2014 Prius Won't stay running

Its not running at all. Its cranking. They crank at about 1000rpm as opposed to 200-300 rpm of regular ice vehicles. Its needs a new hybrid battery.

Ok. The owner told me that they were able to drive around the block one time. Guess the battery wasn't taking any charge.

"Guess the battery wasn't taking any charge." Yup. The opposite in fact. The battery was cranking the engine and driving the MG2 to move the car. It's annoying when owners, then tow drivers, and then maybe a fellow employee who didn't know it was a no-start, all move the car and discharge the HV battery, leaving only one or two cranking attempts left for diagnosis. We have a charger, but…

Post the freeze frame data from the P3190 or P3191 and I’ll give you a hand. Rudy is right about the fact that it’s cranking, not running. You can recharge the battery, but you’ll need a charger to do it. Don’t keep on trying to start it. If you fix the issue that is causing the engine to not start, you can use the engine to recharge the battery, assuming you get one more try at it and haven’t…

I got p3000 code. They were trying to restart several time. I only tried 3 or 4 times to start. The owner said that they were successful once in staring and driving it around the block.

If you have a P3000 in the HV ECU without a code in the HV Battery ECU, that means the battery SOC% is low. P3000 is like a P0700. It just means there's a code in the HV Battery ECU normally. The only time it will set when there isn't a code in the HV battery ECU is when the SOC% is too low.

Check for any debris in the MAF.

That’s not an issue on the gen3. Only gen1 and 2. Otherwise a good guess. Better to look at the engine data rather than guess. It cranks in closed loop.

What do you mean “cranks in closed loop"?

During cranking the air/fuel sensor will display real mixture data. If it's 3.3V or close, you know that the mixture is 14.7:1 and fuel isn't an issue, leaving only spark, timing, and engine mechanical. If the AFS is lower than 3.3V, then the mixture is rich. If the AFS is higher than 3.3, the mixture is lean. It's common to see Prius no-starts with and AFS reading of 4.9V (full lean). If the…

Wow I had no idea that hybrids, at least Toyotas, used closed loop strategy even when cold while cranking? So what happens when it starts? Doe it revert to an OL strategy for cat. light off? I need research that. Thanks for the info.

Paul is it normal for the catalyst temperature Pids to both show -40deg?

There is no sensor. It's a calculated PID. Honestly, I don't know. I've never used that PID for diagnosis of any sort.

Thank you Paul for all the knowledge you dropped. I really appreciate it.

Hello Lesage, Does it have a safety disconnect for the high voltage system? I have seen them disconnected before and forgotten about. Be extra careful working around these high voltage DC systems if you test anything Don't trust a 0% state of charge message.

Hello Glen. Thanks for the advice, I'll be careful. It has the safety disconnect for the hybrid battery. I'm trying to find out from the owner, when they drove it off the truck and around the block, if it ran on battery only or ICE only. I'm still leaning towards a bad battery.

A problem with the service plug will set a P0A0D. Certainly common to finds them only partially installed though. And yes, even at 0% SOC, the battery still packs a wallop.

Vehicle is having ICE turned by transmission. They drove around the block on battery power depleting the battery. You didn’t list mileage but these are famous for blowing head gaskets. The hybrid battery comes up a little after sitting and is allowing you to attempt another start of the ICE. If you get the ICE running it will recharge the battery. Look for coolant in the number one cylinder…

Mileage is 149K. Early on I suspected a lying gas gauge. But I verified the level, sort of, by pulling the pump out. I manually confirmed that the pump runs with a PP. The maf looks good and circuits react when unplugged. I'll verify the fuel pump circuit and number 1 cylinder. Thanks

I had a similar instance where a stuck open EGR valve caused the no start. Do not believe the PID on the scan tool. Remove the EGR and make sure it is not wide open.

Thank you sir. I'll check that on Tuesday.

Your old battery was beyond discharged. Your new to you battery is also low. Static voltage is usually around 230. You really need a scanner. Techstream, Autel, or something. That’s how to diagnose these. Measuring battery voltage and manual testing won’t do.

i have an autel 906bt. SOC is at 29% at the moment. What pids should be useful to me?

Uh oh. 29% is low, but the engine should crank. There’s no ”rule” (that I know of), but they’ll usually crank up until the very low 20s. I’d guess head gasket and hydro lock. Maybe try cranking by hand and removing the plugs. You could look at the battery current while cranking, but you’d be better off with manual testing because you likely only have 5-10 cranks left. Toyota says…

If every cell should measure 7.2 volts and there are 28 of them, how does the static voltage get to 230 volts? Can these cell go to 8.2 volts?

7.2 V is based on 1.2 V per cell. A nickel metal hydride battery fully charged is about 1 .5 V per cell. 1.5 V times 6×28 is 250 something. Toyota typically tries to keep the SOC between 40-60%. Around 15.5v per block (12 cells) is typical, but obviously it’ll go up and down. Sorry. On my phone. Typing is slow. Edit now that I have a keyboard. Here are a few examples from live data and FFD…

I forgot to say that you can crank the engine by hand. Clockwise only or the timing chain may jump.

Sure sounds like coolant in the cylinders. I have seen high mileage vehicles driven on battery only once there was engine failure until battery was depleted and not recover enough to restart once the engine was repaired/replaced. Old school - why not pull the wiper basket and plugs and crank to see. There are several methods from home made chargers to disassembling the battery and charging the…

Hello Steven, What jdm engine vendors do you recommend? Some people mentioned using the 4th gen short block, but I'm afraid rebuilding the head will make it less cost effective.

Hello Lesage, You probably already know this, but I will mention to make sure you do not overlook what led to this catastrophic failure. This likely will need a radiator among other surrounding items. This is the risk people take with auction vehicles.

Hello Glen, I will surely check. Although based on what's been said in this thread, it seems that it's more of a design issue with this engine and the HG just leaks. Will check WP and rad.