kylejohnston1

Calling all CCU experts out there!

I recently received the obd1 Scantool interface as a gift. Got the software installed and went to read codes on my C2. I was able to read and clear the mototronic and airbag system codes but I couldn't read the climate control system codes.

When I selected the climate control system in the drop down box, the scantool software would continue to indicate "connecting" on the laptop screen but would never actually connect and allow me to read codes.

A fellow rennlister was kind enough to let me borrow his spare ccu to be swapped with mine. Once I dropped in the spare ccu, I connected the interface and was immediately able to read and clear my climate control codes without any issues.

So, it appears there is an issue inside my ccu that prevents the codes from being read. Any ideas on what this might be? I'm decent with a soldering iron but I'm not great at the diagnosis part. If I am unable to fix the unit myself, I will send it to Loren or Otto's Venice for repair.

Thanks for any suggestions!

mojorizing

It could be a bad solder joint on the input connectors at the “K” or “L” pins, or power regulator on the pcb, or even the micro processor. In any case, you’ll have to gain access to the 2 pcb’s in the chassis. You take off the sample fan , the front plastic façade, maybe a few screws and then you slide it out to do a visual inspection. Beyond that you’ll need a de-solder station to split the 2 pcb’s apart. Though at this point, I think you might want to call the repair places you listed – they might want the unit unmolested. Price out a refurbished unit versus the price to repair your unit, etc. They’ll might even exchange yours for a working unit plus some $. If that’s the case be sure the new unit
has all the ***** and buttons. If it comes down to it, I’d be willing to buy your unit to offset the price of a refurbished. I enjoy fixing those things.

Kevin

kylejohnston1

Looks like rebuild prices have gone up. I was estimating around $350 after reading through older posts but some of them were 5-6 years old. Loren quoted $475 and Otto's quoted $550-$600.

My unit works just fine except for communicating with the scantool so I'm not sure if the rebuild would be worth it. On the other hand, it would be nice to access my a/c system codes. I'm also considering buying a used 993 ccu and keeping mine as a spare.

Loren mentioned that Porsche might have used a different firmware on my ccu than the firmware that was used on the ccu I borrowed. So although the part numbers are the same, my firmware could possibly be what is causing the issue?

Kevin, I'll let you know if I end up selling it. Send me a PM with a price if you would be interested in tackling a rebuild for me, though I'm not completely sure that would fix the connectivity issue!

mojorizing

I've worked on an early model ccu w/ 964.xxx- part number and I was able to connect, read and cancel codes but was unable to get beyond that ( no actual values, actuator tests, etc. )

I do have a 993 model that's currently apart that had a faulty servo driver chip - now fixed, but I was keeping that as my own spare, but I could sell it. I'm not at home now - will be after the 15th. Let me think about it and I'll PM you on price, etc.

Also, not to put you off( not to start a members/non members rant, god forbid), but I'm more comfortable dealing with members...have you considered joining?

Do you still have use of the loaner CCU? Are you in dire need of a CCU?
Also, if your CCU as it should, you're actually are in a better situation than some of the members.....