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Discussion Starter · #1 ·
Hi there,

i have an issue with my 2001 3BG 1.8T 20V AWT.

Engine light goes on, with the fault code P0030 & P0135
(Fault in Preheating system oxygen sensor Bank1 Sensor 1.)

So at first i put a new one in.
But the code came back fast.

My question:
Can someone tell me what values the connector must have in Volts and Ohm? I tought it has to be between 0.1 and 3 volt or something?

First Oxygen sensor before cat:
1 white
2 white9
3 grey
4 black.

Connector on car:
1 Yellow/Green
2 White/Grey
3 Purple
4 Red.

How many Volts and Ohm must it have to work correct? I know, ohms must be zero haha.

Thanks馃檲
 

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At all times while the engine is running, there should be 12V from a fuse on one end of the heater element.
For a short time after a cold start, (the heater will be on) there will be close to zero volts on the other end of the heater element,
when the heater urns off this will go close to battery voltage.
 

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Discussion Starter · #3 ·
Okay,
The heating is only for the start.
i've looked in the instruction book. But i can't find where the fuse should be.
Ishould that be in the motor compartment of in the dash?
 

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Discussion Starter · #5 ·
I've checked all the fuses.
15A(F34)
20A(F29)
20A(F32)
Even like the rest, they are good.

Ogygen sensor disconnected, car.
Cooland is at 50degreese C.
VOLTS:
Car locked: Contact: Running:
1 0.14v 14v 14v
2 3.44v 2.4v/3.59v 2.4v/2.59v
3 0v 0v 0v
4 0.43v 0.44v 0.44v

Oxygen sensor disconected, sensor self.
OHMS between:
1-2 Zero Ohm.
1-3 1-4 2-3 2-4 3-4 Infinitely

So, has the engine be cold-cold to check it?
And are those correct so far?馃槄
 

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I've checked all the fuses.
15A(F34)
20A(F29)
20A(F32)
Even like the rest, they are good.

Ogygen sensor disconnected, car.
Cooland is at 50degreese C.
VOLTS:
Car locked: Contact: Running:
1 0.14v 14v 14v
2 3.44v 2.4v/3.59v 2.4v/2.59v
3 0v 0v 0v
4 0.43v 0.44v 0.44v

Oxygen sensor disconected, sensor self.
OHMS between:
1-2 Zero Ohm.
1-3 1-4 2-3 2-4 3-4 Infinitely

So, has the engine be cold-cold to check it?
And are those correct so far?馃槄
You need to take more care when checking voltages, it is not possible to get near 14V when the engine is NOT running.
The voltage tests must be done with the sensor fully connected.
Check pins 1 & 2 immediately after cold start, and again after engine has reached normal operating temp.
No need to check pins 3 & 4.
 

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Discussion Starter · #7 ·
So i've checked it after a night., So cold start.

Contact
1 0.14v
2 0.14v

Cold start running at secundaire air pump
1 14.2v
2 between 8.65v/14.25v

Running After secundair air pump
1 14.2v
2 between 8.65v/14.25v

So i guess this should not be good?
 

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So i've checked it after a night., So cold start.

Contact
1 0.14v
2 0.14v

Cold start running at secundaire air pump
1 14.2v
2 between 8.65v/14.25v

Running After secundair air pump
1 14.2v
2 between 8.65v/14.25v

So i guess this should not be good?
That could be normal.

"between 8.65v/14.25v" is vague, could you please provide detail.
Also could you do this test after driving at least 10 minutes ?
 
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