2005 V70 LIN-bus 1 signal too hight/signal too low... Topic is solved

rhubarb · Post by **rhubarb** » 21 Oct 2018, 08:54

Hi, VIDA shows CCM-DD01 LIN-bus 1 signal too hight/signal too low fault. As an effect, most damper motors dont work and the fan knob does not always regulate fan speed. I've read "every internet" on this fault, but had no luck in figuring it out.

Previously I had a recircluation damper fault, changed it, no fault about it now, but CCM-DD01 persists. Disconnecting left temperature damper changes nothing. VIDA doesn't even give me a fault about it. Bought a new damper - same. So either i bought a non-working one, or the problem is somewhere else. Disconnecting every other damper gives a proper fault in VIDA.

I also swapped the heater fan just in case. Didn't change a thing.

I have visually checked every visible wire (took out radio, climate control and compartment box). My car does not have heated seats, so the problem is not in the SHM (most threads in forums point to a faulty seat heating module).

So the short version is: most dampers don't work all the time, but the fan knob sometimes starts to work - have no idea why.

What else could I check? Any ideas? Plase help, i'm almost out of hope. Sorry if I am not clear enough, english is not my native language - please ask, I'll clarify any detail you need.

rhubarb · Post by **rhubarb** » 24 Oct 2018, 05:38

A little update, i have checked the thermistor that is behind the little grill in the ccm. It seems to give good readings, but with it's one wire disconnected i connected the CCM to the car and to my surprise, one of the dampers that was not moving at all started moving according to the left temperature knob which did nothing in the past. But it all ended after about 40 seconds. I'm starting to think that it is the CCM itself...

rhubarb · Post by **rhubarb** » 30 Oct 2018, 16:34

I managed to solve it. Changed one thing I did not change before - the CCM. 30€ for a used one and the CCM-DD01 fault is gone, the identification of components passes and calibration starts as it should. Case solved I guess. I hope this thread will be useful to someone in the future. One thing you should mind if you decide to swap the CCM is the serial number. Buttons doesn't matter.