Prius won't start, flashes the combination meter for a split second

First thought is to see if the AM2 fuse in the underhood fusebox is blown. A common scenario is for the inverter coolant pump to fail and short - popping the fuse. That fuse also supplies power for the power source control ecu for most all "ignition on" circuits. Such as the combination meter (speedo) and ECM.

If that fuse is blown, you can unplug the coolant pump and replace the fuse. There's a single wire (white with black stripe) connector near the left front strut tower underhood. That will disable the pump.

The car should then run but keep the drive slow and not too long (no A/C) - otherwise the inverter will overheat and turn off. Then you would need to replace the pump- I only use a Toyota part as aftermarket parts have questionable reliability.

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put it on a lift to see if you hit something

 

I would scan all the ecu's on the car with a capable scantool and see which ones respond. That would give clues as to which systems are working.

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I have a similar (if not identical) problem. Any luck finding a solution?

 

My profile says I have a 2013 Prius v (I do), but I also have a 2002 Prius and this is the vehicle with the above problem. Not sure how to add a second vehicle to my profile...

But would love to fix the '04 that is experiencing the same prop that the OP is inquiring about.

 

ECU board? Or do you mean PCB?

 

That is the engine management computer (ECM).

Interesting that it should fail in the way you describe.

It is a shame you could not pull codes as that would have been interesting to see what they were, though not surprising with a failed ECM.

Glad you got it sorted and are on the road again with the 2004.

 

Thanks for the update! I was kind of thinking it might be one of the car's brains. Haha.

How did you conclude that this was the failing part? Was it visibly fried? I'm hoping to diagnose mine and repair. And did you swap it out yourself? Thanks again.
-Bob

 

Well, that wasn’t the problem. Or wasn’t it?

I bought a used ECU from eBay and put it in today. The car turns on for a split second and then back off, as described in the following linked post where I started a thread about my non-start prob: 2004 Prius won’t start up. Died while driving. Warning lights blink then shut off. | PriusChat

After reading this thread, I thought my ECU might be bad. Now that I've swapped it, either my ECU wasn’t the problem (and I, once again have no idea what the problem is) or the used ECU I bought is broken in the same way as mine.

It might seem unlikely that the used eBay ECU failed in the same way as the original but I did once buy a used ABS actuator for a Gen 1 Prius and put it in (huge pain in the rear) only to learn that it did not work at all and wouldn’t even power up. So, it happens… ugh.

If anyone has any ideas or suggestions, I’d appreciate it.

Thanks.

 

UPDATE:

I re-checked the AM2 fuse and it’s blown. Swapped the fuse and unplugged the inverter coolant pump and it started right up. Plugged the inverter coolant pump back in and started it up. Started smelling burny and smoke wafted up from the inverter coolant pump. Turned it off and ordered a new inverter coolant pump. Sounds like this was the problem all along. Ill update when I get the new inverter coolant pump in there.