Help diagnose - won't start

Okay, I charged up all those individual modules. True, there are definitely 3 of them that are dead and won't take a charge, but the rest of them charged up okay. and guess what? I put the battery in the car, turn the key, and you can hear what sounds like the engine running. Only, it is just the HV system turning the engine. It only does this for about 3 seconds and stops. Unfortunately, I don't have a toyota scan-tool but I do have a generic one and there are no engine codes. Here is what is going on, the spark plugs are sparking.. I checked this with a spark-test. However, the fuel-injectors are not firing, ever. I confirmed this with a noid-light and a voltmeter.

I was able repeat this by pulling the 12V battery cable, waiting a few seconds, and trying to start the car again. Each time, same result. In fact, I did this about 20 times before the HV battery became so low I could audibly hear the engine was turning over much slower, and eventually got to the point it wouldn't turn over at all.

I have a working theory, but it would be great if somebody could confirm it. According to my friend who was helping me, the Prius is supposed to get the engine up to 1,200 RPM to start. He also says the computer is normally supposed to try starting the engine for 8 seconds before giving up. Is it possible that the battery level wasn't good enough to achieve the proper RPM to start feeding fuel? And that after 2 to 3 seconds it realizes the battery is not working and just decides to stop trying to start? Obviously the battery is in dire-straights being that 60-seconds (total) of cranking the engine totally drained it.

 

Well, since it is giving a spark, I figure it knows the crank position. (I could be wrong?)

Although I didn't check the fuel pressure, I wouldn't have thought that would stop the computer from trying to power the fuel injectors.

Nothing, they are still in there.

 

Haha. That was the first thing I did when I got it home, upon advice from a friend.

 

Yeah. that seems to be the problem. And the ironic thing is my best friend is a Toyota master technician and an expert on the Prius. The problem is I don't have a toyota scan-tool and he is not allowed to take them from his workplace. He can't really diagnose any further without knowing the codes from the hybrid computer. So the only way to get that would be to tow the car to a dealership, then pay them to scan it. Well, I think before I did that I might as well just buy my own scan-tool if I can find one at a good price.

 

No problem. here we go:

I saw this car advertised on craigslist in my area very cheaply. The guy told me he bought it from an auction a few weeks earlier and drove it around and noticed it was having problems where the engine would rev up, the car would drive very slowly, and the HV battery warning light would come on. He said it took it to a toyota shop and they diagnosed it as a bad battery.

He had already removed the battery pack and measured the voltage on each module. He assumed 3 were bad so he bought 3 from ebay. However, the ones he bought were also bad. He didn't want to mess with it anymore so he decided to sell it.

I eventually worked him down to $2,800 and bought the car. I had the car towed to my house with all of the parts just crammed in the back. area, including the seats, tons of bolts, and the battery pack.

So that first day, my toyota friend came over and we re-assembled the battery and put it in the car. We could never get the car to do much of anything except display the warnings on the screen. It would never turn the engine at all, or enter READY mode.

So we took the battery back out. I went down and bought a fancy R/C car charger and started charging each module. I could tell which 3 modules were replaced by the previous owner because they were slightly different color, and buldging on the sides a little. Most of the modules took a charge and held it, but these 3 would be showing 2 to 3 volts after just an hour or two after charging.

I bought another battery pack from a local guy for $50 but discovered that all of the cells were reading 0.00 volts and none of them would hold a charge at all. So that was a waste.

I also cleaned all of the corrosion and in the process found a sense-wire that was broken off from corrosion and the electrolyte had wicked about a foot down the wire. I replaced the entire wire and put a generic terminal on the end of the new wire. It seemed to fit okay. I also found the 12V battery was reading about 9 volts, so I charged it up.

Still, we decided to see if the car would start with the 3 bad modules. We put the battery in the car and tried to start it. The engine ran for several seconds and died with a knocking sound. My friend says the knocking sound is good because that means the engine still has good compression. Anyway, I plugged in my generic scan tool and found that there was a code. I don't remember the number but I looked it up and found that it was a "BATTERY ECU COMMUNICATIONS" error. After a quick look, I realized I had not plugged in the battery computer's data-link cable. (I'm surprised it tried to start!) Anyway, plugged that in and cleared the code. Unfortunately, same problem. The engine spins for about 2 to 3 seconds and stops. Then it will not allow us to try starting again until we disconnect the 12V battery cable for a few seconds.

So, at this point, my friend asked me to put my hand behind the tailpipe and see if the air coming out was hot or cold. it was cold, so he said there was no combustion going on, just the I.C.E. being spun by MG1. So we checked for spark on one of the plugs, and found that it was indeed sparking. he said this means the crank-sensor must be working as well as the engine computer. (also because I could pull codes from the computer) So next we tested the fuel-injectors. This is where we found nothing. No voltage coming from the fuel injectors. We checked with a volt-meter and noid light.

We continued to try starting the engine but each time we could hear it running slower and slower. Eventually it wouldn't go at all.

And that's pretty much where I am. My friend says he doesn't know how to diagnose it further without the computer codes.

I'm guessing my first mission should be to solve the battery problem. Then I guess if it still won't start, the next thing would be to buy a scan-tool.

 

I'm not sure which brand it is, but I just bought a scan-tool from the guy at the Re-Involt place in NC. I was talking with him about the refurbished batteries and mentioned the issue with a scantool. He said they buy this one for around $200 that does everything on the Prius. He said he could sell me one for $215, so I gave him my credit card and he is shipping it to me. So I should be able to diagnose this further.

I'm also re-considering the refurbished battery pack because he said shipping is $100 to Ft. Worth (I figured it would be more than that)