MAF voltages and pinout.. help!

[fujioko]

Hi ‘ya folks,

I’m trying to trouble shoot a possible faulty MAF on a 1994 325 with Vanos.

Anyway the stomp test indicates the MAF is faulty, however I wanted to double check the voltages before I condemn the MAF.

The MAF on this car has a circular connector with four pins. Would anybody know the pin out on this type of MAF.

Also it would be helpful to know the expected voltages.

Thanks!

[Jr ///M5]

Unplug the MAF, start the car, if it idles fine....it's the MAF, order a new one....or you could spend time messing around spraying that MAF cleaner in it, finding the pin outs, shorting out your ECU and such and then.....order a new MAF.

Call Patrick at BMA tomorrow, I'm sure he could have one at the lowest possible price to you in just a day or so. Get ready, they are rather pricy. Mine went out just before our annual trip to the E34 Summer Meet in Chicago, Patrick had one on my doorstep the day before I left. 10 minutes to plug it in and everything was back to normal.

Good Luck,
JR

JR

[fujioko]

Hi ‘ya JR..

Thanks for the response .. There may be an electrical problem and I want to double check the voltages before I replace the MAF.

Ok, so this car is a E36 3 series.. I have found in the past that the smarter folks are always in the 5 series section. Forgive me for posting in the 5 series section.

The car in question is a 94 325 with a M50TU (single Vanos)

The MAF on this car reads the air flow and I believe the incoming air temp.

I found the ground pin easily enough, however I’m stumped with the other voltages. I’m getting 14.00 volts , 12.00 volts and 8 volts on the other pins. I assumed this sensor would have a 5 volt reference. Hmm…

Can anyone help identify the pinout on this MAF sensor. I think the ECU may be damaged and outputting 14.00 volts instead of 5 volts.

The MAF on this car has a circular connector with four pins. Can anyone help??

thanks

[bad_manners_god]

On the DME:

Pin 14: Airflow Sensor Input
Pin 41: Air Mass Sensor Input
Pin 59: 5 volt Output reference for TPS and Airflow Sensor
Pin 77: Air Intake Temperature Sensor Input

Resiatance:

Mass Air Sensor:

-Between Terminals 5 & 6 (3-4Ohms)
-Between Terminals 1 & 5 (16,300Ohms)