Living in the tropics means running with air con day and night. Unfortunately, mine isn't very reliable on my 2001 XJ8. Initially it runs just fine, but after about 20 to 30 minutes (either in auto manual mode) the air flow backs off and the cabin warms up almost instantly. I can hear the blower running and change speed as I dial in for more air, but the flow remains at a trickle. I need to turn off the AC and wait 5 minutes for the air flow to return before ending up the cold air again.

Any thoughts?

You need a Freon charge: google AC freon charge on Jaguar XJ8; should see a great uTube video that shows you how to do it. Kit should be available at local parts store or can order it on line from any US, Brit, or Aus site. Kit will come with Freon and connector components. Should take five minutes and freeze meat afterwards UNLESS you have a leak or wornout compressor and drier (then it gets expensive).

There is also a thread on this forum that shows how to troubleshoot from the ac switches.

Richard - is your system running in recirculation mode for the first 20- 30 minutes and then the recirc shuts off and this is when the air flow backs off? If this is the case then you may have a blockage with the fresh air intake duct that starts at the base of the windshield.
When you feel the air back off look to see if the light is now off on the recirc button. If it is turn it back on and see if air flow and cooling instantly returns.

Thanks for the helpful advice but I already had the gas recharged but the fault persists...

When the air flow slows down I can hear the blower fan working as normal. The air flow slows down whether in auto, manual or recirculating cabin air... to get air flow back, I shut down the AC, turn up the fan speed and after about 3 to 4 minutes the air flow returns...

Could this be a sticking flap in the air chamber, a dodgey temperature sensor, or something else? I am reluctant to attempt pulling the consol apart, but fear this might be necessary...

You could check for fault codes, see if that leads somewhere. You could even try function test.


This simple 'first line check' will allow you to ascertain whether the system is operating within its design parameters, without recourse to PDU.

1. With the engine at normal running temperature.

1. Presss AUTO to display selected temperature and illuminate AUTO and A/C state lamps.

1. Rotate FAN to increase or decrease lower speed, verify bar graph representation.

1. Select A/C to toggle on or off. (The compressor may be inhibited by the ECM should either the engine temperature NOT be normal or the ambient be < 2° C).

1. Select RECIRC , state lamp should be lit and the recirculation flaps open.

1. Select distribution buttons in turn, verify correct air distribution and relevant state lamp.

1. Select DEFROST , check max fans and air to the windshield.

1. Cycle TEMPERATURE to ' HI ' and ' LO ' to verify demanded variations and display operation. Note that extremes will provide max heat or cold independent of in-car temperature.

1. Select EXT to toggle between ambient and control temperatures.

1. Select F (where fitted) and R - noting exterior mirror; verify timer and operation (glass may be warm to the touch)

1. Initiate system 'Self Test' to display stored faults should any of the above not perform as stated.

Another test...


Actuator Check Procedure
The system self test procedure drives all the actuator motors, to check their operation. If an actuator is operating incorrectly or operating outside of its limits then a fault code will be present.
Before commencing with the actuator check procedure, ensure the car is operating under normal conditions.

1. Switch ignition OFF.

1. Press and hold the RECIRC and AUTO buttons simultaneously, switch ignition ON and run the engine.

1. All the control panel LEDs and all LCD segments will flash on and off. Any function LED indicator which does not flash on / off suggests a fault condition within that area of the panel or, with the LED.

• Any LCD element which fails to flash on / off indicates a fault within the display element or panel.

1. Press AUTO

1. Press RECIRC button to instigate actuator check mode.

1. Press FACE to cycle through the actuator mode conditions 20 to 27.

1. Press the FAN button to restore normal operation with default panel settings, ie AUTO @ 24°C

Check for codes...


Fault Code Extraction and Deletion Procedure
Error information is stored in the A/CCM up to a maximum of 5 faults. Should a sensor fault occur there will be an audible beep and the message Er will be displayed on the control panel display for 5 seconds after ignition on. Please note that this will happen only once in any ignition switch cycle. The error source may be accessed by the following procedure
This procedure must be completed through one complete cycle, 1 through 6
StepResult#1 Simultaneously hold AUTO and RECIRC - Switch ignition to ONDisplay element check#2 Press AUTODisplay of stored fault (NUMERIC) code. If ZERO appears, there are no stored codes#3 Press FACEScroll through stored faults (maximum of 5)#4 Simultaneously press FACE and RClear stored fault codes (may need to be repeated for each fault)#5 Press RECIRC (Press FAN to skip actuator check)Initiate actuator check (Actuator codes 20 through 27 * )#6 Press FANExit error check mode

Let us know what codes you found. Hope this helps.

Hello Jaguarbitech,

Many thanks for the reply. I've run through your suggestions with the following observations:

The system seems to be working fine, except that the defrost doesn't blow hard, and the heater has never worked (no big deal living here).

I noted a fault '44' in the A/CCM

Any thoughts?