a fuse is fatal.

I was pretty damn close. For such an old car if any major module went out I would have thrown in the towel and called pick n' pull.

I coincidentally was working on the radio a week ago because it lit up but had no sound anymore. Replaced the internal amplifier and still had no luck. I eventually re-flowed the solder joints on the chips for my radio to hope it was a cracked solder joint and then put it in an ultrasonic cleaner to remove the flux(VERY bad idea) and I must have made the through-hole capacitors and carbon through-hole resistors a ticking time bomb. I imagine they began to degrade for a few days after I did it. The timing with the alternator and the radio going out was a very unlucky coincidence. I might get drastic for fun and remove the chips that identify with my car in the radio and re-solder them on another board of the same model and revision. Assuming a voltage main didn't get shorted into a data line into the chip, then I guess its game over.