2005 prius gas engine wont start

Thanks for the feedback.
I am not sure what you mean "Does the car become ready when I power Up". What are we looking for?

When i push the power button, the lights come on, but it does not start. I guess is that it is not ready when I power up. Something is keeping it from starting.

Bob

 

No trick, assuming that you have properly installed the traction battery interlock by pivoting the lever 90 degrees, then sliding the lever down to lock it in place.

The question about the car being ready is asking whether you see the READY light appear in the combination meter display. If you do not, then the car is not ready.

I suggest that you obtain Mini VCI so that you can retrieve the fault codes logged by your car's ECUs, which will give you a clue about what may be wrong with your car besides a traction battery module.

 

Check if you have power at relay smr1 in battery compartment next to ecu. You should have full voltage on one side of relay smr1 200 + volts DC

 

The 15A EFI fuse feeds the engine ECU through the EFI M relay. It feeds the fuel pump through the C/OPN (circuit opening) relay. It also provides power to the mass air flow sensor, the air/fuel ratio sensor heater, and the downstream oxygen sensor heater.

What makes troubleshooting difficult here is that both relays are part of the integration relays. EFI M is part of the Unit B integration relay while the C/OPN relay is part of the Unit C integration relay.

I suggest you buy several 15A fuses for use during troubleshooting. Then, pull Unit C integration relay and see if the 15A EFI fuse will blow when that relay assembly is absent.

If it does not blow, then try disconnecting the fuel pump and then reinstall Unit C integration relay. See if the fuse blows. If the fuse does not blow, then the problem is downstream from wherever you disconnected the fuel pump, perhaps the fuel pump motor is shorted for example. In that case you would have to replace the entire fuel tank.

If the fuel pump is not the issue, then there may be a problem with the wiring to the MAF sensor, a sensor heater, or one of those parts may be shorted.

You could try disconnecting all of those parts, and see if the 15A EFI fuse remains good. If it is good, then reconnect the parts one at a time, until the fuse blows. That last part to be connected would be the bad part. If the fuse blows even when all of the parts are disconnected then there is a wiring harness short somewhere.

Obviously your troubleshooting will be enhanced if you have the electrical wiring diagram for your car, which you can obtain at the subscription website techinfo.toyota.com

 

Thanks for the feedback. This is clear and helpful.

 

Thanks for the detailed feedback. I will order an electrical diagram as you suggest and continue the troubleshooting.
This was very helpful.

 

After several attempts, I am at a point where I will need some more specific help or I will need to purchase a replacement battery pack.
- I have not rebalanced the batteries, but 26 of the cells are between 7.4 and 7.6 and two cells 7.75 and 7.69 (28 total). This is a little out of family, but I do not have a diagram to set up the charging/balancing the voltages closer.
- I have measured 217 Vdc on the battery side when I have all of it put together in the car.
- Removing the positive and negative cables on the 12v battery should reset the system.
- I am still getting error lights when I attempt to start the car.

I am wonder what sets the fault modes. i.e. How does the start up test software work? Or is there a hard wired voltage value that sets the error indicators.
Does the Battery computer assembly typically fail?

Any additional feedback would be appreciated.

 

no, It does not become ready when I power up. I am still getting the lights in the dash.
I am assuming that there is a fault mode that is telling me that the batteries are not balanced.

After resetting the modes as well as disconnecting the battery to reset the system, I thoughts that the car would start up and then provide any errors then.

 

I am taking your advise and replacing the traction battery. I will let you know how that works out. Thanks again for your help. Greatly appreciated.

 

The heaters for the A/F ratio sensor and the O2 sensor are integral parts of each sensor.

 

If any of you need the Gen2 Prius Technical manual, send me a PM and I will reply with links to zip archives (there are two: 2004-2005 and 2006-2009) on my personal web server.

JeffD

 

The electrical wiring diagram is available at techinfo.toyota.com

 

just so you'll know, you might fail a smog inspection in CA from the aftermarket cat. It's not legal.