No start - instrument cluster flashing randomly

[acer1001]

I have been browsing here for a few months since we picked up a 2004 GX470 with 71k miles about 6 months ago as the family vehicle. Have gotten a lot of good information and have been slowly doing some maintenance and upgrades. Installed a new double DIN head unit a few months ago and finally got around yesterday to installing the backup camera. Since I had the rear hatch open I decided to replace the rear hatch lock actuator motor as well. Hooked everything up and turned on prior to closing the interior panels and eveything worked fine (reverse lights, locks, backup camera, started up fine). So I closed up all the panels and go to start the car and I get nothing but random flashing from the dash once I get ignition to ON. I also get a steady clicking from the fuse area. Checked the fuses inside and engine bay (getting a lot of clicking from various relays as well) and I also tried to hookup to Techstream to see if any errors, but of course I get nothing (it can't connect to the vehicle). I disconnected the negative and positive for 20 mins or so and tried starting again with the same outcome. So I disconnected the camera wires from the reverse light (thinking maybe the GND wire was shorting somewhere to chassis?) and disconnected the negative battery cable for a while and tried once again... same flashing instrument cluster lights and no luck

. After a few more tries the instrument cluster is faded now though the battery still shows 12V. Anyone have any ideas? Gotta get the wifes vehicle back up and running

. I've got this sinking I'm screwed feeling and will have to tow to dealership 1.5 HRS away (or local Toyota dealer if they will take it).

 

[Onefastrx7turbo]

How old is the battery? Sounds like it could be battery related or possibly an ignition switch or main relay.

 

[acer1001]

Oct 2014 battery, tried jumping, no luck there. Doesnt feel like IGN switch, I've had to replace that before on another car. The vehicle recognizes the change from OFF to ACC to ON, its just acting like a bad GND is tripping out the ECU maybe?

 

[co4wheel]

Sounds like a short to me. Undue what you did before. See if the issues go away.

 

[acer1001]

Undid everything, tried again with no luck. Connected techstream and it is unable to read any of the ECU's. Possible I fried the ECU?

 

[acer1001]

Does anyone know if I can replace the ECM (plug and play)? What is the link to the immobilizer, is it a matter of reprogramming or is it new immobilizer and locks along with ECM?

 

[GXO]

If it is the immobilizer it should be the light with the key lit...

 

[acer1001]

Thanks everyone for the advice! Guess I should have listened more closely instead of chasing ghosts. After two days of pulling fuses and relays and redoing wiring, i borrowed a charger and a few hours later, it cranked up. I didn't know low voltage would cause the instrument cluster to act nuts and throw a ton of check engine codes. Had about 12V before I put it on the charger. The back up camera and door lock motor both work great. That'll teach me not to overanalyze the problem next time!