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DISCUSSION => Engine management => Topic started by: m42mb on June 18, 2012, 02:31:08 PM

Title: code 1215 MAFS
Post by: m42mb on June 18, 2012, 02:31:08 PM

I have been having power hesitation problems on my 1994 318is.  i have cleaned the mass airflow sensor, the idle control valve, and have replaced the valve cover and spark plugs.  The car is running better now, however, there is a breif loss of power when the engine temp is 1/2 way between cold and operating temp and this causes the the 1215 mass air flow sensor fault code.  I replaced the O2 sensor last year.  When the engine is cold or at operating temp, it seems to be running normally, although I can't test drive it completely as I'm concerned it may lose power.

The Bentley service manual suggests testing the mass airflow sensor resistance across pins 1 and 5 (I also tried 2 and 5).  The resistance does not change when I move the vain/door through all its travel with the sensor disconnected.  However, the when I test the voltage difference with the sensor connected and the ignition on the voltage changes when I move the door.  This means to me that a signal is being generated when airflow is changing, although I could be wrong.

Any comments would be appreciated.  Thanks!

Title: code 1215 MAFS
Post by: DesktopDave on June 19, 2012, 06:58:22 AM

I'm pretty sure the AFM signal is sent from pins 1&2.  On my e30 pins 4&5 are for the intake air temp sensor.

I'll double check & report back.