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

[jdolondriz]

That's what I was thinking as well coz ecu had no pinout for another o2 sensor. I dont think i have heated coil o2 relay. I think this sensor is tapped directly somewhere coz my previous electrician didnt do things correctly.

[Hassan1991]

Wire it up according to diagram.
Although there's no relay in the diagram for o2.
HT and Ox1A connects to ecu directly.
These codes are permanent? Have you tried clearing them up?

[OwaisYunus1]

Applying a fixed resistance value may not be the way to go as the 02's value changes with temperature. If you dont have catalytic converter, you still would need the 2nd O2, except that you can add a bung and then install the 02 sensor. That helps in fooling the 02 sensor that the catalytic converter is in place. This is what it looks like

[OwaisYunus1]

Can you please specify which picture?

[jdolondriz]

Everytime I clear them, it goes back after scanning

[jdolondriz]

I was referring to this picture Sir. Thank you.

The ecu pinout picture. I think this is the fielders 2002 service manual.

[jdolondriz]

Does this mean the code refers to o2 sensor one since my exu does not have o2 sensor 2?

[Hassan1991]

I still doubt it.
As second o2 used to be simple non heated.
And it's present for the efficiency of catalytic converter and no you cannot bypass it that easy.
Although yes error is of 2nd o2 but only for heated circuit.
Look in the wiring and see if pins are there for second o2.

[jdolondriz]

But it is ok to run with this error?

[Hassan1991]

No. It can cause ecu to run in open loop.

[jdolondriz]

Would it be possible that sensor 1 is causing the problem and not sensor 2? Coz I dont have sensor 2 in ecu pinout and no sensor 2 connected. Could it be bad sensor 1 wiring?

[OwaisYunus1]

Unfortunately, the pinout is the only thing that I had, not the complete manual. I've searched for it, but I wasnt able to find it.

[jdolondriz]

Thank you. Im having problems since ecu has no ox1b. Ecu only has 1 o2 sensor but p0037 is saying sensor 2. Not sure which pinout to check

[Hassan1991]

Search for the code specific to your ecu.
These applications gives general explanation of codes.

[jdolondriz]

I checked and there is no 2nd o2 sensor mounted. This might be the reason for the code. Im just wondering if it is ok to ignore it since i believe the 2nd o2 sensor only checks cat function (i dont have a cat and this would be useless)?

[jdolondriz]

I was wondering if the wire colors stays the same in different ecu's of 1nz? Coz I've checked and in other ECU, OX1B is L = light blue or is this blue. Upon checking my ECU, there is only 1 wire with that color.

[Hassan1991]

No you need to clear the error.
It is not necessary that wiring color code will be same as it depends upon from which car wiring came out and from which region as well.

[jdolondriz]

Is there a way to trace the wires for H02S2 (o2 bank 1 sensor 2) from the ECU? It is easy to purchase a new sensor and mount it but the connector is missing. I believe I need to wire it independently.

Currently, this is the working pinout that I used for TACH and OBD diag port wiring. However, OX1B is missing. Anyone has a more detailed pdf of this diag?

https://imgur.com/a/lOcoKxg

[Hassan1991]

Look at the diagram i shared.
Take the first o2 off and see if it also throws primary o2 code.
Then you need to install 2nd o2 according to the diagram.

[jdolondriz]

I disconnected the 1st o2. It threw off a different code - p0031. It has the same description but pertaining to bank1 sensor1. It seems this code is related to disconnected o2 sensor. This is similar to the old code - p0037 that in getting. It is sure that I dont have the 2nd o2 sensor - bank 1 sensor 2. The real problem is locating the ecu pinout.

Here are the error codes (p0031 is the code when I disconnected 1st o2 sensor - bank1sensor1)

I understand the diagram but don't know where the HT and OX1B pinouts are.

I also saw this connector in the wiring harness. It is located near the ecu. Not sure what it does. It has a cover as well.