issues with either fans or climate control module

[rfelker]

For the past month Ive had some weird rad fan, climate control issues. When the car starts in the morning sometimes the fans come on. They go off about 5 minutes later. But the really weird part the fans stay on if its 75 or above after the car has been sitting 8 hours. Also the climate control will not turn on. I have replaced the following-
thermostat
fan relay 219 and other 393 have been ordered.
changed out both my coolant sensors.
anyone had same issues?

[texasboy21]

Scanned the AC module for codes?

[rfelker]

yes no codes.

[texasboy21]

yes no codes.

If the climate control is malfunctioning there should be error codes. You will need a Vw/Audi specific code reader to access the AC module (vs the engine module that generic code readers can see).

[diagnosticator]

When the rad fan starts up and runs on high speed after cold startup, that usually means the ECU recognizes a cooling system performance fault. Did you check the ECU for fault codes?

[rfelker]

Im using vag-com and getting no codes when scanning well I do get a sensor error on rear right side but that's my speed sensor I need to replace.
But no codes on my climate control or fans. And what I don't get is the fans run for maybe 3-5 mins sometimes in the morning. Then everything is good when I drive to work. Get out 8 hours later start car and the fans run and the climate control is off. No power at all. Nothing has changed other than me replacing the tstat, coolant sensors. Did do the timing belt water pump in may.

[rfelker]

came home tonight scanned the car again and there are codes(sorry guys)
1 Fault Found:
01320 - Control Module for Climatronic (J255)
49-00 - No Communications

18043 - Powertrain Data Bus
P1635 - 008 - Missing Message from A/C Controller
Readiness: 0110 1101

[diagnosticator]

came home tonight scanned the car again and there are codes(sorry guys)
1 Fault Found:
01320 - Control Module for Climatronic (J255)
49-00 - No Communications

18043 - Powertrain Data Bus
P1635 - 008 - Missing Message from A/C Controller
Readiness: 0110 1101

Either the A/C controller is not powered up, or there is a fault in the Powertrain CAN buss wiring. What control module had the 01320 and 18043 fault codes stored, the engine ECU? or The Climatronic A/C control module?

[rfelker]

01320 is climatronic a/c control
18043- engine ecu

[diagnosticator]

01320 is climatronic a/c control
18043- engine ecu

In this case, it is likely there is a problem with the Powertrain CAN buss wiring between the A/C controller and the engine ECU.

[rfelker]

so I should be checking wiring from the climate control back to ecu or ac compresser to ecu? or both? and thank you.

[rfelker]

also noticed yesterday when tracking wiring from fan module to the connectors by the power steering there was a small burn mark on the wiring by the connector. I didn't notice this before. Its on the female end close to the connection. Bet they just don't sell the connectors to splice in.

[diagnosticator]

so I should be checking wiring from the climate control back to ecu or ac compresser to ecu? or both? and thank you.

The Powertrain CAN buss is a twisted pair of wires, orange/brown and orange/black.

[rfelker]

ok. Guess I know what Im doing this 4th july weekend. jeez
thank you again.

[coyne1981]

also noticed yesterday when tracking wiring from fan module to the connectors by the power steering there was a small burn mark on the wiring by the connector. I didn't notice this before. Its on the female end close to the connection. Bet they just don't sell the connectors to splice in.

Which wire is it on? Thick or small and color? I think i may have a connector as well. I will have to check when I get home.

[rfelker]

thick red wire.

[alimo20]

does someone know the answer to the question above?

"so I should be checking wiring from the climate control back to ecu or ac compressor to ecu? or both? and thank you."

either way - where is the AC Compressor to ECU wiring originate from?