Monday, August 16, 2010 - 09:20 am, by: Brian Thompson (Brian_thompson)
I'm stumped, I have no air.The climate control is not out .all the settings work that I can see I've done the diagnostics .I get code 00 .I took the car to a local mechanic and checked the freon all was good. then he took out a ohms tester and checked the pressure switch good. then he took the mct relay out and jumped the socket and was able to get the clutch to work. air blows cold as ice .then he said the relay was good he thought the socket wasn't receiving a ground from the controller or e c u can the climate controller be out and still display all the functions and why would there not be a ground signal going to the relay please help
Monday, August 16, 2010 - 09:28 am, by: Matt Petersen(Mattmannz)
There are often a bunch of sensors that are used by the climate ECU to determine whether or not to activate the compressor.
High pressure, low pressure, cabin temp, external temp, compressor speed and others. Its likely that one of these sensors will be signalling the climate ECU and it therefore won't turn on the compressor.
You really need to see the signals that each of the sensors are outputting to check what the ECU is receiving and see why it won't turn on.
I haven't seen a detailed climate ECU schematic so can't comment on specific sensors but in other jap imports I have worked on without a detailed diagram it can be very difficult to trace the faults.
Last import Corolla oddball I worked on we made a circuit to always power the compressor when the AC button was pushed effectively bypassing the climate ECU. Air worked fine but there was a fault that could not be found so we went that way. Bit of a last resort though as troubleshooting can burn hours.....
Monday, August 16, 2010 - 10:28 am, by: Brian Thompson (Brian_thompson)
Can you tell me if its climate control module sending the signal to the magnetic relay or is it the main e c m that sends the signal it gets from the climate controller hope that makes since thanks
Monday, August 16, 2010 - 10:33 am, by: Matt Petersen(Mattmannz)
I haven't seen any detailed wiring diagrams or schematics for the UZZ models so not sure.
Often the climate ECU controls the relay but also signals the main ECU so that idle speed is increased etc, this might not be correct for the UZZ/JZZ's
Monday, August 16, 2010 - 03:34 pm, by: Don Bagnall(Baggs)
Brian,
I suggest you take the car to the nearest Lexus Dealer, and they can plug it in to their Diagnostic analyser, which should find the problem fairly quickly (cheaply).
The nearest one to you is this place.
Lexus of Shreveport Bossier City 2901 Benton Road Bossier City, LA 71111 Phone: (888) 226-6084 Mon-Fri 8:30am - 7pm Sat 8:30am - 6pm Sun Closed
And your nearest Toyota Dealer (they normally have the same diagnostic equipment)..........Is.
Yokem Toyota 1199 E. Bert Kouns Shreveport, Louisiana 71105 877-438-4066