[Ethird]

Hi All,

My E70s electric fan appears to be inop, but it's not the fan itself. When I start the car, I don't get the 20-second fan run that I've seen is standard on the car. I recently had the fan out to replace the radiator (leaking) and a few hoses (soon to be leaking). Upon reinstall, I ran the car up to 97C as reported by the Torque app on my phone, and the fan never engaged. I wasn't sure of the operating temps so I didn't want to run the car any warmer than that.

The A/C has been out on the car for about a year now, and I hadn't been able to figure out why. It seems possible that the car won't run the AC because the radiator fan is not operating, which would mean the fan's not run for the past year. I've not once received an overheat warning on the dash.

I bought a new Genuine BMW fan and plugged it in - still no 20-second run up. I replaced the fan relay in the passenger's wheel well, and no fan action on either the old or new fans.

The only way I can get the fan to run is if I start the car, then plug in the fan connector. At that point, the fan will run full speed until I stop the engine - then it will not start again if I restart the vehicle. It will do this if I have the relay in place, or if I remove the relay from the circuit entirely.

I checked the signal wire and saw 100 hz of frequency. Does anyone know what the operating frequency for this wire is? Maybe that's my problem?

Pulled codes (no dash lights on) and got 2EFE - cooling fan, 2E83 coolant pump reduced power, 2E97 alternator, and 2DEB power management failure. This is a very odd set of codes - I can't imagine the water pump is failing if I have a functional fan that's not spinning - seems the car would spin it at full speed as I've seen posted on some comments about failing water pumps on the forums.

Really getting frustrated on this issue. Please help! I did throw my multimeter on the coolant temp sensor, and got no voltage or resistance (car switched off). Not sure if that's a valid test for this car, though - it's so incredibly dissimilar from my E46. Any and all help is appreciated.

 

[Doug Huffman]

In re your 100 Hz signal; BMW likes to use PWM power supplies for variable effective voltage to DC motors and components.

This is Engine Heating/Cooling Systems, All Models, All Productions
https://drive.google.com/open?id=0B1epIteFE7i-RDhHMHBNQlk1Wms

This is Cooling Systems, All Models, All Productions
https://drive.google.com/open?id=0B1epIteFE7i-SWJHVnotdVpHZGc

There are similar documents there on battery basics, power management, voltage management. Your alternator and power management errors make me think of my favorite, your battery. How old is it, how much capacity remains, is it fully charged? With failing electrical power the BMW selectively disables electrically powered systems - as detailed in one of the power management documents.

Best wishes.

 

[acoste]

The only way I can get the fan to run is if I start the car, then plug in the fan connector. At that point, the fan will run full speed until I stop the engine - then it will not start again if I restart the vehicle. It will do this if I have the relay in place, or if I remove the relay from the circuit entirely.

That's super unexpected. If the relay doesn't make a difference then I suspect there is no power going to the relay. Check the 60A fuse F45 in the junction box (or F171 for cars with trailer module)
Or the relay doesn't receive the enable signal. The enable signal goes through a 5A fuse F127 in the rear power distribution box. Check if that guy has 12V on it.

The temp sensor at the radiator outlet is a resistive element so you should be able to measure some impedance.

 

[Ethird]

That's super unexpected. If the relay doesn't make a difference then I suspect there is no power going to the relay. Check the 60A fuse F45 in the junction box (or F171 for cars with trailer module)
Or the relay doesn't receive the enable signal. The enable signal goes through a 5A fuse F127 in the rear power distribution box. Check if that guy has 12V on it.

The temp sensor at the radiator outlet is a resistive element so you should be able to measure some impedance.

The thing is - it would only work in that mode regardless of the presence of the relay in the circuit. When I bypassed the relay, I still had to plug the connector in while the engine was running in order to get the fan to run, and it ran at full speed until the ignition was switched off, just like with the new relay installed.

Thanks for your comment - this may sound ridiculous, but I can't find fuse 45. It's listed on my car's fuse list, but it's not shown anywhere in the diagram, which is the same printed document that contains the list that says that fuse 45 is the one to check. The X5 is a 2007, and I've noted later cars changed the fuse numbering on their sheets. I have 45-48 listed on my sheet but nowhere to be found in the location diagram.

I will definitely check voltage at fuse 127 and see what that tells me.

 

[acoste]

Pulled codes (no dash lights on) and got 2EFE - cooling fan, 2E83 coolant pump reduced power, 2E97 alternator, and 2DEB power management failure.

power management failure is the suspicious part for me.
In my previous message I mentioned the F127 that receives power from the power management. That signal is connected to the 30G wire.

