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  #1  
Old 04-15-2019, 02:15 PM
stiiaN stiiaN is offline
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E92 325I Electric fan PWM / Engine heat

Hello, I'm wondering if this looks right?

E92 325 with N53 engine. 3.0liters. 2008.

Should I worry more about oil temp or motor temp? I've seen my oil temp as high as 113C.
And my fan PWM just stays the same all the way, I wonder if my fan is okay?? Or some temperature sensor somewhere.

I've heard sometimes my fan is running at full speed at times. So I guess the fan itself is okay? - But to me, it looks like it should have changed its speed when I drove. When I look at the temps i see....

I've attached a driving log from Carly with Oil temp, water pump speed, Engine speed, Electric fan - PWM, Vehicle speed and Motor temp.

Note, I've just replaced my water pump.

Thanks in advance to any answers.
Regards Stian T

Last edited by stiiaN; 04-15-2019 at 02:16 PM.
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  #2  
Old 04-29-2019, 04:01 PM
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BMW-North BMW-North is offline
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Couple of points. You probably want to adjust your PIDs to provide values that are relevant and true. I assume being in EU you are using a comma to denote a decimal place, but you still don't need values like RPM extended to 6 decimal places.

In regard to the PWM% value for the aux electric fan - this value will remain constant almost all the time at a value below 20% - the PWM fan interpreter does not operate the e-fan at values below and above a threshold (i.e. below 20% and above 95%). The values you are seeing via Carly despite their label however is not the percentage value. It is the value on the PWM signal scale where the scale is Zero =0% but 40 may = 95%. (see attached image of the PWM reported values for the MS 4x DME.) The e9x has a similar structure. The 16.406 PWM value you logged will be a 20% startup test value.

I pulled your original log into my spreadsheet app for analysis (attached as a PDF) and I can see that your fan received a PWM startup fan signal in row #1 - this is a test by DME - it sends a brief value to the fan @ a 20% ratio to activate the fan. - At this point the e-fan turns into a generator and the DME measures the resulting generated voltage (from the spinning fan) to determine the fan RPM - it uses the reported value to decide whether the fan is operating correctly or not. If the reported value is within the acceptable thresholds - No error. If the fan RPM/Voltage is outside this threshold range - an error is reported in DME (e-Fan / e-lufter error).

The e-fan will not kick on until certain concurrent conditions exist. These are a combination of various inputs (i.e. coolant , oil & ambient temp sensor) data fed into DME combined with the other data input (IHKA (AC) status) and the vehicle speed - these input values enter a logic formula and the fan speed is determined (final output). If the conditions warrant DME will send a signal above the 20% value to activate the fan. The PWM signal value will change (decrease or increase) the fan speed as neccessary, based upon the dynamic inputs and final output calculation - the main objective - to maintain the engine at a temperature range for the current driving mode determined by DME - based upon another full set of variable inputs.

You should see a gradual increase in the PWM signal as the conditions warrant - this is typically representative of increases in the coolant and oil sensor temps - especially at idle when there is no moving air from vehicle speed. I've attached a log of an earlier 3 series that does not have an electric water pump (- which in the e9x is similarly PMW signal activated via DME logic). In this log (e46) the key sensor value is the Coolant Outlet temperature (or CTS) which when rising above 85C causes DME to activate the e-fan. The e-fan does not turn off again until the same sensor drops below 80C (this is a built-in hysteresis function). You will see the PWM signal increase to rapidly cool the engine and coolant temperatures. Note the increase and decrease of the e-fan PWM signal in steps.

I'd love to spend more time here providing further info but my grand kids are calling.

Three Tips:

1. Anyway, I've always recommended folk perform an e-fan test using ISTA or INPA to ensure that the e-fan will respond to various signals - Don't think Carly offer that. I've noted speeds often drop off in ranges - even though the e-fan may pass the startup test. The earlier Bosch, Siemens and even the current Gates and Johnson Controls fans (all used by BMW) all work off almost the exact same logic & design. The biggest cause of e-fan failure is moisture penetration into electronic components of the PWM interpreter.

2. Check DME for e-fan errors

3. Log the e-fan PWM signal after engine is fully warmed, perhaps after highway driving and car has come to idle (say traffic light) - if the engine is hot enough and the conditions warrant - the signal should increase - you can manipulate this by turning on AC - the signal should almost immediately increase. (again though if DME permits the AC=ON based on other inputs such as ambient air temp). ** - another reason why one should not drive a newer bimmer with a bad outside air temp sensor - it's used in so many DME decisions.
Attached Thumbnails
Click image for larger version

Name:	DME_MS4x_e_Fan_PWM_signals.png
Views:	20
Size:	30.2 KB
ID:	849971  
Attached Files
File Type: pdf stiiaN-EngineReport_CarlyForBMW.pdf (87.3 KB, 9 views)
File Type: pdf e46_08012019_v3_PID_ log.pdf (1.16 MB, 9 views)

Last edited by BMW-North; 04-29-2019 at 05:23 PM.
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  #3  
Old 05-06-2019, 02:46 AM
stiiaN stiiaN is offline
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Quote:
Originally Posted by BMW-North View Post
Couple of points. You probably want to adjust your PIDs to provide values that are relevant and true. I assume being in EU you are using a comma to denote a decimal place, but you still don't need values like RPM extended to 6 decimal places.

