2010 prius base Model Won't turn on at all

I'll start by stating I'm a very praticed backyard mechanic with much knowledge and tools.

I bought this 2010 that had a salvage title that was wrecked in the front end... primarily

the drivers side. They did a fairly good rebuild and paid less than 50% of NADA.

The car has appox 100K miles on it. It suffers from excess oil useage but that's not why I'm here.

Recently I ran into a no start dead battery situation. The low power (12v) battery had only 6.7 V.

So I said no problem bad battery. But that wasn't it. there was something running underneath the

hood drawing down the battery (stuck relay?). When the relay would let loose the car would jump to

12.8V and would start and run fine. This is an intermittent problem. Only happens sometimes. The relay

would stick and it maybe 10 seconds or it maybe 10 minutes or 10 hours. I am unable to get it into

stuck mode for diagnosis so it's very hard to diagnose and trouble shoot. While dead I have pulled

all the relays under the hood (fuse box) as well as the integrated relay and checked for burned or

bent connectors. checked the PCM connectors. All seem fine. Now that I'm writing this I didn't

check to see if disconnecting the integrated relay would break the stuck relay issue. I guess I

should try that the next time it stick. (DUH)

Symptoms:The horn was a problem prior to this no start issue coming up.

The horn was not working. Replaced the clock spring and checked out all wiring. When

the horn is connected it chirps like a machine gun on steroids (bad relay?) I searched and searched for

the horn relay and apparently it's built into an "integrated relay" in the fuse box under the hood.

I have attempted to trouble shoot that relay by going from ground to the 2 service pins where I

should be receiving 3.5 - 5v but it doesn't say with the car running or not running.

< I attempted to put a link to service info here but the forum won't permit it>

< for those in the know its on page 9029 of 2010 prius work shop manual >

< Prius L4-1.8L (2ZR-FXE) Hybrid (2010) >


The best I have been able to pull from those 2 points is 2.2V. So I am suspecting that the no start

and horn are related. And it stems from this relay. It's a couple hundred dollar part and I hate to

be a parts changer.

I have boot leg toyota service computer but I'm not to swift in using it.

Can a toyota tech help walk me through this issue. I know if I take it to my dealer they are going to

stiff me because of the salvage title... blah blah blah.

Thanx in advance,

-=Fred=-

 

No time to hookup the techstream this morning but ran a simple OBD2 "NO CODES"

The car was completely dead, had to hook up a battery charger for it to turn on and run

the OBD2.

Once again you could hear something running. And that was before I hooked up the battery charger.

Sounds like a pump or a fan of some sort.

 

yes Thank you

 

I own an 06 07 and a 2010 and am familiar with the noises.

Really would like to find out how to trouble shoot without changing parts. I pulled the obvious relays to no avail.

 

Thanks Bisco , can you elaborate?

 

Not to sound like a dummy... where would I start in the tree.

 

hooked up techstream tonight and did a health check and it's saying I have a difinitive issue with abs/vsc/trc and it says the pump relay is malfunctioning throwing DTC C1253

Yet when I goto the 7000 page 2010 repair manual it says the DTC c1253 is a pump motor

relay malfunction which would make sense and why I hear a pump running.

Question: does anyone know where this relay is located exactly?

There is a long drawn out procedure in the manual but thought perhaps someone could

short cut me to the issue.

As always Thanx in advance

-=Fred=-