mojorizing

Mojo,
I have a spare CCU w/ part # 964 659 047 00 - it has the single A/C button. It works on all functions and doesn't throw a code with my hammer.

The 993/ two button CCU must have a more capable cpu because my hammer will display more functions, ie. "actual values", "inputs", not just the "error codes".

I'm thinking I could send it to you for testing or exchange if yours is the 2 button. Or I can look at your CCU, I have 8 spare IC drivers.

mojo747

I have the two a/c buttons. I need to do something. Why do you have eight of these? Have any of them been rebuilt to avoid having this problem in the future? I'm afraid I'll fry another CCU if I hook it to these servos. If you can help me with this it would be great.
I've been tooling around in the car today. I thought I was in good shape because it was a cool morning and the vents were blowing cool. I dialed the temp to hot and it kicked the fan on and some heat bleed through to take the chill off. Nice. Fast forward to this afternoon. Much warmer out, fan is kicking on to cool motor, heat is bleeding by the closed flaps. Still cooking in the car, though not as bad.

mojorizing

I have 8 of the Siemens TCA 2465 IC's that tend to burn up. I have a spare 964 CCU and a 993 CCU that's apart that I'm tracing and generating a schematic, then I have a 993 CCU in my car.

Since you're a member in long standing (Jan '09), this is what I can do. Firstly, do you have access to a computer with a serial port? If so, I'll send a scantool and software and this 964 CCU, where you can get/clear/and cycle functions with the 993 CCU. If that CCU is NFG, swap out with the 964 unit. You won't be able to use the scantool to it's fullest due to the early version cpu in the 964 CCU, but you'll be able to do a visual on all the servos. If satisified, send the scantool back, or buy @ $130, and the 993 for me to fix and send back, or to keep the 964 for exchange. I would say it would be upwards of $200 to fix the 993 CCU. You're right, the servo's need to be in decent shape and stroked correctly. In dealing with servos of unknown status, it's best to have them disconnected from the linkage so that they can rotate to the limits without fetching up on a misaligned linkage.

Let me know what you decide.

warmfuzzies

Curiously my temps were skew whiff, the LHS ran cold, the RHS ran hot, the RHS servo would not operate at all, I took it apart, did the usual. Motor ran ok, even the LHS servo would not run in the RHS position...

Then I took some compressed air, and blew the internal CCU temp sensor clear, without taking it out of the dash.

Hey presto the whole shooting match now works, and I'm damned if I know why, but it just does.

Kevin.

mojo747

Here's my plan. I'm going to Gust the sensor, and if the miracle described by warmfuzzies doesn't happen for me, I would appreciate you sending me all that you described mojorizing. My old computer with the serial died. I'm sure I could get an adapter for the USB though. I can PM you my UPS account so you won't have any freight costs to send the stuff.

mojorizing

Ok, sounds like a good plan.

mojo747

mojorizing. Where in Norcal are you? I have family in Danville.

mojorizing

Arcata, CA .... Home of the homeless

mojo747

PM sent

ToreB

Mojorizing, I'm very interested in any schematics you produce of the CCU.

Best regards,
Tore

adrian crawford

hi all. i also have a ccu issue. when in the blue dot position (max cold) the front fans opperate at all the settings (1,2,3,4) as they should. however, when the temperature dial is moved (even slightly) off the blue dot, the rear heater blower kicks in and the front fans stop, giving out no air in the cabin! is anyone able to help me resolve this issue????? it would be much appreciated. thanx

ToreB

The CCU supervises the rear (aux) fan and shuts down the front blowers if it's not working properly.
Your fault Adrian is therefore most probably either a broken fan motor, a defective blower "final stage" electronic or a missing feedback signal to the CCU. Or a combination of these...
Cheers,
Tore