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Hi all,

I have a fault code and get the reduced power massage.
0x27A2 drosselklappensteller enable-leitung bank2
P157F drosselklappenfreigabeleitung schaltkreis(bank2) leitungsunterbrechung

Anybody knows what this is?

Thanks
Sven
 

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Discussion Starter #2
Okay it seems to be the throttle sensor. Anybody knows where it is , is it near the actuators?

Thanks
Sven
 

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Before you buy a new TA, what it specifically complains about is the enable line into the TA. In German it says it is interrupted. This enable line comes from the DME through the harness. It may just be a harness wire integrity issue when you ruffled it feathers under the hood. The way to check this is by switching the TA in place and see if the problem moves to the other side. If it stays it is the harness if not it is the TA.
 

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I'd use DIS or similar software to clear the code and then go a diagnosis test to check the throttle actuators to confirm.
 

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Thanks guys. rt7085 it was showing this fault before we ventured under the hood. 2Live4 cleared codes and and 27a2 plus new one 27af ?????????
 

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Measure Impedance

Thanks guys. rt7085 it was showing this fault before we ventured under the hood. 2Live4 cleared codes and and 27a2 plus new one 27af ?????????
That is very interesting. Well, it is either the harness and/or the ENABLE line. Somehow the DME runs a diagnostic check on this line, probably an impedance check. Internal to the TA this line leads to a comparator. On the bench I verified that this line does not turn off the TA. I think it just tells the TA not to function/move. The micro processor senses this line and makes a decision. I measured the expected resistance to GND and it is 102kOhms, verified on 2 units that work properly. Measure between pins 1 and 3 on the TA. See attached for TA pin numbering.



Larger than 100 kOhms is a design issue! Any PCB contamination or a compromise of wire insulation will reduce this value considerably and the diagnostics on the DME side probably trip up. Not sure at what exact value. Again, switching the units will reveal if it is the harness or the TA beyond the pin measurement.
 

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That is very interesting. Well, it is either the harness and/or the ENABLE line. Somehow the DME runs a diagnostic check on this line, probably an impedance check. Internal to the TA this line leads to a comparator. On the bench I verified that this line does not turn off the TA. I think it just tells the TA not to function/move. The micro processor senses this line and makes a decision. I measured the expected resistance to GND and it is 102kOhms, verified on 2 units that work properly. Measure between pins 1 and 3 on the TA. See attached for TA pin numbering.



Larger than 100 kOhms is a design issue! Any PCB contamination or a compromise of wire insulation will reduce this value considerably and the diagnostics on the DME side probably trip up. Not sure at what exact value. Again, switching the units will reveal if it is the harness or the TA beyond the pin measurement.
I have always understood that error to mean that the DME has disabled that line moreso than reporting an error on it. I could be wrong, but seems like the DME's in charge of that line and it's only an analog output channel.

dk enable.jpg
 

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Translation

The -exact and correct- german to english translation of this is (because I speak German; this is not Google):

"0x27A2 drosselklappensteller enable-leitung bank2
P157F drosselklappenfreigabeleitung schaltkreis(bank2) leitungsunterbrechung"

"0x27A2 throttle value servo enable signal bank 2
P157F throttle value release signal circuit (bank 2) signal interruption"

.....which is suggestive of a diagnostic failure on that actual line. From experience, I can tell you that all signals in automotive modules, especially under the hood, with exception of power and ground, are typically diagnosable one way or the other.

But I could be wrong. (The usual disclaimer.)
 

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27A1 DME: Throttle-valve actuator, enable line bank 1

Hello guys,

Reviving old thread. I have been getting lately error code "27A1 DME: Throttle-valve actuator, enable line bank 1". Lot's of threads about this "enable line code" and some say it was the throttle sensor and some say it's not. Seems like member rt7085 has done some serious testing about the actuators and very useful information in this thread.

Do you have any information what are the conditions when DME shuts the throttle actuator down, and can anyone verify that is this code for line integrity or some internal fault in the throttle actuator?

Error goes away when i shut off the car and restart. Battery and charging are good. Planning to tear down the plenum at some point and check the actuators and enable line. Have to wait to get new laptop and diagnose car with ISTA because old laptop broke down...

So if anyone of you have encountered this problem and solved it, please chime in. I will report back when if have this problem solved. Thanks!
 

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solved it by replacing both TA's on mine. Are you getting the physical symptoms too? (limp mode on occasion, no DSC etc)
Yes. When error occurs, getting limp mode, DSC etc. warnings right away after i start the car and touch the throttle pedal. Now it's been 3 days without the error. Forgot to mention those symptoms in previous post.

I'm thinking that the bank 1 actuator is failed internally and the "enable line" wire itself is in good shape. But you never know with BMW's.

Planning to change both actuators when i have time and get my new laptop. Also going to measure internal resistance from actuator pins. Yesterday i measured spare ones and those showed 102kOhms like rt7085 wrote some time ago.

Thanks for the input!
 

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Yes. When error occurs, getting limp mode, DSC etc. warnings right away after i start the car and touch the throttle pedal. Now it's been 3 days without the error. Forgot to mention those symptoms in previous post.

I'm thinking that the bank 1 actuator is failed internally and the "enable line" wire itself is in good shape. But you never know with BMW's.

Planning to change both actuators when i have time and get my new laptop. Also going to measure internal resistance from actuator pins. Yesterday i measured spare ones and those showed 102kOhms like rt7085 wrote some time ago.

Thanks for the input!
mine went precisely the same way. Some days; no issues. Other days; I'm pulling my hair out.

Some guys have had success replacing the gears but others don't. I just went with new actuators.

If your idle actuators haven't thrown in the towel yet be prepared, they will too. All the same physical symptoms but you lose hill start assist as well.
 

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mine went precisely the same way. Some days; no issues. Other days; I'm pulling my hair out.

Some guys have had success replacing the gears but others don't. I just went with new actuators.

If your idle actuators haven't thrown in the towel yet be prepared, they will too. All the same physical symptoms but you lose hill start assist as well.
Did you had the "enable line" code when your actuators went? I have refurbished spare actuators by http://www.rebuild.org.uk so i think those will perform great. Maybe it's time to buy the idle actuators just in case:smile
 

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27A1 DME: Throttle-valve actuator, enable line bank 1

A little update to my problem. A week ago i went to the local dealer for software update. I have been planning to do this update for a while. After the update no more codes from throttle actuator. I'm a little sceptical that the update fixed my problem but we'll see... If/when the error pops up again i'm changing the actuators for rebuilded ones.
 

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I have only had the fault code P157F and was hoping for some clarification, sorry if posted twice, phone acting up. Is this specific to the throttle actuator itself only or could it also be the sensor? Wanted to start process today of getting proper parts and tools. Thanks for any insight!
 
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