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Old 03-02-2014, 03:57 PM   #1
tylerwatts53
 
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07 cranks, won't start--no fuel?...

Hi folks,

I'm hoping to tap into the collective wisdom here. I have an 07 Yaris that I bought new. We've put 170,000 miles on it so far and it has been trouble-free except for routine maintenance (oil/filters, tires, plugs @ 120K mi, etc.).

Friday we all got in (wife/kids and I usually carpool) and it started as usual, but then sputtered and died not a block out of the driveway.

Engine cranks strong--I replaced the battery less than a year ago. I also checked for spark at the plugs with a spark plug tester-- I have spark. So it must be fuel. I thought I might have just run it out of fuel, even though the fuel gauge is showing 2 bars, so I put 5 gallons in. Still nothing--cranks hard, but not firing. I should also note here that it is STILL SHOWING ONLY 2 BARS on the fuel gauge (it should be at least half full!).

To verify that it is a fuel problem, I shot some starting fluid in the throttle body intake--turn the key and, sure enough, it fires right up and will run for a few seconds on the ether.

I have since pulled the fuel pump and bench tested it by hooking up directly to a 6A 12V source; pump whirred to life and the remaining fuel in the sump began squirting out the outlet, so it looks like I'm OK there. Also, I hooked up an Ohmeter to the leads for the float, and it shows smoothly varying resistance through its range of travel (from about 80 with float at lowest level down to 0-10 at highest).

So this must be electrical, right? I have checked and re-checked the fuses (in the engine compartment panel) and can't find ANY that are blown? So is it a relay? Is there one that controls the fuel pump/ sending unit? Any thoughts at all on where I should be looking next will be greatly appreciated? (I would love to get this car up and running without dropping any $$ at the dealership!)

Oh, and one more thing I should note: hooked up an OBD code scanner and no codes are showing up (check engine light NOT on when ignition in on position).
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Old 03-02-2014, 05:07 PM   #2
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Quote:
Originally Posted by tylerwatts53 View Post
Hi folks,

I'm hoping to tap into the collective wisdom here. I have an 07 Yaris that I bought new. We've put 170,000 miles on it so far and it has been trouble-free except for routine maintenance (oil/filters, tires, plugs @ 120K mi, etc.).

Friday we all got in (wife/kids and I usually carpool) and it started as usual, but then sputtered and died not a block out of the driveway.

Engine cranks strong--I replaced the battery less than a year ago. I also checked for spark at the plugs with a spark plug tester-- I have spark. So it must be fuel. I thought I might have just run it out of fuel, even though the fuel gauge is showing 2 bars, so I put 5 gallons in. Still nothing--cranks hard, but not firing. I should also note here that it is STILL SHOWING ONLY 2 BARS on the fuel gauge (it should be at least half full!).

To verify that it is a fuel problem, I shot some starting fluid in the throttle body intake--turn the key and, sure enough, it fires right up and will run for a few seconds on the ether.

I have since pulled the fuel pump and bench tested it by hooking up directly to a 6A 12V source; pump whirred to life and the remaining fuel in the sump began squirting out the outlet, so it looks like I'm OK there. Also, I hooked up an Ohmeter to the leads for the float, and it shows smoothly varying resistance through its range of travel (from about 80 with float at lowest level down to 0-10 at highest).

So this must be electrical, right? I have checked and re-checked the fuses (in the engine compartment panel) and can't find ANY that are blown? So is it a relay? Is there one that controls the fuel pump/ sending unit? Any thoughts at all on where I should be looking next will be greatly appreciated? (I would love to get this car up and running without dropping any $$ at the dealership!)

Oh, and one more thing I should note: hooked up an OBD code scanner and no codes are showing up (check engine light NOT on when ignition in on position).

It sounds like the relay that controls the fuel pump is not firing. Did you verify that the fuel pump is not receiving power when you turn the ignition on?
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Old 03-02-2014, 05:09 PM   #3
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By the way, check out this thread for more info. The fuel pump relay is integrated into the body ECU, which is the under-dash fuse panel / junction box:

http://www.yarisworld.com/forums/showthread.php?t=45663
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Old 03-02-2014, 05:14 PM   #4
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Cold in Indiana? Ice in fuel line? Happened to me once many, many years ago.
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Old 03-02-2014, 05:37 PM   #5
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Quote:
It sounds like the relay that controls the fuel pump is not firing. Did you verify that the fuel pump is not receiving power when you turn the ignition on?
Yes, insofar as I turned the key to ON and listened to see if I could hear the fuel pump turn on (and it did not).

