Transit connect 2017 1.5 diesel lost comms...

[Abars]

Hi guys,
I have the above vehicle and the A/C was not working, i checked the pressures which were ok but re-gassed it anyway.
It still didn't work, i had it scanned but no codes, however, it was pointed out to me that there was no communication with the HVAC ecu, and although it shows multiple modules (eg. the auxiliary heater control module, the electronic air temperature control module, the front control interface module, the front control display interface module, the front distance sensing module, the image processing module, the image B processing module, the service interval reset, the trailer module and wheel alignment) It does not communicate with any of them, i am assuming that the electronic air temp control is the HVAC system as maybe is the the aux heater control module ( which i think maybe glow plugs in the cooling system, please correct me if I'm wrong).

My thinking is either a gateway, the can bus or a broken wire, my questions are, Has anyone come across this before? Or is there a topology map somewhere for the ecu's that maybe has these modules in a branch? Or a workshop manual with wiring diagrams? Do these suffer with water ingress anywhere?

I'm going to scan it myself tomorrow with the latest forscan to see what that brings up, but thought I'd ask the oracle first lol..

Any help appreciated

[metalworker0]

think those modules are all fed back to the BCM - body control module, so take a look at that .

you need diagrams of the can bus to work this out ..non here on connect on vehicles after 2014 - we haven't got them

you can download here workshop manuals on the custom and mk8 ..if you do a search ..that may help ..
as will be the same basic lay out

pm sent with manual for custom link

btw ...the manual can be searched with the words - CAN BUS

you'll find a lot of detail and explanations on how it inter-reacts with the AC

all the best.mark

[Altransit]

You've already checked the gas which is the single most common reason for it not working, and if there is gas in the system you can discount any damaged pipes or other gas holding components.

Have you checked that the aircon fan is functioning? If that doesn't power up, then nothing A/C related will power up. Failing that it may be that the compressor is U/S.

I've never found diagnostics to be helpful when tracing aircon faults.