Help with wiring for F30 - intermittent air conditioning after timing chain (80436e)

[leandro_hernandezj]

Two months ago, in April, before it got hot in Pennsylvania, my wife had the timing chain replaced on her 2012 328i. She had a 2025 i4 by Mother's Day. The private sale of the 328i is something I've been meaning to do for some time now. She was behind the wheel a few weeks back when the air conditioner refused to turn on. It was OK the following day, and on the few occasions we've driven it since then, too. Everything changed last weekend when I took a stranger for a spin. In the middle of the test drive, the air conditioner stopped functioning. It probably shut off when the man hit a pothole.

"80436E compressor clutch: line disconnection or short circuit to B+ "is the message that appears after I've done some investigating. It seems like something was reconnected incorrectly or a wire was pinch when the shop did the timing chain job. I'm suspicious of that. Someone please give me a wiring diagram or tell me which connectors I need to double-check. Much obliged.

[hassanxm]

Is there no guarantee?

[leandro_hernandezj]

I intend to contact the store today; however, it has been approximately two months. Before I spend a few hours taking it in, it would be helpful if I could just check the connectors quickly on my own.

[leandro_hernandezj]

They said that the timing chain job isn't near the compressor/clutch wiring after talking to the shop. They think the compressor is malfunctioning or that there is insufficient refrigerant.

[hassanxm]

This is the ECU variant, ECU label, and fault information for the following modules: fem_20, the front electronic module, and bdc, the body domain controller. The 80436E compressor clutch is causing a line disconnection or short circuit to B+.11 Controller for the Body Domain View 80436E—Valve for Coolant Changeover: 8.0436E Compressor clutch or changeover valve: Line disconnection or short circuit to B+ Body domain controller (bdc_g05): Break in wiring or short circuit to B+ Front electronic module (fem_20): View 80436E Magnetic coupling of the air conditioning compressor or changeover valve: Break in wiring or short circuit to B+

[leandro_hernandezj]

The front electrical module displays the code. [top line] Could you recommend a reliable method for testing the voltages during the occurrence of the issue, given that it occurs intermittently?

I located the AC connector this morning and connected and disconnected it. It felt slightly loose when I took it out compared to when I reinserted it. To find out if that resolved the problem, I must drive it for a while.

According to this post/diagram, the clutch is controlled by the third wire on the AC connector.

[hassanxm]

Which engine determines the specifics. That will have been detected by the ISTA Test Module.