Help! AC blows hot on driver and passenger blows cold AC

[XLR&XKE]

Warm weather is finally here in Michigan and I find I have a problem with AC. Have any others had the climate control blow hot on driver only no matter where temp is set? Ac works for passenger.

 

[ccclarke]

The XLR introduced a new method of diverting air into the ducts, using a rolling film component. As the film is moved, holes in it direct air to the appropriate side and height. If the air was blowing warm on both sides, I would suspect the HVAC and more often the refrigerant level.

After ignition shutdown, if you sit in the car, you'll hear a whirring noise. This is the rolling film being repositioned. To test it, operate the HVAC control in all modes with the fan set to high and see what, if anything changes. Also listen for it to reset after you turn off the ignition. It appears it isn't moving as commanded or isn't getting the command from the HVAC.

Or. . .

A thermistor that senses the correct temperature on the driver side may also be suspect.

CC

 

[XLR&XKE]

Thanks CCClark for the reply, I was able to test all modes and they seem to be functioning in the different vents when changed. The initial air is cold and after it is on for about 30 seconds the air turns hot. I did note that when the feet and defrost mode was on it would be cold at both.
Do you know where I can test the thermistors and resistance at given temperature? Is it easy to replace?

Darrell

 

[ccclarke]

I'll have to hit the books and write something up tonight.

CC

 

[ccclarke]

There are a variety of sensors used by the XLR’s HVAC(Heating, Ventilation, and Air Conditioning) climate control system to regulate the temperature within the vehicle. The control unit --located within the center console uses four sensors (two each) on the driver and passenger side to sense the temperatures for each occupant.

Unlike the interior ambient temperature sensor located underand to the right of the steering column, (--which changes resistance withtemperature and is easy to troubleshoot) the duct sensors for each side are resistive, but use a voltage drop --read as counts, (just like the Folding Top Position Sensors) when the resistance changes, to be interpreted by a Tech 2.

Obviously, if you had access to a Tech 2, you could compare the two sides and instantly determine which sensor is faulty. Even easier, when running the HVACdiagnostic, the Tech 2 will detect which sensor is bad and issue a DTC (Diagnostic Trouble Code) identifying the culprit.

The Mode Actuator appears to be operating if you could get air to the lower vents, so it’s likely a bad temperature sensor. Nothing is guaranteed when troubleshooting remotely though.

Here’s what I would do: Have the car scanned and let the dealer tell you what component is bad. Assuming it’s a bad driver’s side upper sensor, you can order one online and I can walk you through the installation process. There’s no programming required for the temp sensor replacement.

I don’t know your skill level with tools, but you will have to remove the IP Cluster for the upper driver’s side sensor. If it’s the lower driver side sensor, you’ll have to remove the IP center stack and HVAC control unit. Neither job is hard, just time-consuming.

CC <strike></strike>

 

[XLR&XKE]

Sorry for delay getting back but many priorities.
I took the car to a dealer and they told me the AC needs recharging. I asked if they tested the sensors and they said they tested it? With much skepticism I allowed them to recharge the system. It seemed to work that day but the next time we drove it, back to hot driver and cold passenger.
I was able to take to a friend that is a Jaguar mechanic but has a TECH 2 for his SUV.


Test Results;
Ambient Air Temp. Sensor 69 F
Inside Air Temp. Sensor 79 F
Upper Left Duct Temp. S 236 Counts
Upper Right Duct Temp. 152 Counts
Lower Left Duck Temp. S 91 Counts
Lower Right Duct Temp. 117 Counts
Left Sunload Sensor 229 Counts
Right Sunload Sensor 229 Counts


We were not sure how to interpret the data but my guess is Lower Left sensor needs replacing?
Can you make sense out of this data?


On a side note, I had the dealer check the cruise control and it appears the radar detector is bad. They could not get the detector part but told me if I can find one they would install and program.

1. is programing necessary? Is it a plug and go?
2. Will a 2006-2009 unit work?
3. Were can I find one for a fair price?

Darrell