In regard to the PWM% value for the aux electric fan - this value will remain constant almost all the time at a value below 20% - the PWM fan interpreter does not operate the e-fan at values below and above a threshold (i.e. below 20% and above 95%). The values you are seeing via Carly despite their label however is not the percentage value. It is the value on the PWM signal scale where the scale is Zero =0% but 40 may = 95%. (see attached image of the PWM reported values for the MS 4x DME.) The e9x has a similar structure. The 16.406 PWM value you logged will be a 20% startup test value.

I pulled your original log into my spreadsheet app for analysis (attached as a PDF) and I can see that your fan received a PWM startup fan signal in row #1 - this is a test by DME - it sends a brief value to the fan @ a 20% ratio to activate the fan. - At this point the e-fan turns into a generator and the DME measures the resulting generated voltage (from the spinning fan) to determine the fan RPM - it uses the reported value to decide whether the fan is operating correctly or not. If the reported value is within the acceptable thresholds - No error. If the fan RPM/Voltage is outside this threshold range - an error is reported in DME (e-Fan / e-lufter error).

The e-fan will not kick on until certain concurrent conditions exist. These are a combination of various inputs (i.e. coolant , oil & ambient temp sensor) data fed into DME combined with the other data input (IHKA (AC) status) and the vehicle speed - these input values enter a logic formula and the fan speed is determined (final output). If the conditions warrant DME will send a signal above the 20% value to activate the fan. The PWM signal value will change (decrease or increase) the fan speed as neccessary, based upon the dynamic inputs and final output calculation - the main objective - to maintain the engine at a temperature range for the current driving mode determined by DME - based upon another full set of variable inputs.

You should see a gradual increase in the PWM signal as the conditions warrant - this is typically representative of increases in the coolant and oil sensor temps - especially at idle when there is no moving air from vehicle speed. I've attached a log of an earlier 3 series that does not have an electric water pump (- which in the e9x is similarly PMW signal activated via DME logic). In this log (e46) the key sensor value is the Coolant Outlet temperature (or CTS) which when rising above 85C causes DME to activate the e-fan. The e-fan does not turn off again until the same sensor drops below 80C (this is a built-in hysteresis function). You will see the PWM signal increase to rapidly cool the engine and coolant temperatures. Note the increase and decrease of the e-fan PWM signal in steps.

I'd love to spend more time here providing further info but my grand kids are calling.

Three Tips:

1. Anyway, I've always recommended folk perform an e-fan test using ISTA or INPA to ensure that the e-fan will respond to various signals - Don't think Carly offer that. I've noted speeds often drop off in ranges - even though the e-fan may pass the startup test. The earlier Bosch, Siemens and even the current Gates and Johnson Controls fans (all used by BMW) all work off almost the exact same logic & design. The biggest cause of e-fan failure is moisture penetration into electronic components of the PWM interpreter.

2. Check DME for e-fan errors

3. Log the e-fan PWM signal after engine is fully warmed, perhaps after highway driving and car has come to idle (say traffic light) - if the engine is hot enough and the conditions warrant - the signal should increase - you can manipulate this by turning on AC - the signal should almost immediately increase. (again though if DME permits the AC=ON based on other inputs such as ambient air temp). ** - another reason why one should not drive a newer bimmer with a bad outside air temp sensor - it's used in so many DME decisions.
Thanks for your reply. I'll try your tips.
Sorry for my late answer. But I was driving in some traffic the other day. I noticed the temps to rise again to almos 120 oil temp.... But just when the oil temp hit around 114 ish. I saw the fan pwm rise to 50% ish and the temp came down again. And it keept on going like that up and down while i was stuck in abit of traffic. But isn't that a bit late for it to hit that? Shouldn't it have been at that speed much earlier? So compared to yourspreadshet it is 20% ish in speed..?
I have a computer with instaled inpa and ista, so ill try that as well. And run som fan tests. Ive checked for fault log after every drive Ive done so far. And non is relevant to the fan.

Anyway i will try inpa/ista and Report back if I figure something out.

Thanks!

Last edited by stiiaN; 05-06-2019 at 03:13 AM.
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  #4  
Old 05-06-2019, 09:10 AM
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BMW-North BMW-North is offline
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Seeing you have Carly next time you are driving monitor the following:
1. Oil temp,
2. Coolant outlet temperature,
3. Engine Coolant temperature,
4. e-Fan PWM,
5. Waterpump Actual RPM
6. Waterpump Requested RPM

The drive test cycle should include a warm up period that gets the car up to normal temperature, a brief 10-15 minute highway (speeds constant and > 80 km/h) then a slow down to idle or stop 'n go traffic for 5 minutes.

Post the log - really only need the last 10 minutes.
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