Quote:
Cold in Indiana? Ice in fuel line? Happened to me once many, many years ago.
Thought about that-- I did put some Heet in the gas on 2-28, and the temp. was above freezing on 3-1 while I was starting it on starting fluid.

So, if it is the fuel pump relay in the body ECU, does that mean I need to replace the body ECU? Any thoughts on how difficult/ expensive a task that is?

Thanks guys for your speedy replies!
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Old 03-02-2014, 05:47 PM   #6
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Originally Posted by tylerwatts53 View Post
Yes, insofar as I turned the key to ON and listened to see if I could hear the fuel pump turn on (and it did not).



Thought about that-- I did put some Heet in the gas on 2-28, and the temp. was above freezing on 3-1 while I was starting it on starting fluid.

So, if it is the fuel pump relay in the body ECU, does that mean I need to replace the body ECU? Any thoughts on how difficult/ expensive a task that is?

Thanks guys for your speedy replies!
With the heavy addition of alcohol to Winter gas these days, ice in the fuel lines has become a rare occurrence.

If it is indeed the bad relay, replacing the body ECU is a bit of a hassle because of all of the connections to it and the fact that you really need to remove the dash top to get to it properly. A replacement is over $600 from Toyota, but used ones are much more reasonable. I have 3 or 4 on hand, but you would need to verify the part number on the sticker on the back of yours or shoot me your VIN via PM and I can tell you which one your car needs.
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Old 03-02-2014, 06:38 PM   #7
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Scott,

I read through the thread you linked to and started doing the checks you indicated:
Quote:
The EFI relay is in the integration relay. It's coil is connected to pins 2 and 3 of connector 1A. If you measure the resistance between those two pins you should a resistance under 100 ohms.
174 ohms

Quote:
If that looks fine, you can fire the relay using a 9 volt battery and two pieces of wire. Connect one terminal of the battery to pin 2 and the other to pins 3 and you should hear the relay click closed.
Went ahead and tried this--nothing.

Quote:
The C/OPN relay is actually not within the integration relay, but rather is in the body ECU assembly (within the guts of the under dash fuse panel).

The coil of the c/opn relay is connected to pins 4B-9 (red wire) and 4E-5 (violet wire). With the ignition off, if you measure the resistance between those two pins you should measure under 100 ohms.
163 ohms.

Quote:
The contacts are connected to pins 4A-8 (black wire) and 4B-11 (black wire). With the ignition in the ON postion, measure the voltage on the pin 4A-8 and you should see 12-14V, if the relay is closing properly.
Should I be taking voltage across these 2 pins, or from 4A-8 to ground? I tried both, and it came up 0 both ways (with the key on).

BTW, to verify my ohmmeter is reading properly, my readings on the fuel tank sending unit were about 80-90 w/ float at lowest, and 0 w/ float at highest (sound about right?)

Thanks for walking me through all of this--you are a life saver!
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Old 03-02-2014, 06:44 PM   #8
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PS--I left the pump out while I did these checks, don't know if that would make a difference (I'll go stick the pump back in and run them again since I know now the pump is good).
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Old 03-02-2014, 07:17 PM   #9
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PS--I left the pump out while I did these checks, don't know if that would make a difference (I'll go stick the pump back in and run them again since I know now the pump is good).
It's OK that you did it with the pump out. The zero volt reading on the output of the relay contact says that the relay is bad. The gentleman in the other thread just shipped his bad one to me this past week, so I will soon have it in hand to determine the cause of the failure. Considering that the relay coil is good, I suspect that I am going to find that the problem is not the relay, but rather a circuit board trace that was not properly sized and eventually failed.
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Old 03-02-2014, 07:28 PM   #10
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Update:

Quote:
If that looks fine, you can fire the relay using a 9 volt battery and two pieces of wire. Connect one terminal of the battery to pin 2 and the other to pins 3 and you should hear the relay click closed.
Tried this again, and what I got was a constant clicking from the relay... couldn't really get a resistance reading on pins 1 and 4, though (it was intermittent, flashed in the 170s/ 180s I think briefly a few times, but nothing consistent).
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Old 03-02-2014, 07:37 PM   #11
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Update (again)

