Prius dies after changing spark plugs

Where did you get the spark plugs? ebay and amazon are known for counterfeit items (like plugs). I think that your car is only trying to start but never running. The prius spins the engine at 1000 rpm when it wants to start- if it doesn't run it will stop after 8-10 seconds (sounds like a start and stall but is really never started at all).

A possibility for your problem is that something is wrong with a coil- each coil should send a signal to the ECM that it produced a spark when commanded. If any coil is faulty or not plugged in and doesn't send the signal, then the ECM can disable the engine. BUT that's a guess.

You really need to have any and all codes read from (all) ecu's in the car. (and don't attempt to start the car more than a couple times unless you find and correct a fault. Each start attempt uses power from the HV battery- don't want to run that down too far).

 

Coils, plugs and cables. Did you crack a cable?

 

What cables do you have in mind?

 

What spark plugs did you install? Brand, model and source?
Did you reconnect the wire harness to the coils?
Did you disconnect the 12v battery prior to performing this job? If so it may be possible you're running into a problem due to ECU going back to default values.

 

Spark plug wires

 

Aren't any

 

Is to there a harness?

 

The coils have 12 V supply connections, just like in any other car. Nothing replaceable (without replacing or rebuilding the whole engine wire harness).

Because the coils sit right on top of the plugs, there are no "spark plug wires" like what you might replace in other cars.

 

Thanks for the explanation. Your experience is always welcome.

 

Because of one rodent ….
Wire harness replacement | PriusChat

 

ECU default issue. Sometimes happens. Not frequently, but often enough that I've experienced it a few times. When you drive your car, there are some parameters the ecu learns ands adjusts while driving. These change over the course of miles and years. Things like throttle body position due to carbon buildup. It may not seem like much, but when the 12v system is turned off, and the ecu goes back to default, the learned value is gone and is now the "as new" value. If different enough from the learned value, the car may not start. I've been able to resolve this each time by thoroughly scrubbing the interior of the throttle body to remove the carbon deposits, allowing the throttle plate to return to it's 'as new' position, which now matches the 'as new' default value. It's also a good time to remove and clean your mass air flow sensor, especially since removing it gives you much better access for scrubbing the inside of the TB. I remove the air cleaner assembly, remove the MAF sensor (unplug it, then remove the screws just using finger power and a phillips screw driver tip), scrub the TB with a small toothbrush and TB cleaner, while holding plate open with a tool. On the MAF, clean the exposed temperature bulb (you'll likely be amazed at the difference) and the element that is buried inside the housing using MAF cleaner. The element inside the housing is delicate, but I've gently used a cotton swab to brush it after spraying and was surprised at how much additional stuff came off. I had to do the cotton swap thing because after cleaning the first time only with spray, I continued to get random lean codes. problem solved after the cotton swab.
Don't forget to plug the MAF harness back in after you're done. I also ALWAYS disconnect the 12v battery before I work on/disconnect any sensors.

This little default issue is one reason why I stopped disconnecting the 12v battery when replacing an HV battery. Hate it when someone freaks when their car wont start/run and codes out after a HV battery replacement. Then I end up spending 15 minutes explaining, and more time disassembling and cleaning. Easier to just leave it connected....and a good reason to use a 'saver system' when replacing a 12v battery.

 

So have you cleaned the MAF sensor, throttle body and throttle plate as advised by TMR-JWAP in post #14? If you haven't that should really be your next priority.

What is the voltage reading of your hybrid vehicle (HV) battery, out of interest?

BTW, not that it is likely anything to do with your current problem but as a general 12 V battery housekeeping issue,11.8 V for a new 12 V battery is pretty poor. Get that charged up using an external smart battery charger if you care at all about the longevity of it. Is it an AGM battery or a standard flooded one?

 

What app are you using with your OBD bluetooth adapter? Does the dash - speedo light up (and all the warning light test) when you try to ready up? If it does but no ready then there has to be a code somewhere. Dr Prius app might help for hybrid control (and HV battery codes- maybe).

There's a sticky at the top of the Gen2 Technical forum about apps- short form is the Autel Maxi AP200 is pretty much the best device and app for diagnostics.

You have to go to Techstream or a similar level professional scanner to have more functionality.

Posted via the PriusChat mobile app.

 

Dr Prius even free version will get you HV battery parameters
Look on their website for the guidance on dongle that is compatible. Should be about $25 on Amazon