Getting the efan working has been on the back burner, and still not solved.
Hopefully someone has a comprehensive ms43 pinout then could link to.

Sent from my XT1563 using E46Fanatics mobile app

 

When you say efan are you referring to the DME built in fan for ECU cooling. Different apps use different names. IN INPA the aux fan is referred to as e-luefter

What tool did you scan with that said e-fan

Was you code any of these:

If you are using P.A. Soft BMW scanner 1.4.x the error will be recorded as thus:
# ERRORS DETAILS - DTC(hex)/PARAM(hex)
---------------------------------------------------------------------------------------------------------------------------
DME -> 7D/A1 - Electric fan, fault

If you are using INPA the error will report as thus:
125 E-Luefter - Activation Electric Fan,

Other error codes that may appear when diagnosing a faulty electric fan unit
279D Control engine fan
279F Output fan A
27A0 Control E-box fan (This is not the cooling fan but the engine ECU fan on late model e46’s)
(108) 6C Activation, electrical fan

 

Boom! First search result returned for "ms43 pinout".
http://forum.e46fanatics.com/showthread.php?t=870338

Also, in case you didn't notice the red link in BMW-North's sig, his wonderful efan guide!
https://drive.google.com/file/d/0B59e0P388oUjMDNkWDk5SkwxVlE/view

 

Boom! First search result returned for "ms43 pinout".~~~~

Thanks Bali... wish it was that easy. I've been through all the standard troubleshooting procedures, including both links.

The pinout thread does not make reference to the aux/e-fan, nor does the guide.
I believe the pinout list is incomplete and has some other inaccuracies and would hesitate to use it as reference.

If I get some free time I may bite the bullet and start probing. I'll report findings if I do.

When you say efan are you referring to the DME built in fan for ECU cooling. Different apps use different names. IN INPA the aux fan is referred to as e-luefter

Using INPA, 125 E-Luefter
Only error on the car. Will not activate for engine startup test-spin, during operation, or with inpa command.

 

You are my favorite human.

My thought is a break in continuity or damage to the wire. Something resulting in high enough imperdance to cause the signal not to trip the final stage.

I do have access to a scope. If the wire is clear, I fear the only thing left is the DME itself.

This has been one of the most irritating troubleshoots I've run into...

I'll test out the signal wire, connectors and report back.

 

Not sure if you have access to any spare parts but here's what I would do. It's exactly what I did in the linked video in my Fan Guide.

Daughters fan wasn't responding to INPA test. Her's is an automatic so fan is buried behind fron bumper. I Borrowed another fan (doesn't matter if it's for an auto or manual) and sat it on top of the engine - connected harness which is reachable without removing anything and ran test - fan responded as it should Confirmed that it was the Bosch Fan module on shroud and not the PWM signal wire at fault.

Now you may have done this and that's why you're looking for the pin out at DME for the PWM signal but I've never known DME to fail on that terminal. Last year I thought it had when I was diagnosing an e90 that DME wouldn;t drive the fan with, turned out to be something else and not the PWM signal.

BTW you can use an e90 fan to test also as it has the same connector harness and it's final output uses the exact same logic.

Edit: One last item of note, I've given up trying to get a measurable voltage signal on the PWM signal during INPA test to see if it is the wire or the final output module (Bosch box) - I just use a known good Bosch Box to see now. I think you need something a little more sophisticated than a voltmeter to see the PWM signal fluctuate.

 

Thanks for the input, and thanks for the great guide!
Indeed, I have tried the whole testing multiple fans on multiple cars.
All the fans I had purchased ran on other cars, but not mine... uhg..

Who knows, I may be a 1 in a million. I do have an extra MS43 I can throw in to see if the DME is at fault...

 

Just noticed you're only about 40 miles north of me. My oldest is moving there in 2 weeks. BTW - I've had 2 DOA aftermarket Chinese fans - makes the job very difficult. Now I use kludged Bosch components from Ford and Mazda.

As I understand it the 125 e-luefter error is derived when the DME sends a startup PWM signal to the F/O (Bosch box) the FO sends a specified voltage to the fan motor, it measures the voltage generated by the fan spinning and refers that to a threshold of expected values. If the value returned does not fall within that range the error is sent to DME. That would infer if your fan spun at startup then F/O was receiving the DME initated PWM signal but determining an issue from the return value expected.

Does your Fan spin at all at startup? Can you force the fan on by creating a failsafe scenario? (CTS unplugged and AC=ON)

 

Only way the fan spins is to hotwire the motor

I think Ive tried to force an on condition in the past with no luck (also no response from inpa).
I'll give it another try today.

Drop me a line if you come up north, and far enough west...

Sent from my XT1563 using E46Fanatics mobile app

 

The crucial thing to diagnose this is knowing that the test fan works.

If you did the INPA test the way I did in the video in the guide (on known good test fan) and there was no response you are left with two possibilities:

1. damaged PWM signal wire

- a simple continuity test of the line should determine if this is the case.

If the PWM signal wire is fine then the issue is with DME. - if this is the case you will be the first one I've come across where the DME failed on the aux fan signal.

2. Bad DME

What did the continuity test reveal?

There is an old thread on here from about 6 years ago where we were discussing measuring the PWM signal at the pigtail connector and one of the members did it using an oscilloscope (in case you have access to one)

 

Wahoo! I have a working fan!
As suspected it was a continuity issue.. but not nearly as bad as it chould have been.
Peeled back the electrical tape wrapped around the fan harness and sae this little bugger. Snipped out the bad part, soldered in some wire and heat shrinked.
Fan goes spinny spinny.

Sent from my XT1563 using E46Fanatics mobile app

 

That's odd- Jenn's 2004 broke that same wire. Except that it physically separated about 1/2"
I was sure someone had cut a chunk out of it- but we looked at the ends under a microscope,
and damned if they didn't match.

I wonder if BMW short- wired some of the harnesses... I'd written it off as 'weird **** just happens'.

t