Hi,

I have a 2002 S40 (US spec, 1.9T & 5-speed auto trans) with 150,000 miles. I am aware that these cars have had various problems with the automatic transmission and the TCM, but I have read up on those issues and mine seem somewhat different, although the end result may be the same.

Twice, I have been stopped at a light and when I went to accelerate, the transmission has remained in overdrive or 4th resulting in an almost complete failure to move forward. The first time this happened, the transmission downshifted about 5 seconds or so after I pushed the throttle all the way to the floor, but only to 2nd or 3rd, allowing me to move forward. This was accompanied by a slipping clutch odor. The second time, I actually had to stop and reverse because the light was turning red (it was a flashing yellow turn arrow). After doing that, the transmission returned to 1st.

I can't find any reports of a problem like this with the S40.

The other thing I just noticed today is a subtle slipping sensation (not a huge amount, but enough for me as a very nitpick car owner to be concerned about) under HARD acceleration (WOT), about once per gear as far as I could tell.

I have also had two instances of hard "bang" downshifts, but if I remember correctly, both were after I accelerated hard and then lifted my foot off the throttle.

I am the third owner of the car so I do not know if any transmission work has been done in the past. I last serviced the trans about 6 months ago.

A *possibly* related issue I am also having is a light surging/flutter at idle, sometimes. I presume this is a vacuum leak but I have not managed to find it yet.

I have also had multiple instances of the code P0237 - Turbocharger/Supercharger Boost Sensor 'A' Circuit Low. I swapped the two MAP sensors but the code remains the same; however, its appearance is extremely sporadic and never corresponds to any kind of driveability problem.

Does anyone have any ideas about the transmission (and/or the other issues if possible)? I would like to make this car last at least another year before I sell it.

Thanks.

 

It seems likely that the slipping/hesitation under WOT acceleration was a failing coil pack. It completely failed yesterday and I replaced it. The car now accelerates smoothly. However, the strange transmission downshift problem remains. Any thoughts on this would be appreciated.