Volvo s70 GLT code P0243 and its relation to the MAF

skidaddy13 · Post by **skidaddy13** » 14 Jun 2012, 17:36

After having the issue of the car driving fine for a few days then leaving me sitting in the middle of an intersection while restarting it, then back to normal.... I finally ordered a code reader and was able to pull the code P0243 which does not point to the MAF. But that's what all of my research here has led me to. I unplugged the MAF and the car runs fine with not stalling so I hope that is the issue. Before I get a new one I would like to clean this one to see if it makes a difference. I am new to this type of repair so be gentle!

What tool do I need to get the following bolt off with?

It also appears the harness is gunked up as well, could this be the issue? How should I proceed in cleaning the harness? Alcohol and q-tips?

Post by **jimmy57** » 14 Jun 2012, 22:53

Security torx. Pepe Boys and Harbor freight have inexpensive bit sets.

The stuff in the MAF connector is dielectric grease. It should be there to prevent corrosion.

My recollection is the P0243 code is a correlation error code. The MAF signal does not match the TPS input and RPM It can be the wastegate stuck open or busted intercooler or leak in hose from turbo to intercooler or intercooler to throttle.
Potentially a bad MAF but more likely the leaks in turbo to throttle path.
Unplugging MAF stops the MAF from sending the HIGH signal from measuring air that doesn't make to be burned with the fuel injected.

skidaddy13 · Post by **skidaddy13** » 16 Jun 2012, 11:56

That sounds right, so where should I start? please dont say volvo dealership! i want to do this on my own but have very little knowledge...( i did successfully replace the abs unit without issue

)

Post by **jimmy57** » 16 Jun 2012, 12:05

Have an assistant put trans in reverse and hold brake HARD and give it throttle to bring it up to 1800 rpm and you feel around the hoses and listen. If it is a leak it will be obvious. This should be done for 10 seconds with a 90 second or longer idling out of gear between testing periods to keep trans fluid temp from going sky high.
The best would be to take the lower front plastic panel behind bumper off as this prevent you feeling the underside of intercooler and the lower intercooler hose.
Where in TN?

skidaddy13 · Post by **skidaddy13** » 16 Jun 2012, 13:20

Okay I will do this first, hopefully I can find something before taking that panel off. Is it going to hurt anything buy driving it with the maf unplugged to work and back until i get it fixed? maybe 6 mile round trip daily.

Post by **misha** » 16 Jun 2012, 20:11

I just read the code list for p0243 and it says Turbocharger(TC)control valve-signal missing/intermittent fault...signal missing/permanent fault.

Hope it helps.

Post by **misha** » 16 Jun 2012, 20:14

skidaddy13 wrote:...Is it going to hurt anything buy driving it with the maf unplugged to work and back until i get it fixed? maybe 6 mile round trip daily.

It will not hurt anything for a few days,but in a long term it will damage the cat & o2 sensors because the engine will run VERY rich.

Post by **jreed** » 17 Jun 2012, 07:10

I wrote up a quick DIY on removing and cleaning the MAF sensor, including the T-20 security bit required for those bolts here:
https://www.matthewsvolvosite.com/forums ... 1&p=218607

: Torx T-20 hollow tip security bit; IMG_5148.jpg (69.89 KiB) Viewed 3726 times

skidaddy13 · Post by **skidaddy13** » 17 Jun 2012, 12:32

jreed wrote:I wrote up a quick DIY on removing and cleaning the MAF sensor, including the T-20 security bit required for those bolts here:
https://www.matthewsvolvosite.com/forums ... 1&p=218607
IMG_5148.jpg

looks like a great write up, thanks!

skidaddy13 · Post by **skidaddy13** » 17 Jun 2012, 12:33

misha wrote:I just read the code list for p0243 and it says Turbocharger(TC)control valve-signal missing/intermittent fault...signal missing/permanent fault.

Hope it helps.

it would if i knew where that was located and what i should do next

i need pictures and flow charts