98 V70 XC Electronic Climate Control issue

SuperDayv · Post by **SuperDayv** » 12 Nov 2014, 22:30

Good evening Volvo Guru's,

I have searched this forum as well as many others and found a couple similar situations but no resolutions. I apologize in advance if this is duplicated but i just searched 10 pages of forum threads related to climate control.

First noticed that the passenger side would only blow cold air, so I hooked up a VST, pulled codes and found cabin sensor and re-circulation codes, but no lights were flashing. I then pulled, tested, and then replaced the cabin sensor and the arm from the damper motor to the Recirc door which had broke. Tried to calibrate the motors and it either fails immediately or says complete immediately but nothing changes. I now have no heat anywhere and flashing AC light. The code that keeps coming back is ECC 236 - Recirc damper signal low. I have pulled the damper motors and left the scan tool up, and the scan tool reads correctly when making changes to the control head but nothing moves on the motor(s). I have 11.95V going into the ECC control unit(head) and 4.93v - 4.95v out to each damper motor. Check the ground, swapped motors around, checked both ambient temp sensors, etc. From what I understand about this ECC system, if one thing does not work, nothing will.

I am at a loss and getting frustrated. Has anyone ever come across a situation like this before? Any help or insight would be greatly appreciated.

Thanks in advance, Dave

SuperDayv · Post by **SuperDayv** » 13 Nov 2014, 07:33

Is there a way to check the damper motors? Could all of them gone bad when trying to calibrate? Since they share a ground and common from the ECC, could the first one, which ever that may be, be bad and preventing the others from working? Or am I over-thinking this?

Post by **combatkarl** » 13 Nov 2014, 12:22

Here's a post on testing (and cleaning) the damper motors https://www.matthewsvolvosite.com/forums ... 8&p=254621

This is from a '97 850 but likely the same motor is used in your V70.

SuperDayv · Post by **SuperDayv** » 15 Nov 2014, 07:25

Thank you combatkarl. My only issue is none of my damper motors are responding after I tried to adjust/calibrate the dampers using a VST. So it seems unlikely that they are all are bad or need to be cleaned. Does anyone know what the volts should be coming from the ECC to the damper motors? Common wire and signal wires? I have a schematic but not the ranges of each wire. Thank you in advance!

SuperDayv · Post by **SuperDayv** » 17 Nov 2014, 17:39

I replaced the ECC with one I pulled out of a junk car and now I am getting the OFF button and recirc button flashing 20 when turning the key and they go off. But still no movement out of the dampers. Granted I have two of them loose, not mounted but electrical connector hooked up.

Post by **combatkarl** » 18 Nov 2014, 08:53

[ Does anyone know what the volts should be coming from the ECC to the damper motors? Common wire and signal wires? I have a schematic but not the ranges of each wire. Thank you in advance![/quote]

This link maybe of some use for voltage readings. It's for an 850, but the damper motors are likely the same. http://www.volvotips.com/index.php/850- ... ce-manual/
See the PIN VOLTAGE TEST section.

caliwagon · Post by **caliwagon** » 05 Jan 2015, 11:06

Bumping this thread to see if there has been any resolution. I seem to be having the exact same issue. Only cold air out of the floor vents, with code ECC-236. Tried swapping the unit, but didn't fix the issue.

FYI mine is also a 1998 S70. Fan speed manual control works correctly, and A/C can be turned on and off, but still only cold air directed to floor.