Just put the pump back in, and turned the key on to see if I could now hear it running. No sound from the pump w/ key on, but fuel gauge is now flashing empty!
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Old 03-02-2014, 08:15 PM   #12
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Update (again)

Just put the pump back in, and turned the key on to see if I could now hear it running. No sound from the pump w/ key on, but fuel gauge is now flashing empty!
Try jumping the 4A-8 and 4B-11 black wires together and see if the fuel pump runs.
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Old 03-02-2014, 09:08 PM   #13
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OK, did it-- it DOES run when the key is in the ON position.
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Old 03-02-2014, 09:15 PM   #14
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Well, this is getting stranger and stranger. I had disconnected the battery (before I jumped 4A-8 and 4B-11) to reset everything. Now, after reconnecting the bat, the fuel gauge seems to be reading accurately (4 bars) and the car WILL start, but it will only run for 3-5 seconds... sign of progress?
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Old 03-02-2014, 10:32 PM   #15
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Well, this is getting stranger and stranger. I had disconnected the battery (before I jumped 4A-8 and 4B-11) to reset everything. Now, after reconnecting the bat, the fuel gauge seems to be reading accurately (4 bars) and the car WILL start, but it will only run for 3-5 seconds... sign of progress?
Disconnecting the battery made the instrument cluster reset and take an initial absolute reading of the fuel level. When you do a partial fill and don't drive the car, it takes quite a while for the instrument cluster to believe that the level changed.

With those two jumped, I would expect it to keep running. Did you jump it in a solid way, where the connection won't be intermittent?

Also, measure the voltage on 4E-5 (violet wire) With the ignition switch in the ON position and then again after it stops running (without turning the key off).
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Old 03-02-2014, 11:23 PM   #16
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It's alive!

Well, I had not actually tried to start the car with that jumper wire in. But I realized why it was not running for more than a few seconds--I had never put the intake hose (coming from the air filter) back together from when I had sprayed the starting fluid. Once I did that, I put the jumper wire in, and presto, it started up and kept running. I pulled the jumper wire, and it kept on running as if nothing had ever happened! Drove down the road and back about a mile, through all gears, just to be sure--running like the Toyota I know and love!

So should we chalk this up to a case of a bad connection that happened to get tightened up as I went through everything, or should I expect further troubles down the road? As for me, I'll just go about my normal commute and mark it as a miracle (I actually had prayed that I would get this fixed without spending any money on it! The Lord works in mysterious ways... ;-)

Thanks for all of your help--especially Scott.
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Old 03-03-2014, 10:01 AM   #17
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Originally Posted by tylerwatts53 View Post
Well, I had not actually tried to start the car with that jumper wire in. But I realized why it was not running for more than a few seconds--I had never put the intake hose (coming from the air filter) back together from when I had sprayed the starting fluid. Once I did that, I put the jumper wire in, and presto, it started up and kept running. I pulled the jumper wire, and it kept on running as if nothing had ever happened! Drove down the road and back about a mile, through all gears, just to be sure--running like the Toyota I know and love!

So should we chalk this up to a case of a bad connection that happened to get tightened up as I went through everything, or should I expect further troubles down the road? As for me, I'll just go about my normal commute and mark it as a miracle (I actually had prayed that I would get this fixed without spending any money on it! The Lord works in mysterious ways... ;-)

Thanks for all of your help--especially Scott.

That is pretty wild. There may be an intermittent connection that temporarily resolved by manipulating the wires.

I completely took apart one last night and was amazed that rather than a circuit board, there is a mass of wire inside that makes the connections between the various functions. There is a small circuit board on the back side, which is the actual body ECU, but other than that it is all punched down wire connections. The relay that you were bypassing is one of the four on the lower right side of the rightmost section.

I suspect that your problem will eventually come back, but at least now you know which wires to jump to get it back going, so you don't get stranded.

Body ECU Open.jpg
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Old 03-03-2014, 04:26 PM   #18
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Wow, sure am glad I did not have to pull that body ECU out!

Car ran fine all day today, so I'm hoping this is the end of it. But, as you said, now I at least know how to "hotwire" the fuel pump relay if indeed this occurs again (the MacGyver solution!)

Thanks again, Scott!

PS--I love your Yaris utility vehicle/ snow plow! Has that thing kept up with all of the snow this year? I would LOVE to have a factory-built Yaris pickup--a Yaris version of the old VW Rabbit mini trucks...
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