How to wire in an OBD2 port on 1NZ Charade?

[Hassan1991]

Yes they you need 2nd o2.
Connector B pin no.16 is for HT2 and pin no.5 is for OX1B
Confirm that connector B pin no.8 is for HT1 and pin no.6 is for OX1A?

[jdolondriz]

do you have diagram of your pin no. reference? Coz for the pinout im using, HT1 is B4 and OX1A is B23

This is the one shared by @OwaisYunus1 . I believe this is from Toyota Fielder 2002-2004.
This one worked when I wired the obd2 diagnostic port and the tacho.

[Hassan1991]

Picture isn't clear. It means the pinouts i shared are different then yours.
I don't have specific fielder diagram. Will look for it.
Although it is earlier model pinouts.

[jdolondriz]

SG is the sensor ground that is used for the sensors and is generally in an isolated circuit from the power circuit so look for SG on the ECU. People often connect them together but its always a good idea to keep it separate if the ecu has that feature. I'm attaching another pinout for this ecu that has the SIL and TC in it but the position of TC and TACH are different from the one shared earlier. You need to open the case of the ecu to ascertain which pinout is the correct one for you. The pino…

This is @OwaisYunus1 original post

Here is the attached link of the image

https://imgur.com/a/lOcoKxg12

[jdolondriz]

I think i found the diagram fit for my ecu. 2004 corolla. How do I test if the pinouts for o2 sensor 2 are correct? Obd2, o2 sensor 1, ht1 and tach pinouts are similar in the diagram I found leading me to believe that this is the one.

[Hassan1991]

Share here.
Compare power wires, ignition coil wires and injector wires

[jdolondriz]

98.pdf (3.0 MB)

Here is the pdf.

And here is the image i used for obd2 diag i used

So far, batt, +b, tc, sil, tach, ht1, ox1a, vc, ig1-4. Are all on the same for both documents. I dont know what else to check.

[Hassan1991]

Yes you got the right pinout. For starter wire the same o2 you have to the pins of second and rescan the error code.

[Hassan1991]

This is actually same as 3zzfe same gen corolla.

[jdolondriz]

Could you elaborate on this? "For starter wire the same 02 you have to the pins of second and rescan the error code". Do you mean I have to connect the bank1sensor2 to the pinout and scan codes?

[jdolondriz]

It is weird coz this is 1nz and wiring of corolla is similar. I dont know what happened coz i got it like this from an importer from japan

[Hassan1991]

I means wire the current primary o2 to secondary wires.
Or you can just but the secondary o2.
No worries now you have the correct pinouts.

[jdolondriz]

can i do this to bypass since the second o2 sensor is just for catalytic converter check

[Hassan1991]

Better to install a o2.
Although you can do this.

[jdolondriz]

I will be doing the bypass while I'm waiting for the delivery of my O2 sensor. I understand that 2 resistors will have to be used. 1 resistor for the heated circuit and the other for the signal.

I just have a few questions coz in the diagram. There are 4 wires. Ht +b ox1b e1.

For heater:
Ht -> resistor connected to which wire?

For oxygen signal:
Ox1b -> resistor connected to which wire?

Thank you

[jdolondriz]

Am I correct in my understanding for the temporary bypass that I have to make?

I already have the values with me and will be computing to make sure that it is with the voltage ranges. I believe all would get less than 5v with HT1B line less than 3v and

OX1B will have .2 volts per 200msec which is why I need a capacitor

[jdolondriz]

I also checked and there is no wire coming out of OX1B and HT. I guess I have to open up the ECU to really check the pinouts?

Also, I checked the sensors through obd car scanner. Currently closed loop with A/F of around 14.6. It seems the missing sensor is only responsible for checking the cat converter efficiency and existence. Does this mean it can be left untapped? but I really hate the check engine light

@Hassan1991

[Hassan1991]

Add the pins in the connector. There will be few extra wires in either of connector you can use them.
Better to remove the check light.
I haven't seen the video yet.

[jdolondriz]

I just have a question regarding how the ecu detects the heater on the o2 sensor. It detects voltage how?

And there are two wires for the heater part of o2. One is + and other is negative? Or both + or both -?
@Hassan1991 @OwaisYunus1

Is this how the heater element is wired?

Thanks in advance

[Hassan1991]

Current loop cannot be closed without + and -
Ecu provides ground to coil while + is connected with the ignition.
Now how ecu knows o2 heater coil is working or not?
Ecu measures either voltages drop or current being drawn when o2 coil operates. If it's not upto that ecu consider coil is bad.