P0A9B Hybrid Battery Temperature Sensor Cicuit

I replaced 1 module/blade in early 2018 and another 2 in early 2020. They only triggered the Red Triangle of Death and the hybrid battery cooling fan. The car otherwise acted and drove normally. And the bad modules were identified only by their lower voltage using a $5 VoM.

Now I have the R.T.o.D., battery cooling fan, strange "!" (brake?) warning dash light, Engine (symbol) Check dash light, Maint. Req'd. dash light, wild swings in the displayed hybrid battery charge level, and the engine occasionally jumping to its max RPMs until I turn the car off and back on again. I've been clearing codes with the cheapest ODB reader Walmart sells, which typically reports "0 DTCs," despite the Xmas tree dash board.

I now have a 4-channel 100W charger, in order to recondition and balance the modules for the first time.

The "shiny new pack from Toyota" suggestion either ignores the $1,950 + 10% tax cost or comes from someone who can get one at/below cost. I'll be happy to take a shiny new one at, say, $600.

 

Not going to happen.

 

If I can get an Eras Tour ticket in Indianapolis for $30 I'll go.

 

You can get a decent scantool app and device for your smartphone, here's a review thread. Some of the options can scan all systems on a Gen2 Prius for codes, data, INF codes and more. Many here also get a "specialized" app like Dr Prius solely to monitor HV battery block voltages.

I went the "DIY battery refurb" route when I first got my 2006. Once was enough. I had 4 chargers then also got a dedicated discharger as the other units only did 5 or 10 watts discharge. Took about 5 weeks total to do 4-6 cycles per module (about 5-6 hours per cycle) times 32 modules total (27 original plus 5 replacements for modules that tested bad).

The resulting pack worked "ok" for 2-1/2 years and 50k miles. When it started to give problems I got a new OE pack immediately. (Was saving up for it).

It's a good chunk of change, but so worth it.

Posted via the PriusChat mobile app.