Will not start, no check Engine light, no dash lights, no Multi-function display?

NAVI SINGH DEOL

MEMBER
2008 TOYOTA PRIUS
199,000 MILES

It doesn't lock and unlock from key fob anymore. I have changed the key fob battery. The only things that work are headlights and dome lights work when door opens. I checked voltage at front jump point n back at the battery. It’s 12v and all the fuses are good. Also tried putting in new battery but no difference. What can I do next to diagnose the problem?

5 Replies

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

This sounds like the BCM when out, but to be sure let's run a CAN scan which is easy. You can get a CAN scanner (Controller Area Network) from Amazon for about $32.00.

here is a video to show you how:

https://youtu.be/u-4syLc-ifQ

and

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Here is how to change the BCM out which you can search Google or eBay for a rebuilt unit that comes preprogrammed. Check out the images (below). Please let us know what happens.

Images (Click to make bigger)

SPONSORED LINKS

Was this

answer

helpful?

Yes

No

-1

Monday, January 16th, 2023 AT 10:38 AM

NAVI SINGH DEOL

MEMBER
4 POSTS

It gives error it’s not connecting to obd2 scanner.

Was this

answer

helpful?

Yes

No

Monday, January 16th, 2023 AT 1:09 PM

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

There is an IG2 relay I would swap out which supplies power to the system that is not working. The relay is located in the fuse panel under the hood on the left side.

Here is a guide to help you test it and the location in the images below:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the images (below). Please let us know what happens.

Images (Click to make bigger)

Was this

answer

helpful?

Yes

No

Monday, January 16th, 2023 AT 3:53 PM

NAVI SINGH DEOL

MEMBER
4 POSTS

Relays are good. I had Prius mechanic check it and he said my remote doesn’t have the smart chip inside or I lost it when replacing the battery. But the thing is I never opened that side of the remote where smart chip sits. It’s not the original key fob of the car and it’s the only one I have. Now he’s telling me I need a new key chip and he will reprogram the key. I don’t understand how the key worked before without the chip.

Was this

answer

helpful?

Yes

No

Wednesday, January 18th, 2023 AT 6:39 AM

KEN L