Engine surge with torque converter unlocking

jclipper7 · Post by **jclipper7** » 04 Nov 2010, 18:24

Hey all, I have a 03 V70 2.4t that has an engine surge problem (or a torque converter surge). When I'm cruising around 40-45 mph the engine surges about 200 rpm and it feels like the torque converter is unlocking. It does this at most for a couple of seconds and then returns to normal. It cycles like this as long as I'm on the accelerator just maintaining speed. If I let off there are no problems. If i gas it to accelerate it usually un-locks the converter and does fine. If I set the cruise control while this is occuring it goes away.

My first guess is the accelerator pedal position sensor, but I've read alot about the ETM problems on this sight. Does the ETM problem apply to '03 volvos? Has anybody else had this problem? Any tips from you experts? Thanks all. -John

jda2000 · Post by **jda2000** » 05 Nov 2010, 07:49

The ETM issue is for '99-'02.

Try cleaning the ETM.

Post by **mikealder** » 05 Nov 2010, 07:58

Sounds more like the autobox is at fault rather than the ETM, start by checking the transmission fluid level after a decent run using the hot side of the dip stick, also wipe the dip stick on a clean white tissue to see the colour, is it dark brown/ black or red. One option is to flush the box with fresh oil, there are plenty of posts explaining how to do this but make sure you use the correct oil otherwise the box will be ruined in very short order - Mike

jclipper7 · Post by **jclipper7** » 15 Dec 2010, 11:19

Just an update. I removed and cleaned the ETM (throttle side and electronic side). It did not look that bad but I did get a little gunk from around the throttle plate. I also removed and inpected the pedal position sensor, and from the looks of it it would be a slim chance that this is the problem unless it's a wire, voltage, or resistance to ground issue (see my reply to "engine surge and code PL00220"). The trans level is and has been good since the problem started. The ATF is a little dark but still red tinted (not the burnt brown color). The problem still persists. I haven't done the drain and fill flush method yet but intend to. I will update again after that.

Anybody know of any Trans control computer problems or updates/fixes (I haven't seen any)?
-John

jjaV70T · Post by **jjaV70T** » 18 Dec 2010, 16:55

I have a V702.4T and changed the ATF mobil 3309, at 92K this surge started after ..took it in to the Dealer and $175.00 later a 'software upgrade' works fine,, hope this helps..ja

skeeter123 · Post by **skeeter123** » 22 Dec 2010, 08:42

Does it seem to do it when you go over bumps? On my other (non-Volvo) car I had the same unlocking torque converter symptom, turned out that the brake switch (mounted against the brake pedal to detect when brakes are applied) was out of adjustment and would trigger the torque converter to unlock when I went over bumps in the road. Try putting your foot under the brake pedal and pulling up on it, see if that stops it from happening. If so, try removing/cleaning the brake switch.
Hope this helps.