Monday, February 18, 2008 - 10:19 pm, by: Aaron Mead(Aaron)
I have a problem, the head pressure gets well over 400 as the hydrulic engine fan is not engaging. It causes the compressor to open its relief valve and dump gas. This is where Im at:
********************************************* Allright. So, I ran the diagnostics, theres no stored or current errors, apart from the code '21' which relates to the solar/uv sensor. This is normal as its in a garage without light.
What we noticed is, that the hydrulic engine fan works fine in terms of keeping the engine temperature in check. I mean it never goes over the middle position, even whilst idling all day. It kick in to action as it normally would.
However, the AC system seems to be failing to trigger it to cool the condenser and the gas inside it, thereby keeping the head pressure under 400p.s.i. Its fails to do this and the head pressure increases above 400 and the compressor relief valve triggers and spews r134a to atmosphere.
Something strange though, is that if I press the front fascia of the climate control unit (centre console one, above the stereo) it triggers the hydraulic fan into operation.
So, my aim is to replace the entire unit with another one fo known working condition, and see if it successfully triggers the hydraulic fan to engage.
What do you guys think?
DOes anybody have a UCF11 climate control unit with rear aircon controls they want to sell?
I wonder what a brand new unit from toyota would cost
Friday, February 22, 2008 - 09:27 am, by: Rich O'neil(Kiwiinaus)
I have a spare one [ air con unit with rear controls ]but I'm not sure I want to part with it , it has a really good LCD display in it , I believe you can get a new LCD for it from Lexus special order from Japan at like $900.00 !! And now any good units that come up on Yahoo are $250.00 plus . I posted somewhere else about your problem and I don't think it will be the control or the ECU , possible of course , but not the most likely place , check out the pressure switch up near the filter dryer , replace this first , it is way easier to do and way cheaper and really should be done as maintenance anyway .
Friday, February 22, 2008 - 11:45 am, by: Aaron Mead(Aaron)
Cool, Ill check that first. I still cant understand why, if I press on the fascia of the Climate Control instrument panel, it triggers the fan? Still, Ill do that switch first. Order from Toyota I guess?