Author Topic: How many of you have the AFM adapter harness? (Read 6985 times)

Cobra Jet · « **on:** March 06, 2009, 09:51:49 AM »

I've read the Service Bulletin Number 13 03 91 (3290) and in some pics of M42 engine bays on multiple forums, I see that some folks do have the AFM adapter harness, while others do not...

Was this item only replaced if the vehicle was brought into the Dealer under it's original Warranty period - or were these replaced via a mandatory recall letter campaign of the time?

For those that have NO idea what I'm referring to - apparently BMW created a short jumper harness that on one end has the circular connector that plugs directly into the AFM - and on the other end, there is another circular connector that gets plugged into the original AFM engine harness connector.

The reason being based on the Bulletin is: "Due to an occasional impairment of the signal between the air flow meter potentionmeter (AFM) and the DME control unit, the engine idle may dip below specification at times causing a possible rough idle condition."

The adapter harness part # is 13 62 1 734 516. It is installed between the engine wiring harness and the AFM. This adapter harness incorporates an impedance converter which filters and amplifies the signal from the AFM to the DME.

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My 91 318ic does not have this adapter harness.

If your vehicle has had this adapter installed, you would not only visually see it, but the BMW Dealer that installed it would have stuck a circular sticker to your driver's side door jamb and code "58" would have been punched out on this sticker.

So who has the adapter harness?

colin86325 · « **Reply #1 on:** March 06, 2009, 10:19:16 AM »

I have it.

batsbats · « **Reply #2 on:** March 06, 2009, 11:00:41 AM »

Funny you mention this..

Other day I had driven my M42 just fine to 7-11 and back. A few hours later, upon startup, the engine was idling wild. Jumping from 500-2k, surging up and down. Had zero time to mess around, and borrowed a car to get to work.

Check engine popped up, and I pulled the code. Got 1215: AFM..

My dad the next day (while I was at school), fiddled with the AFM, and unplugged and replugged the circular connection to the AFM, and voila!

Selfish · « **Reply #3 on:** March 07, 2009, 11:17:52 PM »

I don�t have it. It�s a 318i. Anyway, what is the correct idle speed? Mine used to idle steadily at aprox. 750-800 rpm

txleadfoot · « **Reply #4 on:** March 08, 2009, 12:48:18 AM »

Does it look like this?

I found this in my spare parts bin. Never been installed on any of my E30 M42s. I did attach this and the engine does start/run. Appears to simply extend the wiring. There are three sets of numbers molded into the rubber boots:

Rectangular Boot: 1 284 463 500 and 1 734 516.3
Circular Boot: 1 710 674 15

Jimmy Lewis · « **Reply #5 on:** March 08, 2009, 10:58:26 PM »

I have the adapter harness and have the sticker on my door jam. Never really new the point of it, because the car runs fine with or without it installed. You learn something new everyday.

1991 E30 M42 · « **Reply #6 on:** March 08, 2009, 11:24:34 PM »

Danny707 · « **Reply #7 on:** March 08, 2009, 11:25:59 PM »

Cobra Jet · « **Reply #8 on:** March 09, 2009, 09:18:18 AM »

Quote from: txleadfoot;67898

Does it look like this?

I found this in my spare parts bin. Never been installed on any of my E30 M42s. I did attach this and the engine does start/run. Appears to simply extend the wiring. There are three sets of numbers molded into the rubber boots:

Rectangular Boot: 1 284 463 500 and 1 734 516.3
Circular Boot: 1 710 674 15

Yep, that is the adapter harness. The part #'s you have referenced are just for those individual pieces that make up the part.

So, you have never used it on any of your M42's? Does any of your M42's have the circular decal on the door jamb? Interested in selling or are you going to hold onto it?

txleadfoot · « **Reply #9 on:** March 09, 2009, 12:41:18 PM »

Are you sure this adapter is M42 specific? When I pull up the P/N on realoem.com, the part is only listed for the Euro 316i/318i M40.

ak96ss · « **Reply #10 on:** March 09, 2009, 01:20:48 PM »

One of the 318is' I parted out had this, mine does not.

Cobra Jet · « **Reply #11 on:** March 09, 2009, 02:10:07 PM »

As for the part # I listed in the original thread, yes, M42 specific. I actually have the BMW Service Bulletin saved as a PDF... I tried to put it into my original thread, by u/ling it, but for some reason, the U/L failed each time I tried to insert the file when making the initial thread... The file size is not all that big either...

I can email it to you if you want - just PM me your email, maybe you can then link it to this thread?

Voluted · « **Reply #12 on:** March 11, 2009, 10:02:37 PM »

I have this. When i saw it i thought it was a useless extension cable. Cool!

bmwman91 · « **Reply #13 on:** March 12, 2009, 01:34:18 AM »

My car HAD one. It got hacked up when I did my MAF conversion as I needed the connectors lol. I am willing to bet that it is nothing more than a capacitor to attenuate the AFM's output at low engine speeds.