Lot of high consumers are attached to the 30G. For example air conditioning, steering column parts, aux fan, glove compartment lock, iDrive controller.

Does your steering column adjustment motor working?

 

[acoste]

Thanks for your comment - this may sound ridiculous, but I can't find fuse 45. It's listed on my car's fuse list, but it's not shown anywhere in the diagram, which is the same printed document that contains the list that says that fuse 45 is the one to check. The X5 is a 2007, and I've noted later cars changed the fuse numbering on their sheets. I have 45-48 listed on my sheet but nowhere to be found in the location diagram.

I will definitely check voltage at fuse 127 and see what that tells me.

The WDS (BMW Wiring Diagram System) contains some errors unfortunately. So it must be another fuse. Worst case you could measure at the relay if it has power. But that's hard to access.

 

[Ethird]

In re your 100 Hz signal; BMW likes to use PWM power supplies for variable effective voltage to DC motors and components.

This is Engine Heating/Cooling Systems, All Models, All Productions
https://drive.google.com/open?id=0B1epIteFE7i-RDhHMHBNQlk1Wms

This is Cooling Systems, All Models, All Productions
https://drive.google.com/open?id=0B1epIteFE7i-SWJHVnotdVpHZGc

There are similar documents there on battery basics, power management, voltage management. Your alternator and power management errors make me think of my favorite, your battery. How old is it, how much capacity remains, is it fully charged? With failing electrical power the BMW selectively disables electrically powered systems - as detailed in one of the power management documents.

Best wishes.

Thank you for your help, Doug - based on the Carfax, the battery was replaced in May 2013 at the dealer. We purchased the car in December of that year, so it was shortly before we bought it. We've put about 30k miles on it since that purported battery replacement, so it shouldn't be anywhere near where I'd consider it dead, though I have seen from the forums that these cars tend to run through batteries fairly quickly. I was considering that possibility myself - maybe I'm chasing my tail here and the car has stopped running the fan test on startup to save juice while it tries to charge the battery.

I'm getting high 13.X voltage with the engine running at idle, and haven't thought to check static battery voltage. That's an interesting speculation.

 

[Doug Huffman]

I don't know how you are checking voltages. BMW cautions NOT to disconnect the battery for troubleshooting for modules with volatile memory.

A three year old battery is just middle aged. Buy a battery CHARGER that can detect an AGM battery and charge your battery using the underhood access points until the charger indicates FULL or FAIL. It may take 24 hours the first time. Your BMW will NEVER EVER fully charge its battery.

Go to my profile page, STATISTICS | ALL THREADS for my battery stuff gleaned from BMW technical documents, BatteryUniversity.com and BatteryFAQ.org. I have started very few threads other than those.

 

[Ethird]

I don't know how you are checking voltages. BMW cautions NOT to disconnect the battery for troubleshooting for modules with volatile memory.

A three year old battery is just middle aged. Buy a battery CHARGER that can detect an AGM battery and charge your battery using the underhood access points until the charger indicates FULL or FAIL. It may take 24 hours the first time. Your BMW will NEVER EVER fully charge its battery.

Go to my profile page, STATISTICS | ALL THREADS for my battery stuff gleaned from BMW technical documents, BatteryUniversity.com and BatteryFAQ.org. I have started very few threads other than those.

I'll check out your links now. Just took a reading from the underhood points with a VOM - getting 12.17V static, so it's certainly low at the moment.

 

[Doug Huffman]

Sorry, that is not 'static'. The battery is always under load.

BMW nominal closed-circuit (BMW for OFF) drain/load is 20 mA and higher in some models. > 80 mA closed-circuit will cause an Increased Battery Discharge warning yellow.

 

[acoste]

I have to leave now but check out this document regarding the 30G signal.

http://www.bmwmotorsports.org/pdf/e70/03c_E70 Energy Management.pdf

 

[Doug Huffman]

I have to leave now but check out this document regarding the 30G signal.

http://www.bmwmotorsports.org/pdf/e70/03c_E70 Energy Management.pdf

30g occurs 59 occasions in that document. I recommend that you read it in its entirety.

 

[Ethird]

Thanks guys - that was a good read. Glad to have a better understanding of power management and cooling profiles on the car. I picked up a new battery charger with AGM compatibility and spent yesterday charging. The charger indicated the battery was at 44% capacity when I began, so it needed a charge regardless of relationship to my current issue. Charged up well and gave me 12.8V on the VOM after sitting overnight with the charger removed.

