I'll try to keep my problem brief - I beg you to offer your help if you can help resolve this problem.

I have a 2004 Volvo S60. It has 127k miles. The car is generally fine, except it has bouts of violent jerking while driving followed by other symptoms. Here are the facts:

• While driving the car jerks violently, almost like I've run over a tire tread or something. The same condition recently happened while the car was idling (no jerk, only an audible "click"). I can't find any consistent related factors except it seems to be hot-heat related. The other issues are related:
• The interior lights usually come on
• The instrument panel goes completely blank
• The windshield wipers make one wipe
• The "Rear passenger door open" warning comes on
• The "Brake Failure Stop Safely" warning comes on

Not all of these symptoms occur each time. There are more severe and less severe incidents.

Putting the car in neutral and shutting it off then restarting will clear the issues. If the panel goes out and I don't restart the car soon, the engine temperature gets very high.

I took the car to the Volvo Dealership and they claimed the car had three pages of codes and the TCM wasn't responding at all (not sure i believe them). They installed a new TCM and TCM harness for $1253, but the problem has not changed. Here are the technician notes:

"C/S ON HEAVY ACCEL THE DISPLAY PANEL BLOCKS OUT. CAR JERKS LIKE IT CUTTING OUT. WORSE IN HOT WEATHER. FOUND NUMEROUS TROUBLE CODES. CHECK TCM. FOUND NO COMMUNICATION WITH CAR. REPLACED TCM AND WIRING HARNESS. DOWNLOADED SOFTWARE ALL OK AT THIS TIME."

I have a PPC Diagnostic System hand scanner by BSR (www.ppc-diagnos.com) and it only shows code ECM4340 (fuel tank cover, lock, signal missing).

The VIN is YV1RS61T7423#####

I will gladly answer any questions that might help understand this problem.

I was able to get a crappy video of the problem today- here it is on youtube - http://www.youtube.com/watch?v=gySnZU0aVTA (last 4 seconds)

Thanks in advance.
-hank

 

The wiring harness too, that sounds odd.

It looks to be non-turbo, so I do not think this may be engine related. Possibly a transmission issue. You should have it scanned again, sorry, but by Volvo. You should probably go back there and complain.

 

I have a friend I'm trying to help that has almost the exact same problem. He has a Turbo S60 though.

It almost seems the the main relay is switching off and then back on again while going down the road. It's like the TCM looses electric power, releases the torque converter and then regains power and locks it back up causing the voilent jerk.

I looked at the wiring diagram and it looks like the main relay is controlled by the iginition switch and not a computer.

 

I still have the S60 and I haven't had this problem in about 6 months (I am frankly a little superstitious even talking about it!) - I left the car at Darrel Waltrip Volvo in Franklin, Tn for eight weeks (I wasn't driving it, and they were wonderful - would recommend). They did replicate the error at least once, but could not provide an accurate diagnosis because it was so unpredictable. I think they replaced the computer housing under the hood (sorry I don't recall the correct name).

At any rate, it drove fine for a few months and began doing the SAME thing again. It re-occured about six times in the span of a week. One afternoon while I was contemplating it, I opened the box containing the control module and just wiggled/reseated the module. To my surprise, it hasn't happened again since... even so, like I said, I'm still a little superstitious about it.

So - I don't know if it will have any bearing on anyone else, but my resolution seems to have been to reseat the computer control module located under the hood.