2001 GS300. I’ve had electrical issues with this car in the past, I thought I was done with them.
So everything has been fine, zero issues whatsoever lately. Installed a double DIN stereo for my son and all the electrical gremlins are back. Steering wheel goes in and out but not up and down. Climate control fan not working at any speed. Immobilizer light flashing, car cranks but doesn’t start. Scanner hooked to OBD port says “no link”.
Put everything back to stock, same issues. Checked fuses and couldn’t find anything.
Any ideas?

 

There is a possibility that you have interrupted the digital communication link (MPX bus) between the ECU, body control modules and the stereo / climate control unit.
This bus has a "daisy chain" configuration in which data is transferred from one device to another.

 

If that was the case wouldn’t communication have been restored when I reinstalled the factory components again?

 

It should have been restored. Are you sure all harness connectors are in place?
And the second point is that it is possible that aftermarket components were connected to inappropriate circuits and burned the original modules or their fuses.

 

Not all harnesses. I reconnected the nav screen/radio/climate controls (ML system w/nav). Minor components such as hazards, seat heaters, etc. were left unhooked, as well as the factory amplifier. I used harnesses and didn’t splice into any factory wiring so the chances of burning up a circuit or popping multiple fuses are highly unlikely, although I guess not impossible. What I don’t understand is all these problems should be on totally separate circuits and not related at all. And the aftermarket radio works fine.

 

OEM amplifier is part of the digital communication link.

 

Well poop. I’ll plug it in tomorrow and report back. Thanks.

 

Put everything (everything!) back to stock. No change at all.

 

RE: ECU
Just jumping in with a question before I start researching:

Is there an ECU for 2006 Lexus Hybrid RX 400h?

Thank you in advance!

 

Okay, maybe some power fuses have blown. There are three main fuse boxes - under-hood next to the battery, under-dash driver side kick panel, under-dash passenger side kick panel. Check all fuses by removing them and checking for continuity.

 

Well this is embarrassing but I’ll share anyway to possibly save a headache for somebody in the future. And thanks for the feedback. I disconnected a harness in the passenger footwell area when I ran the amp wire through. Plugged it in and everything works fine. Now back to your regularly scheduled programming.

 

It's good that you found it. It was likely one of the power lines to the passenger side fuse box / body control module #2.

 

I believe you are correct.

 

This is not true. It does use communication, but it’s not in the daisy chain and the car will work without the amp or the head unit or the climate.