Power supply problem to the MFD?

I once installed an aftermarket audio thingy in my Gen 1 that messed up the network communications between the MFD and other parts of the car until I found the mistake in the wire harness it came with.

The symptoms of those disrupted communications were very much as you describe.

Any interesting aftermarket thingies on the car?

 

Puzzling.

 

Bought the car new? Or used Salvage title? Messed up wiring.
Don't know where you live but is car undercarriage very corroded? Corroded under dash? Corroded ground connections.
Any signs of mice in the cabin air filter or in the trunk? Mice damage to wiring.
Is your dashboard combo meter going out too?

Something going on with the AVC-LAN.

The Gateway ECU provides info to the mfd. Gateway data comes into pin 4 & 5 on the mfd. make sure all the connections to the Gateway ECU are secure and clean. Unplug its connectors and look closely inside each connector for corrosion. When you take the connectors off apply some contact conditioner to the plug I use CSP spray grease. It will keep moisture out and prevent corrosion. Make sure all ground connections under the dash are not corroded. Unbolt them sand them down apply grease and bolt back on.

Next move is getting a used Gateway ECU and swapping it in.

In the meantime take your gateway out and take the cover off it and see if there's any corrosion on the circuit board. It may be repairable if corroded. Take the glovebox out and its located to the right of the glove box. On the right side of the glovebox is a big metal square box that's the Hybrid VC ECU. The gateway is a little box right above it mounted diagonally. Its much smaller than the Hybrid ECU.

Good luck nebulous issue.

 

The FIRST thing to check whenever electrical "weirdness" starts happening with these cars is:
THE 12 v BATTERY and it's connections.

 

Also, there are system-check screens on the MFD that will tell you about any AVC-LAN or gateway communication errors.

Most of the posts on PriusChat about those screens are made by new owners who stumble on them and get all excited thinking they've found a built-in alternative to a Techstream rig, and they haven't, because those screens are only of any use for this sort of problem. But every now and then, along comes somebody who's actually having this kind of problem, and then they're useful. Very helpful while I was chasing down the comm problems from that iPod thingy.

 

I am totally lost and broken.
I have prius 2004. Bought feb 2022 and was happy because its one owner car with 114,000 and 41 carfax histories.
The only issue was with the MFD. No access to climate control, no hybrid battery status on screen. Whenever press climate button, error message shows external system not connected. Press audio button shows audio off message
Mfd has been repaired by autobeyours and bench tested. I replaced network ecu(gateway ecu) right above the glovebox,
Radio replaced(not after market) , navigation box under driver seat replaced today, 12battery replaced 4months ago.
No after market things on car,
MFD, radio, gateway ecu, navigation box under driver seat ,12 battery replaced.
Everything works perfect on car except the MFD,
Connectors of MFD and the one which are close to MFD are cleaned with connector cleaner.
Ground points checked and cleaned under dash.
What else should i do

 

Take it to a dealer for a proper diagnosis and repair.
Or get a newer model on which everything actually WORKS.

This is the kind of thing that often happens when you buy someone else's problem.
IF......the fix really was fairly easy and straight forward. the seller would have done
it already.

My advice is: NEVER buy a used vehicle when the seller says "It only needs.......ANYTHING."
Unless you enjoy pain.

 

You can also post screenshots from the MFD diagnostic screens showing the network check, and start reviewing the "multiplex communication system" section in the repair manual, and the related parts of the wiring diagram.

Toyota Service Information and Where To Find It | PriusChat

 

Agree.
Will go to the dealer and see what he say,
As i said almost all the parts( mfd, radio, navigation box under driver seat, gateway ecu, has been replaced) have been replaced and i doubt it that there is problem with wire harness.
Will post once have an update from dealer.
After replacing the navigation got the same error as year before shown in the pictures

 

Have the same error or codes i got an year ago after doing alot on this issue.

 

With so many NCON (not connected) results on that screen, it is no surprise to have many symptoms of things not being connected. Naturally, you will be unable to control audio when the audio H/U is not connected, and unable to control the climate system or see battery status when the gateway is not connected.

It looks as if you have already replaced several of the items (audio H/U, gateway, nav unit) that are shown on this screen as not connected.

So, assuming those other units are not all broken, I would strongly suspect a problem in the wiring that connects them all to the MFD. The "multiplex communication system" section in the repair manual, and the related portions of the wiring diagram, will be where you find the information on troubleshooting that.

Toyota Service Information and Where To Find It | PriusChat

 

The strange thing is that in last june and july MFD started to worked when the temp was 90 degree outside or when the cabin was too hot

Last year during june and july when the car was parked in the sun , the cabin was too hot and outside temperature reached 90 degree, everything came up on MFD and worked untill i switch off the car.
I thought that could be due to corrosion in connectors, since then all the connectors have also been cleaned.
Now what left is to check the wire harness.
Will keep posted.
Thank you for your response

 

sounds like bad solder joints in the MFD

 

@Muhammad tabish
Did you ever find a solution to this problem? I am having similar issues where my MDF doesn't connect to anything but EVM. But I am also having an issue where all radio and nav button's on the steering wheel don't do anything either. But this all started after I replaced my evaporator and took everything in the dash apart.