hey yall...i've got a 96 850 turbo with a check eng light on...I have a code saying bad idle air valve...replaced with a spare same code...checked connector with key on, has 12v in center but nothing at other two pins. Was told that one of the other pins should be reading about 6-8 volts. The advice went on to say that if there was no power at 2 of three pins that I should replace cmp sensor...is that the cam position sensor?
The car runs fine...cel driving me batty...only getting about 19 mpg mix town and hwy.
Any help would be appreciated. thx, Peter

 

Are the hoses good? Not sure what the CMP is.

 

hoses are fine. cmp=camshaft position sensor. The ask the mechanic thingy gave a tutorial on diagnosing a idle air gizmo...at the end it mentioned if all this fails replace cmp sensor...how are they related?

 

Sounds like a generic "ask the mechanic" thingy (as you put it) Likely completely useless for Volvos. Find a wiring diagram, and check for continuity between the IAC valve wires and the ECM. If that doesn't solve it, Volvo has wonderful flow charts for diagnosing causes of trouble codes, and these can be found on ALLDATA. I recommend going to Alldatadiy.com and purchasing a subscription for your car. The biggest point to remember: codes do NOT tell you what is wrong with the car. They give you an idea as to where you might look for the problem,but they don't tell you what the problem is.

 

actually it was good advise and specific to the 850 with pics and all.
I am going to look up wiring and hopefully figure it out. thanks for the input and have a good one!