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Indy shop also recommended installing a head unit. I sourced one off ebay that had been tested. Shop said there is still an hvac fault even after installing it. The radio hasn’t functioned for maybe a year. Shop says the next step is to replace the radio.
I matched up the drawing from rkw77080 with my drawings for the RX330 for the Nav Dvd Ecu you purchased(RX330) and the wiring is a match- however-
the drawing only shows about half of the wires available so I can't confirm 100%- only what is shown.
And from there it gets different.
On the RX330 there are 2 pairs of comunication wires coming from the Gateway ECU- one pair directly to the
Multi-display for AC/info and one pair thru the radio for Sound/Nav/etc to Multi-display and Amp and Nav Dvd Ecu,
and Camera Ecu, etc.
According to drawings provided you have only one pair of communication wires coming from the Gateway ECU directly to the radio- and from inside the radio it splits forward to the Multi-display and backward to the Amp- where it
then inside the amp splits again to the Nav Dvd ECU and Rear A/C controls/Audio.
Because of this and if the drawings aren't leaving out any details it looks like your no A/C controls communication
problem can involve the Gateway ECU, the Multi-display, and the radio, and maybe more I don't know.
PS- I gave it my best shot I wish you success.
Last edited by Margate330; Jan 14, 2020 at 06:46 PM.
The Code B1248 indicates that the problem is the Gateway ECU. The Gateway ECU is at the center of the communications among several components, including the radio and A/C - both of which are not working on your LS. The B1248 code is output when communication stops between the gateway ECU and the AVC-LAN circuit. (This is according to the attached pdf posted by rkw above.) The pdf describes procedures to check / verify the connection of the gateway ECU by putting the system into "service check mode" which, for a LS with navigation, can be found on page DI-1595 (also posted in a pdf by rkw above). Note that one of the tests is to check the wire harness for continuity with the "radio and player" - one of the symptoms you are having with the radio not working.
Before you replace any other component part, I strongly recommend that the Gateway ECU be tested or simply replaced.
Well, with the used amp installed the climate control, radio and nav now work.
Skip[/QUOTE kindly assist me I have a same problem
Well, I have pretty much the same problem again.
I did replace the AC compressor and the AC control valve that came with it. So at least the climate control runs at the last setting it was at when I turn the car off.
But usually I cannot use the nav screen to change the climate control settings when I start the car. Sometimes after the car is driven for at least 20 minutes, then I can adjust the climate control.
I have been told by others that likely there is an electrical short.
The used radio/cd player stopped working a while back. Not sure if its the used amp.
I’m out in a remote area and several shops here won’t work on it.
The issue is most likely with your radio/cd player (hard to say for sure without seeing it). There is a 6 pin connector on the radio that has 2 sets of communication wires. If you unplug the 6 pin connector on the radio, the message "Check the connection of the air conditioner" will pop up. I know this because I installed a stereo in my 2001 LS and left the 6 pin disconnected to see what would happen. The gateway ECU feeds a CAN signal to the factory radio, and then the radio connects to the multi display. If there is an issue with the radio, and the multi display cannot communicate with the gateway ECU, then this message will appear. I've attached a wiring schematic outlining what I've described above.
