car will not start after connecting sensor

[mariann]

Help please
after connecting new oxygen sensor the car will not start!
when key at ON possition the check engine light turnd off and the col engine light is blinking.
when i turn the key to start nothing happens.
what is wrong???
i have unplugged the sensor and still the same.
how can i start it just to get to the toyota service place??

[mariann]

Yaris 2007

[CTScott]

The engine will run without the sensor, so I think it may be wired incorrectly and has blown either the 7.5A IGN fuse or the 20A EFI fuse.

[mariann]

The engine will run without the sensor, so I think it may be wired incorrectly and has blown either the 7.5A IGN fuse or the 20A EFI fuse.


it was the efi... it gave me an heart attack....
i put a temporary fuse from the spare one...

[CTScott]

it was the efi... it gave me an heart attack....
i put a temporary fuse from the spare one...

Can you post pictures of the old and new sensor, where the wires go into the sensor?

[mariann]

Yes i can but i will do that tomorow. now its late.
if i remember correctly the old original one have two black wires one blue and one white connected in a cillicone casting to prevent water into sensor. the new replacement one have two white one black and one gray wires.
connected to the sensor with a metal cap that the wires are loos inside and i cannot see the cillicone seal...
hope this help untill tomorow.

[CTScott]

Yes i can but i will do that tomorow. now its late.
if i remember correctly the old original one have two black wires one blue and one white connected in a cillicone casting to prevent water into sensor. the new replacement one have two white one black and one gray wires.
connected to the sensor with a metal cap that the wires are loos inside and i cannot see the cillicone seal...
hope this help untill tomorow.

OK - I just found the diagram for the aftermarket sensors. The two white wires are the heater wires, the black wire is the signal and gray is ground.

If I remember correctly, your Yaris has the 2SZ-FE engine, which would mean that the secondary O2 sensor wires are violet and light green for the heater, green for the signal, and gray for ground. Those colors though are at the connector that the sensor plugs into, as opposed to the sensor itself.

So, if you can verify the old sensor connector to harness connector colors, we can figure out the correct wire color mapping for the new sensor.

[mariann]

Ok. the violette and the light green connected to the heater at the old sensor(two black wires)
and at the new one two whites.
the dark green at the harness connected to the blue wire at the old sensor and to a black wire at the new sensor.
the gray one at the harness connected to white wire at the old sensor. and to the gray wire at the new sensor.

[mariann]

Well. i found a short ciurcit from the heater to the ground.
i found that one of my soldering connection broked and got loose
inside the heat shild. found that and now the sensor seems fine.
13 ohams resistance at the heater and no short ciurcit between any wires.
i have photos of the sensors and connectors that i can email if you would like.
anyway is the harness fine with the new sensor or ill need to rewire.
thanks.

[CTScott]

Well. i found a short ciurcit from the heater to the ground.
i found that one of my soldering connection broked and got loose
inside the heat shild. found that and now the sensor seems fine.
13 ohams resistance at the heater and no short ciurcit between any wires.
i have photos of the sensors and connectors that i can email if you would like.
anyway is the harness fine with the new sensor or ill need to rewire.
thanks.

Excellent! I am glad to hear that it is now working.

[mariann]

I fixed the sensor cable checked it and installd.
i have reset the ecu by disconnecting battery terminal.
now it works fine without the check engine light.
it usually turnd on after a few days and not emidietly
so now i am doing a test run to see if its ok.
ill get back to you when ill be sure its fine.

thanks for all your help.