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I wouldn't consider the output test reprogramming anything. It's just a sequential set of tests for the different functions of the A/C. I found the various flap range information to be useful. Once you go through the test, they system goes back to it's normal operation.
BTW, enjoyed the at-home karaoke youtube videos, I have a few singers in the house.
I do understand the output tests, but it's safer to ask the controller to do the sweep. I do write software for hardware to work so I know what output tests do.
If you set the min and max range for the controller to sweep, your output tests should be included but when the controller is sweeping, it know what's to disable to do it while you're directly accessing the registers and change the content to force the outputs, other safety conditions may not be met, hence the problems did exist for some people.
Set hi or lo will force max heat or max cold.
Set vents to individual settings will force vents to operate individually and different combinations, these will sure covers all your output tests in a safe way. IMO.
Glad you have singers in the house, The Voice may have some new contenders :-)
Cheers,
Louis
Alright, it wasn't that easy, the left side is hot again today. The right side not as cold as last few days... I'll charge some today or tomorrow to see the first assumption low pressure is correct before doing anything else.
Cheers,
Louis
Paging Mr. Bally & TSHong and AC experts...
I used the AC manifold to check the pressure - they look low on both Low and Hi side. My working pressure when the AC is on and working -
low side above 30 and hi side above 200 when AC is on and working well
low side pressure is 80 and hi side is 70-80 when engine is OFF Now mine when off - low side is only 55-60 and hi side is the same 70-80 but when AC is on low side only 30 but high side never goes above 160. I did charge some more freon and watched the gauge but it still no dice.
The right side is ICE cold but the left side vent is still warm air. It was cold when idling but when driving it blows warm air. The left rear pillar and center vent blows warm air while the right are ice cold.
I started to read about the HVAC and get some ideas about the venting system but not really a clear understanding of how the system work.
When the AC is on, does the heat valve shut off the coolant from running through the heat radiator or the cold air flap should just close the heater core - and which flap is it?
Why when the freon is low, the left side blows hot air and the right side still blows cold air, what sensed and decide to blow hot air instead of cold to the left vent?
If I take the car to the AC professional and have the system evacuated and charged, will it fix the problem? I wouldn't mind paying $100 for them to do it if it fixes it.
Please give me some inputs before I tear down the left hand side flaps, temperature sensors and motors. Start looking at some D4's... prices are quite tempting. The wife gave the approval if the AC can't be fixed.
Cheers,
Louis
I know you don’t like vcds and have paranoia about breaking something, but I really think an output test will narrow down the possible problems. Yes, the controller can drive everything it’s full range, but it’s reliant on you knowing exactly what that output should produce in the form of physical airflow/temp. A calibrated finger is not very good at that.
With the output test, you can see what the actual sensor and actuator feedback is, and it’s this that matters. Your testing so far assumes that everything you tell the controller to do, the system is actually doing. However if you have a flap, sensor, actuator, or whatever that is only partially operational it’s not possible to easily tell if this is the case by feel alone.
Anyway, given your low pressures and lopsided cooling, I think the most likely suspect is low refrigerant. The system doesn’t contain much refrigerant to start with, and coupled with it being a variable capacity compressor, it’s performance is very sensitive to small changes in refrigerant quantity. Loads of posts on it over the years describing exactly this, and mine also did it last year. Although as it was summer, I didn’t play about for weeks pondering what it could be. Just drove it to my local generic repair shop that day, told them to do an evac and recharge. No fix, no fee, no brainer.
I know you don’t like vcds and have paranoia about breaking something, but I really think an output test will narrow down the possible problems. Yes, the controller can drive everything it’s full range, but it’s reliant on you knowing exactly what that output should produce in the form of physical airflow/temp. A calibrated finger is not very good at that.
With the output test, you can see what the actual sensor and actuator feedback is, and it’s this that matters. Your testing so far assumes that everything you tell the controller to do, the system is actually doing. However if you have a flap, sensor, actuator, or whatever that is only partially operational it’s not possible to easily tell if this is the case by feel alone.
Anyway, given your low pressures and lopsided cooling, I think the most likely suspect is low refrigerant. The system doesn’t contain much refrigerant to start with, and coupled with it being a variable capacity compressor, it’s performance is very sensitive to small changes in refrigerant quantity. Loads of posts on it over the years describing exactly this, and mine also did it last year. Although as it was summer, I didn’t play about for weeks pondering what it could be. Just drove it to my local generic repair shop that day, told them to do an evac and recharge. No fix, no fee, no brainer.
Its been perfect ever since.
+1. FWIW, when mine went low, the performance was also erratic side to side and vent to vent. It was only about half full when they evacuated and refilled it with no known leaks, and then perfect right afterward and since.
Other corner case possible reading OP's recent descriptions might be a heater valve staying open more on one side than other. A/C only isn't truly two sided like the heater cores are--it's really just moving door magic for A/C. But, yes the operating logic is such both heating (water flow) and A/C can be on at same time--high low temp split, defrosting, humidity, etc. As dvs dave said, I would just buck up for the A/C service and hopefully be done w/ it.
Hi Louis, had the same problem sometime ago. i was able to resolve it by opening the HVAC hot water valves beneath the engine ECU in the bonnet, i cleaned the valves with stainless steel cleaner greased it and coupled it. Its been fine since then.hope this helps.
04-01-2018, 02:31 PM
