hey guys ran into a problem with my 99 s70 turbo (GLT) that's been driving me nuts.

don't know what has happened but i had gotten into my car one afternoon and cranked it, it started roughtly but then stalled right away, if it manages to kick over and stay on it visciously hunts at idle. if i feather the throttle i can get it to even out at normal operating idle, but throttle response is incredibly slow and it misfires at higher rpm (in park or neutral, driving is fine). the ets light (aka the etm in other countries) has illuminated and so has the tcs light which comes on within 5 seconds of starting the car. while driving throttle response is sluggish and is drastically reduced on performance, the wierd thing is if i rev the car and even just slightly touch the brake pedal the revs cut out and the car stalls, i have read this had something to do with the etm being shot. there is some surging and stuttering while driving in excess of speeds of 70kph or roughly 45mpp.
my etm has already been upgraded to the yellow sticker but could this still possible be the etm being shot?

obd codes are as follows : p0118 p0134 and p0103 and a random p0013 that only appeard once and hasn't shown up again. so far i have replaced both the maf sensor and the engine coolant temperature sensor to no avail, car still runs like ****. took it to volvo and they printed me out a list of "apparent" faults. i'm assuming they used VADIS or whatever it is to read them.

these are the faults that are stated as "DTC is found active":

ecm-2000 engine coolant temperature sensor - signal too low
ecm904D ETS warning lamp - information
ecm9540 accelerator pedal position sensor - signal too high (i have had this appear once on my obd reader but this doesnt show up on my obd reader anymore after disconnecting the battery to reset codes)
ecm9540 accelerator pedal sensor power supply - signal too high

all other listed thing have no fault found next to them (including ETM IMM SRS ABS TCM and VGLA) so i assume there isn't anything wrong with them. wierd thing is my obd reader says maf or vaf signal too high but the sheet i recieved says maf sensor is fine?

is my ecu fried, i only just recently replaced the battery in it and opted for the cheaper slightly weaker than recommended battery, could this have any effect in this situation? do i need to replace a wealth of parts just to fix this car? volvo wanted me to return everything back to original condition before they even touch it.

any suggestions? anything i might be missing here?

i really need this car for work and only have 2 weeks to fix it.

cheers guys!

 

come on guys need urgent help here!

 

I don't think the lesser battery would impact that many systems. Probably will just have less cranking power in cold weather. However, stranger things have happened.

Start again with the basics. Check for a crack in the air intake near the MAF. Had a car do lots of crazy engine running speed changes and it was a cracked air intake hose. Was hard to find but once identified, it was easy to duplicate the issue.

 

cheers for the reply, i have checked all pipes and connections to no avail, it still holds it boost fine in a wierd way though, i have an mbc connected set to 13psi, it will boost to 6psi all the way up until 4500rpm and suddenly kick into 13psi and holds it, performance isnt greatly improved when this happens and it still drives really poorly.

when this all happened i was trying to retro fit an 850 turbo maf sensor (i was dumb and a tightass to get the right one from the start), i was told it would work if i had cut the plastic shrouding around the pins so my plug would fit, difference was my plug was a 5 pin and the maf sensor was a 4 pin, but the 5th pin/wire on my plug was non existent so i though it would work fine, pluged it all in and what not and tried to crank it, thats when i got the etm lightand the rest of my codes. put my old maf sensor back in and it was still screwed, could i have blown a fuse? or more seriously blown the ecu somehow? before any of this happened i only had one code and that was p1171 lean condition which is why i attempted a maf replacement.

 

The '99 S70's here have ETC. Have the dealer/mechanic check that. It's a known problem.

 

mine has ETS here in australia, all together the same thing though. i have had the dealer check it out and all they did was run it through diagnostics, they told me from what they can see the ets/etm is fine. ecu isn't signalling any etm faults.

 

ok just pulled out my multimeter and tested afew things, i found my positive battery cable heating up to the point of not being able to touch it, i tightened it abit and it seems to still get hot but not so much now. checked if power was running to the coolant temp sensor and maf sensor and both are being fed power, my speculation is that its feeding them too much power/voltage resulting in signal too high codes. the battery was holding a steady 13.8v whilst the car was running. is it possible to overvolt the electrical componenets in these cars? or even short them enough for the pcm to stop functioning correctly?

 

Your battery cables should not be getting hot while the car is running!! Either you've got a serious short, or the cable itself is undersized, or the cable has corroded internally to the point where it is much smaller diameter.

Of course it is possible to damage the car's control units by applying over-voltage; people do it all the time by improperly jump starting their cars or pulling the battery connection(s) while the engine is running (very bad!).