Sadly, still no operating puller fan. I fired up the car and ran it to an indicated 102C (based on my bluetooth OBD2 dongle and Torque app, so that temp's based on water temp as reported by the ECU) before it plateaued - couldn't get it any warmer than that while idling. If the N52 follows the engine cooling profile of the N54 in the document Doug shared, 102 is below, though perhaps within the margin of error for both "normal" and "eco" operating temps, settings which I would assume the engine would adopt when sitting and idling. Perhaps a soft-failed (open) thermostat could be my issue and the car is preventing the fan from operating in an effort to get the engine up to operating temp? I'd imagine it'd run cooler at road speed with air movement past the rad, but I suppose to test that theory I'd just have to drive it and watch the temps closely. That might explain why I've apparently been operating without a cooling fan but have never hit the 120C threshold for an overheat warning.

Just spitballing - I wish I had a better idea of the operating parameters for the fan, as that might give me more clues as to why it's refusing to operate. The strangest thing to me is lack of the "test activation" upon engine start that seems to be normal for the car.

 

[acoste]

I haven't seen in your thread if you have checked the power and the ground at the fan connector.

You mentioned there is a 100 Hz signal there so the DME wants the fan to run. See the schematic attached. Check if the power (12V) is there on pin 2 and if the ground is there on pin 1 (measure the impedance bw this and chassis)

Also you mentioned the temp sensor reads infinite impedance, but as you can see below it's a resistor so should have a value. Can the Torque app show the temperature at the radiator outlet? I'm wondering, if that sensor is broken, the "sensed" temperature is at minimum.

 

[Ethird]

I haven't seen in your thread if you have checked the power and the ground at the fan connector.

You mentioned there is a 100 Hz signal there so the DME wants the fan to run. See the schematic attached. Check if the power (12V) is there on pin 2 and if the ground is there on pin 1 (measure the impedance bw this and chassis)

Also you mentioned the temp sensor reads infinite impedance, but as you can see below it's a resistor so should have a value. Can the Torque app show the temperature at the radiator outlet? I'm wondering, if that sensor is broken, the "sensed" temperature is at minimum.

I do have 12V at the connector but haven't checked impedance between the pin and the chassis on the ground, so I'll have to check that - thank you for that tip.

The water temp sensor I checked was the one in the head, next to the oil filter housing (10):

I re-checked that sensor and apparently biffed it, because i'm reading something in the neighborhood of .5 kohms now (just ran the coolant up an hour or two ago, so it's still got some heat in the system).

I'm not familiar with a sensor at the radiator outlet and can't seem to find it looking at any of the diagrams - pleading ignorance on that one. I do have an N52K engine - would I still have this sensor?

 

[acoste]

I'm not familiar with a sensor at the radiator outlet and can't seem to find it looking at any of the diagrams - pleading ignorance on that one. I do have an N52K engine - would I still have this sensor?

Not every model has that radiator outlet sensor. Realoem doesn't show any for your car, however WDS does. Your E46 has it and the fan speed depends on that sensor.

For models with radiator outlet temp sensor the fan speed is determined by this temperature. For your model it must be the combination of engine temperature / thermostat status / water pump speed.

Edit: additional to the above mentioned fan speed of course depends on the AC too.

 

[Ethird]

Not every model has that radiator outlet sensor. Realoem doesn't show any for your car, however WDS does. Your E46 has it and the fan speed depends on that sensor.

For models with radiator outlet temp sensor the fan speed is determined by this temperature. For your model it must be the combination of engine temperature / thermostat status / water pump speed.

Edit: additional to the above mentioned fan speed of course depends on the AC too.

Yeah, that outlet sensor on the E46 makes its presence known - car loves to blow out those little green o-rings every 60k or so.

Ground is good from the connector to the body. I was really hoping I had just overlooked that and it was going to be something as stupid as a poorly installed ground strap over to the engine, but it's not meant to be.

 

[acoste]

Side note. I was reading about the M54 engine and run into the electric fan.

The fan is activated based on the:
- coolant outlet temperature
- calculated catalyst temperature
- vehicle speed
- battery voltage
- air conditioning pressure

It is controlled by a pulse modulated signal. So the frequency of the control signal is constant but the pulse width changes.

 

[Ethird]

This is hilarious

On my daily grind today, I took a close look at the body connector that energizes the fan and said to myself, "hey, that signal wire slot looks like it's spread pretty wide."

After all that, it was the dang connector. I just squished the pins closer together with a jeweler's screwdriver, and bam, fan energized with the ignition.

Thanks for all of your troubleshooting help, acoste and Doug. Turns out the mechanic was the only thing that needed troubleshooting.

 

[acoste]

good! :thumbup: