e36M42 engine in e30: DME error code 85

[selespeed]

I have this constant error in my DME 1.7.2 (stock) always.

i have this error code 85 in my DME constantly. I don't know what the mechanic did to my a/c. i would like to have this error removed entirely. but the mechanic is not willing to tell me how to do it nor is he willing to do this I did this in another city that is far away. I believe he did some short cut resulting in this...

=========================
Details of error on diagnostics says that:
- no increase in idle speed even thought air conditioning compressor is running
- open circuit at pin 86 od DME control unit
- short circuit to battery positive at pin 85 of the DNME control unit

Fault Information
Air Conditioning = ON
If not ok: check wire to DME control unit pin 85
Set temperature control wheels to WARM and switch off defroster, recirculated air or air conditioning switch.
Compressor Normal value = OFF

Air Conditioning Compressor = ON
If not ok: check wire to DME control unit pin 86
===================================

Anyone of you here using e36M42 engine in e30? how did you solve this problem? What's wrong and how to restore it? Did he do something to my A/C relay?

The engine stalls occasionally when idling. not sure if there is something to do with this

Thank you.

[Brianmoooore]

Do you have aircon. fitted to your car?

[selespeed]

Do you have aircon. fitted to your car?

yes of course i have. in order not to make the engine die during idling, he did something. but this turned out to be error code 85

[Brianmoooore]

Why " of course I have"? Air con. is a rare option on a UK car - at a guess, less than 5% have it.
Pin 85 of the ECU should be connected to 12 volts + by the air con. switch when you turn the air con. on., which increase the idle RPM. This should be a black/purple wire at the switch, changing to purple/grey at the ECU.
Pin 86 on the ECU (black/grey, changing to black/red) is the air con. actually running, rather than the switch just being on, signal to the ECU. I suggest you check these two 12 volt + signals are present at the ECU when they should be.

[selespeed]

Why " of course I have"? Air con. is a rare option on a UK car - at a guess, less than 5% have it.
Pin 85 of the ECU should be connected to 12 volts + by the air con. switch when you turn the air con. on., which increase the idle RPM. This should be a black/purple wire at the switch, changing to purple/grey at the ECU.
Pin 86 on the ECU (black/grey, changing to black/red) is the air con. actually running, rather than the switch just being on, signal to the ECU. I suggest you check these two 12 volt + signals are present at the ECU when they should be.

oh here a/c is a must due to the hot climate. i am in singapore.

but where do you think the mechanic has done this? when the a/c switch is pressed (turned on), a/c is running but it has lots of errors. he probably changed only one part.

how should it be done in a way that there are no errors?

Thank you very much for your help

[Brianmoooore]

I'm at a bit of a disadvantage here, because you're asking about something that has been wired by third party, not something wired by BMW, which has now gone wrong.
All I can suggest,is that you check for 12 volts + on pin 85 with the aircon. switch on, falling to 0 volts with it off, and for 12 volts+ on pin 86 with the aircon. on AND the compressor clutch engaged, and for 0 volts with the aircon. still on, but the clutch not engaged.

[selespeed]

I'm at a bit of a disadvantage here, because you're asking about something that has been wired by third party, not something wired by BMW, which has now gone wrong.
All I can suggest,is that you check for 12 volts + on pin 85 with the aircon. switch on, falling to 0 volts with it off, and for 12 volts+ on pin 86 with the aircon. on AND the compressor clutch engaged, and for 0 volts with the aircon. still on, but the clutch not engaged.

Brian, the engine is a e36m42 that' swapped into my e30. but the a/c wasn't done properly and so i asked another BMW mecanic to do the job but i think he didn't do a professional job. he just did a "short cut" to make it work but introduced constant error 85 i found out later.

any, i am going to ask an electrician to check based on the info you provided. i thank yuo very much for your help and will update status here once this is done.