Diagnostic codes: Is my hybrid battery failing?

So over the past couple of weeks my check engine light has gone on & off a few times. The first time it was on for a few days; subsequent times usually just a few hours.

Took it to a shop (not hybrid specialists & I've only been there a few times but they have good reputation) they ran the codes and got : P1121 Coolant Flow Control Valve Position Sensor Circuit Stack. C2318 Low Voltage Error (Power Supply Malfunction), P0A0F Engine Failed To Start, B2799 Engine Immobilizer System.

The shop replaced the water pump (they saw that it was seeping, and there was low coolant in the reservoir). The light came back on 2 days later, I talked to the shop and they said likely the hybrid battery starting to fail.

Thought I'd run this buy you knowledgeable folks before starting to get super worked up (I am thinking of taking it to one of the few local hybrid specialty places - I prefer independent shops - to get the battery tested but perhaps someone has a better idea for how I can do some DIY testing without going to a shop? TIA!

 

no it was just their guess I think based on the age/mileage and the fact that check engine light is going on/off intermittently and fairly frequently (every couple of days). I did a little research and discovered that the low voltage code corresponds to the 12V and not the hybrid battery. Having a harder time determining specifics on the other codes.

 

thanks, I'm beginning to think the same. There are a few shops around here that have hybrid certified mechanics, would they have the right equipment to diagnose? My experiences with going to car dealerships for work here in Seattle haven't been great so I tend to avoid. She has just under 102K miles.

Very good to hear that check engine light is NOT indication of hybrid battery trouble. I've seen a number of posts on this forum about expected lifespan of180K (and the battery lasting that) which would be nice

 

Thanks, good to know. It was originally a California car (Bay Area/Marin) its previous owner drove it up here to Seattle & I bought it just over two years ago.

 

sorry I'm not mechanically knowledgeable. 3-way valve?

 

ok looked it up, you mean the coolant valve. The shop did look at this but didn't replace it, here's what the shop wrote:"Had technician turn on vehicle while this tech felt control valve for flow. Coolant feels like it is flowing, but difficult to tell if all 3 passages on valve are working properly. Recommend replacing water pump as starting point. " [note they had determined that water pump was leaking]

my next stop is one of a couple local places that are hybrid specialists, Greentec Auto or Northwest Automotive (likely the latter, the former would be very inconvenient as far as location)

 

I'm also about to engage in (what I am sure will be) a fight with the dealer that sold me the car (Ford dealership) since they did front pads/rotors before I bought the car but I've since discovered they were done wrong (at least one place has said the rotors clearly WEREN"T done, plus the brake hardware is missing which it looks like may be causing premature failure of brakes due to uneven wear). And I had been so happy with how low-maintenance this car has been (esp compared to my previous car, a 1999 Passat)

 

Seattle. West Seattle specifically, I work at the UW.

 

LOL I do like a good road trip but don't have the time. Appreciate the offer. My understanding is that same code can be due to a low coolant level (it was low, with nothing in the overflow tank)? Mind you I had all fluid levels checked at my last oil change on June 15th.

So nobody competent up here (other than dealership)?!

 

Ok thanks appreciate any info you come up with. There *have* to be places here, Prius is probably the 2nd most common car (after Subaru).