C0000 DTC today. red triangle abs check engine and (!)

hello all.

i guess it had to happen...

i got my first ever DTC today.... c000 looked it up and it's Toyota Vehicle Speed Information Circuit Malfunction.

it happened as i was slowing down from 70kmh in B mode for a stop light.
i felt a small "clunk" and then the beeping and red triangle check engine light VSC ABS and the (!) were all showing. i was at he head of the lights, so when they went green i tried pulling away and had no power. engine was running and revving a little, but there was no drive.

i think the clunk was the HSD releasing maybe ?
it didn't feel like i hit something, or metal on metal kinda noise. just a dull thud.

luckily it was downhill and i could pull off the main road onto a side street.
i stopped the car, powered down and then turned back on. all warning lights were still on.

then i remembered that the SG2 can read and clear codes !
i checked the code (only 1 was present) this was the c0000 vehicle speed circuit malfunction.

i figured since it wasn't a HV drive code, i could probably reset the code and see if it returned.
so i cleared the code and the car returned to normal. i then drove the remaining 5km home with no problems.

seems strange that a vehicle speed sensor malfunction would cause no drive ?

anyone have any experience with this code ?

thanks in advance.

Jason

 

thanks for the info.

the code came from the SG2 screen. i looked up that code using google, and thats where i got the info from for vehicle speed information circuit malfunction.

Generic OBD-II C Chassis Trouble Codes

its at the top of the list. its not a Toyota specific code.
its a generic OBD2 code so it's probably the same for all cars that use OBD2.

once cleared, i drove home without a re occurrence.
i will be driving the car today and will see if it happens again.

if it does return, then i will have to investigate further.
though with my skill level (or lack of it) i will likely have to take it to a dealer to sort out.

Jason.

 

i use B mode when slowing down for lights or on long descents to Maximize regen.
B mode doesn't limit regen. it maximizes it. the Prius will only engine brake when the HV battery is full.

i don't drive in that mode all the time.

the C0000 is not a Toyota specific code. its a generic OBD2 code (the Toyota Prius is fully OBD2 compliant)
so while it is possible the SG2 didn't read the code correctly, it is also quite possible that it did.

drove for about an hour today, no code returned.

im wondering if the fact that the car lost speed information, it may have shut of the HSD to protect the motors,
as we all know they are protected by the engine running (turning over anyway) above a given speed.
without that speed information, it might have shut the HSD off to avoid any potential damage ?

im only guessing here, but i think maybe the P codes are power-train and C codes are chassis codes ?
so it's possible i may have a failing ABS speed sensor that triggered the code ?
i will keep watching it and see if it returns.

Jason.

 

i wonder why then do i see a BIG increase in regen current when in B mode vs not in B mode ?

typical regen under coasting is 30A maximum. usually around 25A.
while in B mode i often see 40-50A.

and i have seen as high as 92A under brake pedal applications.

i agree that B mode will engine brake if the HV battery is full though.

Jason

 

also, according to this site...

Trouble-Codes

i was right.
C codes are generic chassis codes. not manufacturer specific.

P codes are power train codes and would include the prius specific ones.

Jason.

 

often in B mode i would still see 0RPM on the SG2.
and most of the time (above 46kmh), i would see 900RPM

im still only relatively new to the Prius, but so i guess it COULD be showing wasted energy, but that doesnt seem to fit in with how quickly i see the HV battery volts and SOC rise under B mode.

as i said, i don't drive in B mode most of the time.
when i first got the car, i did, and then a read the manual

in the manual where it recommends not to use B mode all the time, it says that it COULD lead to increased fuel consumption. i took this to mean that due to you having to accelerate to the stop light if the car slowed TOO much...
that COULD lead to increased fuel use.

so now i only use it for descents and long coasting stops for red lights etc.

now to get to the bottom of this DTC....
yes it's not a Toyota specific or even Prius specific code.

but it is a valid chassis code (including the ABS system)
so my best guess at the moment is that it is a faulty ABS or wheel speed sensor,
and without valid speed data, the HSD shuts off to avoid potential damage due to over speed on the motors.

jason.

 

i stand corrected with relation to B mode.

the engine does indeed turn over in B mode, but no fuel is injected and i do see more regen in B mode than not.

as for the other code issue, ill have to wait until it shows its head again.

Jason

 

I think I'm somewhat closer to confirming that this is an abs sensor problem.

The DTC that showed up the other day has not yet re occurred, BUT I have seen the Traction light flicker a few times in normal driving.

Not on the brakes or hard acceleration. It's definitely not a situation that would call for traction limiting or abs intervention.

So it looks (to me anyway) as if one or more of the speed sensors is intermittently faulty.

Will have to get it diagnosed properly.
I will take the car to the mechanic and get him to run a full diagnostic sweep and a visual inspection of the abs sensor area.

I will report any findings here.

Jason.

 

Interesting. The road was a little bumpy. Nothing over the top though.

All 4 tyres match and have good tread depth remaining. I have Michelin LRR tyres on it. Can't remember the exact type though. They were replaced by the previous owner just before I bought the car.

In the 2 months or so I have owned the car, I have only seen the traction / vsc light flicker 2-3 times.

It's possible I just haven't noticed it before though.

I guess more investigation will be required.

Thanks for the info.

Jason.