Dealer & Reset Tool Codes

[cai]

My previous diagnosis with the resetting tool was incomplete. I have done a new diagnosis and have the following information:

Table 0F in the tool manual:

Hexadecimal tool code BMW dealer code
A4 - ambient pressure sensor 164
1A - mix control, off idle cylinders # 1-4 26
1B - mix control, off idle cylinders # 5-8 27

The dealer calls the codes 1A and 1B:
code #26 - multiplicative mixture adaptation bank 1, control limit reached
code #27 - multiplicative mixture adaptation bank 2, control limit reached
code #164 - atmosphere pressure sensor

This could be a sticky PCV valve. Does anyone know if these cars have a PCV valve that could be clogging or sticking and where it is?

Thank you.

 

[navybob]

same codes

I get the same two codes on my 2000 740il (1a and 1b). If you find out what is causing them I would love to know. I was wondering if maybe the plugs were bad. Good luck!

 

[cai]

navybob:

I have good news and bad news . The good news is that the problem has been tentatively identified. It seems to be the "pcv" valve that is in the back of the intake manifold. I have not done this test, but, with the car running and warmed up, pull the oil cap open, if you hear a swish - as a vacuum- then it is this valve.

Now for the bad news, it costs about $600 to fix at the dealer. Outside people may do it for less. Let me know if you are in the DC area and maybe we can get a discount at either one of two BMW specialty mechanic shops in the Virginia area.

 

[cai]

Attn: NavyBob

Great News! Finally took my car yesterday to the semi-dealer where I bought it and today they diagnosed the car as only having a loose connection hose, or something to that effect, underneath. Apparentlly they hooked it up and everything is OK.

Notwhithstanding the codes that were present, these people concluded that there was nothing wrong with the car. They hooked-up what they call the smoke machine, to the air intake and that is how they found out where the leak was. Just think that another semi-dealer BMW mechanic wanted $750.00 to replace the rear plate in the intake manifold, I think that under $100.00 for diagnosis and repair is not that bad.

I will learn more when I pick-up the car tonight and will tell you exactly what it was that was loose.

 

[cai]

Disappointment

Brought the car back and within 23 miles the warning was back up. I will have to bring the car back.

 

[cai]

Finally Fixed & Warning

Picked up the car last Friday and after two weeks of intensive diagnosis, it seems as if the problem has finally been fixed. I drove the car for over 200 miles this weekend and the "check engine soon" light did not come on.

According to the mechanics, what was bad was the mass air flow sensor, the one that sits just a bit downstream of the air filter. They replaced it twice, because the first replacement did not work.

WARNING! The mechanic said that the use of K&N air filters voids warranties on these sensors. He said the the oil used in the filters can travel and destroy the sensor elements.