Recirculation turns off by itself - 2001 V70 cabin air

PatrickHenry · Post by **PatrickHenry** » 02 Feb 2012, 07:46

Hi,

2001 Volvo V70: The recirculation button (air conditioning system/heat/ventilation system) on my V70 has started "dropping out" (won't stay on) at random, turning off by itself and allowing outside air into the cabin. It used to stay on continuously, but something has changed and now it turns off after anywhere from 30 seconds to 10 minutes.

I tried searching the forums but couldn't find any leads. Any pointers/suggestions would be much appreciated.

Thanks!

Post by **fazool** » 02 Feb 2012, 08:22

I have a 2001 S60 . Mine turns itself off based on certain conditions - like if I switch to windshield defogger or if I switch the HVAC to auto control, etc.

PatrickHenry · Post by **PatrickHenry** » 03 Feb 2012, 07:10

Hi fazool - thanks for your comment. I know what you mean, but mine is turning off without me turning any switches. I'm just driving down the road and the recirculation turns itself off. Perhaps it could be that it is being inadvertently triggered by the windshield defogger, which, as you noted, does interface with the recirc somehow.

Do you have any idea what the nature of the interface is between the recirc and the defogger (i.e., electrical, vacuum, etc.)?

Post by **fazool** » 03 Feb 2012, 07:25

I am pretty sure (or at least, I think) its purely electrical. I think when the defogger goes on, a signal turns the recirc off.

PatrickHenry · Post by **PatrickHenry** » 03 Feb 2012, 08:15

OK, thanks. I suppose there could be some sort of short in the defogger switch that is erroneously passing a signal to the recirc to turn off ... I will keep that in mind.

Post by **jimmy57** » 03 Feb 2012, 08:19

There is a feature that can be turned on and off called timed recirculation. If you push and hold the recirc button for over 5 sec it toggles this feature on and off. If in timed mode pushing and holding puts it back to normal and vice versa.
Timed is the default. Recirculation should be used sparingly to assure windows stay clear in cool weather as recirc air will let them fog even though the heat is up(note all those toyotas and hondas that have manual recirc control driving in cold weather with fogged windows). Recirc air gets wetted by our breathing and since no outside air is introduced it will not be able to dry. Recirc also contributes to stinky evaporator odors as the fresh air door will be closed when car is off trapping air that could other wise move and dry the evaporator when parked.
Fresh air is also a contributor to more alertness in driving after prolonged driving.

PatrickHenry · Post by **PatrickHenry** » 03 Feb 2012, 09:17

Hi jimmy57 - thank you for that information! I will see if I can toggle timed recirculation.

PatrickHenry · Post by **PatrickHenry** » 03 Feb 2012, 09:24

Thanks again. Searching for the terms "timed recirculation" and "volvo" led me to the following...

TNN87-40-2001-10-05 Title: Climate Control Module Recirculation Timer Function.
This information is intended to assist in better understanding the Recirculation Timer Function found in the Climate Control Module (CCM) in these models. The CCM has two recirculation modes: normal and timed. In normal mode, when the recirculation button is pressed, the system recirculates the interior air until the driver takes further action. In timed mode, when the recirculation button is pressed, the system recirculates air for 5 to 12 minutes, depending on outside air temperature, and then reverts to fresh air. Timed mode eliminates the need to manually revert to fresh air by pressing a button.
Note: Vehicles equipped with the Interior Air Quality System do not have the timed recirculation mode.

ACTIVATING/DEACTIVATING TIMED RECIRCULATION MODE S/V/C70 Vehicles: With the key in position II, press and hold the Recirculation button for three to five seconds.
- If both the green fresh air and amber recirculation button LEDs begin flashing, you are entering "timed" mode.
- If both LEDs shine steady, you are exiting "timed" mode.

Mode Memory: If the vehicle is switched off while recirculation timer mode is active, timer mode will still be active when the vehicle is restarted

Post by **jimmy57** » 03 Feb 2012, 13:22

Says the same thing but was something I found where someone had posted the owner's manual:

Recirculation

Press this switch to engage the recirculation function (air in the passenger compartment recirculates - no fresh air enters the compartment). The LED in the switch will light up to indicate that the function is engaged.

· Use this function if the outside air is contaminated with exhaust gases, smoke, etc or to heat/cool the car quickly.

· Recirculation should not be used for more than 15 minutes. If your windows begin to fog or mist, make sure that the recirculation function is switched off.
· Selecting Defroster automatically switches recirculation off.
· Timer function: (cars equipped with the optional Interior Quality system do not have the timer function) Pressing and holding the switch for at least 3 seconds activates a timer function. The LED in the switch will flash for approximately 5 seconds. Recirculation will then always operate for periods of 5 to 12 minutes, depending on the ambient temperature, after which it will switch off automatically. Pressing the switch at any time during the recirculation period will disengage the function and allow fresh air into the passenger compartment.
Press and hold the switch again for at least 3 seconds to return the button to its original function (i.e., recirculation will remain on until you switch it off).

PatrickHenry · Post by **PatrickHenry** » 29 Apr 2012, 12:20

jimmy57 - thank you so much for getting me on the right track with this! I need to re-read the owner's manual ... I would never have suspected that this was a settings issue (as opposed to a mechanical/electrical problem).