looking for the no-nonsense answer (and myabe a handy diagram Bobby ).. how is the air con circulation controlled? I ask because my passenger side TEMP control appears to be controlling the TEMP of the air coming out of the DRIVERS side vents.. and before I have the fairytale explanation/conversation with the Stealer.. I'd like to understand how the mechanism actually works? I assume some sort of motorised flap?


I've done the self test and get 10 flashes from the LED, so clearly something is wrong....

(The self-test can be initiated by pressing and holding the ECON and RECIRC buttons while turning the ignition switch to the ON position. The control module will then compare the current motor position with the values stored in the module and will indicate an error by flashing the ECON LED (light emitting diode). )


thanks in advance!

the system is all electronic - i.e. the control panel connects to the AC system via a AC Harness

Side-to-side air circulation is controlled via independant Air Damplers (flaps) which are in turn controlled via Stepper/Servo motors - if you are changing the Passenger side airflow and it effects the Drivers side, then it could be a few things - one could be the harness has been connected wrong.

is it vice versa? i.e. does changing the drivers side effect only the passenger side?

Kaine

Are the 2 sides set to the same setting or close to the same? There is a limit to the side to side difference, but my owners manual is outside in the car and it is cold and snowing outside............ 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

thanks Kaine. 4c difference I think Tim.

Been over 7 years since I worked on the ac system but I think the servos are controlled over a bus system so incorrect wiring shouldn't be an issue - I'll ask a man who will know

Not meaning to imply anything, but how do you confirm that the "passenger side TEMP control appears to be controlling the TEMP of the air coming out of the DRIVERS side vents.." ?

OK, you've done the self-test. Did you then turn the ignition switch to the OFF position and then back to the ON position again?
Do this and observe the operation of the programmed defrost LED.
If there are errors present, the programmed defrost LED will flash and the system will attempt to calibrate itself.

Another concern would be to see that the sunlight sensor is not covered or blocked. Inputs from this sensor are used by the ATC (automatic temperature control) module to adjust blower speed, temperature and distribution to improve comfort.

Quote:

Air Temperature Control

Air from the evaporator enters the heater assembly, where temperature blend doors direct a proportion of the air through the heater core to produce the required discharge air temperature. The two temperature blend doors operate independently to enable independent temperature selection for the left and right sides of the vehicle interior. The temperature blend doors are operated by stepper motors. The stepper motors are controlled by the ATC (automatic temperature control) module using LIN bus messages.

The ATC (automatic temperature control) module calculates the stepper motor position required to achieve the selected temperature and compares it against the current position, which is stored in memory. If there is any difference, the ATC (automatic temperature control) module signals the stepper motor to adopt the new position.

Air temperature is controlled automatically unless maximum heating or maximum cooling is selected. The required air temperature may be adjusted between 16 °C (61 °F) and 28 °C (82 °F) using the air temperature control switches. The control algorithms then attempt to maintain the desired set temperature.

Turning the temperature switches fully counterclockwise gives maximum available cooling. Turning the temperature switches fully clockwise gives maximum available heating. When maximum cooling or maximum heating is selected, the comfort algorithm adopts an appropriate strategy for the air distribution, blower speed,
A/C (air conditioning) and air source functions, except where a function is under manual control.

The temperature control of one zone can be compromised by the other zone being set to maximum heating or maximum cooling. True maximum heating or maximum cooling can only be obtained with both controls set to the same maximum state.

When the economy mode is selected, the automatic temperature control function still operates, but with no cooling capability the minimum discharge temperature achievable will be ambient air temperature plus any heat pick up in the air intake path.

simples... both dials set to the red dot (max temp) and air directed to face vents - all vents blow hot, as expected. Dial down the passenger dial to 26... right most vent starts blowing colder air (right most in a RHD vehicle i.e. drivers window side vent)

reset both to red do.. all vents hots.. dial down the drivers dial to 26, both drivers vents blow colder air, passenger vents unaffected

that cant be right, surely?

rrsboy

in your test, when you dial down the passenger dial to 26, does the passenger side vents expel cold air too (like it should)

The control system in the RRS/Disco actually resets the door positions every 2 weeks to take into account wear and disalignment so it shouldn't be an air leak. It could be either a software problem (in which case ask the dealer to remap the panel) or a stepper motor fault (which can be checked via diagnostics at the dealer).

Kaine