Off Topic - My Saab 95 / Map Sensor
Turbo Mini Forums

Sorry for the non mini based question but i know alot of you dabble with other stuff too...

Im in need of a little help with my Saab 95 3.0 v6 TID on a 52 plate.

A few days ago I noticed quite a dramatic loss is power it felt like the turbo was not giving any pressure. The next day I got the "Check Engine Light" after a bit of fiddling/checking and the purchase of an OBD2 USB connection I believe I have found the problem to be a faulty MAP sensor.

Im getting the fault code P0107 - Manifold Absolute Pressure / Barometic Pressure Circuit Low and a recent log is showing that is only showing 6kpa near enough all time with the odd spike to around 80ish.

I have tried all the local motor factors and Vauxhall dealer (same engine in the vectra) but only Saab dealers are able to source one at nearly £150 quid.

What I would like from your kind people is do you think that it is the MAP sensor at fault and does anyone have any alternative sources to getting hold of a new one?

GSF

http://www.gsfcarparts.com/

Your diagnosis is plausable. The SAAB uses the MAP along with the MAF to determine how much air the engine is consuming. Without the MAP it cannot and will not fuel correctly. BAsicaly the SAAB controls the torque of the engine by increasing or decreasing the boost, not necessarally to a pre determined set point, but so that at X RPM and X throttle, the engine consumes X amount of air, thus producing X Torque

Map sensors pretty much never fail, inspect the wiring loom carefully for chaffing. Failing that measure the actual voltage output at the sensor and compare it to the obd read out real time,use a mightyvac to try from vacuum all the way to 1.5bar an confirm the readings,if identical and varying,you have a mechanical problem in the vacuum feed, blocked air filter,egr,leak etc. If the sensor swings bit obd stays solid,wiring fault. And if neither vary, sensors dead. :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Assuming the wiring isn't shorted to ground or +5v :) and assuming the sensor is reviving the correct power and ground feed!

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Thanks both,

after speaking with a saab specialist apparently these sensors are a common failure and my symptoms match those of a failed sensor.

Nick came over with his meter earlier (mine isnt at home) and we did a bit more digging, sensor is getting a perfect 5v feed and a good earth, the output wire is showing nothing when disconnected from the sensor (which i would expect) but then shows -0.05ish on plugged in and running... OBDII still reports 6kpa at any rpm.

No issue with vac feed as it bolts direct into the manifold

Im pretty confident now that the sensor is dead, pity they are £150 for a replacment... bugger...

Ah, last ditch, take it off and get in about it with carb cleaner , as it's already dead, I'd there mounted to the manifold they can get full o ahite :) also if there's a par number on it have a google see if you can get one cheaper :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

And I assume by signal disconnected u still had power feeds/earth connected?

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.