Gen 2 Prius Won't Start-not the 12 V Battery

I don't think your hybrid battery has much to do with your 12V functions.
If there's not enough charge in the 12V battery, it won't activate the DC-DC converter, that charges the 12V battery, and acts as an alternator would in a conventional vehicle.

I'd really like to see someone design a gizmo that detects the charge in both batteries, and if the 12V battery is too low a state of charge, it would activate the DC-DC converter, effectively giving it a boost. The gizmo should also monitor the state of charge in the hybrid battery, so as to prevent running it down from repeated attempts to boost the 12 V battery. If someone made such a gizmo, I'd buy it, once I'm out of warranty.

 

I wonder what the simplest design would be like using a wallwart and controls? Wall wart can be wired in like a grid charger with the appropriate BMS.

 

I'm slightly conspiracy minded on this issue. I believe that Toyota wants us to make a service call to the dealer when our 12V battery goes dead.

 

I don't think I follow, but it seems like it would require a very simple controller. When you go to start the car, and the 12V battery has fallen below a certain voltage, the car will not go into READY mode, and requires either a boost or a dealer service call.

What I believe should happen, is when you press the start button, the controller would read the charge level of both the 12V battery and the hybrid battery, and determine whether it's safe to activate the DC to DC converter, thus providing a boost to the 12V battery. The controller must also guard against draining the hybrid battery below the lower threshold of charge, and should prevent allowing the boost if there is excessive drain on the hybrid battery.

This would save a lot of owners the anxiety of a dead battery not being able to start the car.

 

I feel the same. Regarding the issue from the original post, I'm thinking like most cost effective if you already have some de-oxit around is to just clean the corroded (in my situation) fusible link fuse wires, re-tin with solder and then calculate what size wire needs to be soldered in the gap to recreate the specified fuse rating value.

I have found with HV batteries, there are some instances where the modules are all still suitable or good enough and only the sense wire connection, HV computer connection or wires needed similar cleaning and potential re-tinning.

One other situation with the gen 2's are the ABS Actuator Accumulators going bad due to unaware or potentially worse rear drum brake assembly and or adjustment. Basically, the strut isn't out enough to the point where the emergency brakes don't engage on one or both sides. Always the situation when I've found the ABS VSC Traction codes, with the rare exception adjusting didn't remedy and the ABS pump sounded horrible or at least noticeably different lets say. Might also be brake fluid needs changed and or bled correctly.

 

The automatic car start system coupled with theft protection can perform these functions.
The automatic start algorithm in the cold season upon reaching the coolant temperature to the specified values can act exactly the same in relation to the voltage of the 12 battery.

 

Interesting you mentioned as I need to read into a SKS related code thrown that I'm not certain is from the HV Battery being bad or not. Furthermore, the two key fobs that can start the car do not have Smartkey or Door Lock-Unlocking functions. Bummer as I am thinking I'll need to see what is still in the yard with all the ECU's for the key fobs I have from and if swapping those ECU's with is more cost effective than having someone reprogram a master key with all the Smartkey functions. Anyone know if the Autel MAXIAP200 will? I don't want to brick my car and have to pay someone reprogram.

I still need to swap the Fusible Link as I'm paranoid the wire I soldered in isn't close enough spec.

 

Not only a key fob, but also a telephone can be used as a key for the autostart and alarm system.