Potential short circuit maybe in the CAN bus

Well I found out something interesting but I must say at first that I did find the J9 connector and disconnected it and then did the test where I put it in IG-ON and then step on the parking brake ane then release it and the light on the dash did the same dance as they did on the youtube video. Not sure what that means. I did make sure that that wire on the connector connected to pin 14 on S9 using an ohm meter but I did not check if there was a short in the wire but not sure it matters now that we know the display dance happens even without that wire connected. So there must be something else connected to the cable that gets triggered when the parking brake gets put on.

The thing though that I think is new is that I was able to drive the car and there were no lights on the dash (except for the tire pressure light). But the way it happened was that I was going to put in a different battery and connect the new 10amp batter charger that I just bought but after I removed the battery that was installed I checked the voltage of each and the one I removed had a higher voltage so I just put it back in (I thought the other one had just been charged). Anyway after that everything worked, prior to that the MIL and other lights were on. I drove it around the block a few times and then realized the blinker didn't work so I went back home thinking it was due to the fuse I removed for the front wipers since they were going on seemingly randomly but anyway just as I got home all the lights went on in the dash including the MIL light (red triangle).

A few days later I checked the voltage using the menu/../display check on the display and it was 12.2 volts. I then installed a different freshly charged battery and the car started and there were no lights on the dash (except for tire pressure) and then checked the voltage the same way and it was 12.3 volts.

Anyway it seems the way to get things back to normal after the MIL light and others go on is just to disconnect the auxiliary battery, maybe for a few minutes and then reconnect it. I used to think it was because the different battery I put in was freshly charged and had a higher voltage, but not sure of that now.

What does disconnecting the auxiliary battery do?

I will drive it again tomorrow and see if I can repeat the pattern. I put a video of the working car on youtube here:

 

Well I actually have 3 batteries including a brand new Optima, and one of them is bad but the other non Optima charges to a higher voltage than the Optima and has actually been more successful at getting the car started than the others. I always look at the voltage before I make decisions, and recently bought a charger that puts out 10 amps so that I don't have to worry about the battery so much.

In the past I have used 2 different techniques for clearing the DTC's, on is by shorting pins 4 and 13 on the ODP connector and then putting the car in Ready mode and stepping on the brake 8 times in less than 5 seconds. The other method was to use the techstream software, that is why I didn't think just disconnecting the auxiliary battery would do it.

Thanks

 

When I remove the aux battery I use an Optima Digital 400 charger that is designed for Optima batteries (but can be used with other types) that I read does a good job charging batteries. The 10 amp one I bought to use when I am doing testing on the Prius so that the aux battery doesn't go below the minimum voltage needed for functionality, is that something that can ruin the aux battery? What if I just run it when in IG-ON mode?

Otherwise how do I avoid discharging at a fast rate the aux battery? I have had issues with the 2 fans going on in IG-ON mode and I haven't been able to diagnose that yet. I believe that over 25 amps were being drawn when these fans went on. On thing I tried was removing the relays that control the fans but it is nice to know when they go on to aid in the diagnosis.

Tim