Help needed to convert OBD1 to my OBD2 T-5R

[simonc]

I typed title incorrectly lol sorry. My T-5R is running 4.4 ECU and I want to convert to OBD2 port, can anyone help and tell me what I need to do? Obviously a OBD2 port and sone wiring but not sure how to do it as can’t find anything on the net.

Thanks
Simon

[Dangerous Dave]

Is it the non immobiliser M4.4 ecu? If so you should be able to run a wire from pin 7 on the OBD connector to pin B36 on the ecu. Then standard OBD pin 4 to ground and OBD pin 16 is +12V.

Check this thread out
https://www.matthewsvolvosite.com/forums/viewtopic.php?t=77600

[simonc]

Thanks for the reply.

How will I know if it’s non immobiliser ECU?

[Dangerous Dave]

Thanks for the reply.

How will I know if it’s non immobiliser ECU?
Depends on who fitted it and what they did to it. If it has been flashed with the non immobiliser map then it will work. But if someone just put a normal m4.4 ecu in then it won't work (unless it is the non immobiliser version of that ecu).

Did someone else fit it then?

Otherwise there is no way to tell without reading the eprom in the ecu.

[simonc]

Ah ok right. I’m ok doing mechanical work and a bit of wiring but know zero about ECU’s and reading codes etc. Hence wanting to fit OBD2 port myself so I can read the codes and have more understanding and be able to maintain the car in full myself.
I know the previous owner had Shemtek put the tune on the car and quite a bit of work done there. Shem has offered to help so I’m going to ring him in the week. Another reason for wanting OBD2 is to go to the next stage of larger injectors, new fuel pump and MAF but I know OBD2 port is needed for mapping at that stage.

Thanks
Simon

[Dangerous Dave]

It's possibly the non immobiliser version then if Shem has mapped it. But yeah have a word with him as only he'll know.

[simonc]

Haven’t been able to get hold of him this week. Maybe he’s on holiday. Will try next week.

Assuming it’s not immobilised, all I need is a female 16 pin socket and some wire?

I’ve read it’s 3 wires,
1. Earth
2. Live, switched or perminant?
3. Wire to ECU but which pin? I’ve read some say B36 some say B5 or maybe that’s wrong.

What code reader would I need to buy, only want to read engine fault codes.

[Dangerous Dave]

Live is usually permanent on the OBDII socket.

As for a reader a cheap Bluetooth one of eBay will suffice and download Torque app to connect your phone to read the codes.

I'll see if I can dig out the wiring diagram so you can see which pins to connect to

[simonc]

I found a link in this thread
http://www.vpcuk.org/forums/showthread.php?56982-Converting-OBD1-too-OBD2

which has the diagram, will have a go later in the week as I’ve got my OBD 16 pin female port now. Just got to work out where I want it in the car and run wires.
What’s the best way of getting to the back of the ECU plug to get to pin B36? Do you know if their is already a wire connected to that pin that I could tap into. I’m a bit worried of disturbing the loom as it’s old. I can see you just lift out the ECU but not sure how to get to the back of plug/loom.

Thanks

[simonc]

I’ve wired in the live and earth to OBD2 socket just got to run wire through to ECU. Decided to put it in the glovebox. What’s the easiest way to connect a wire to B36? Does the ECU housing just lift out or can I just tap into a wire coming off B36?

https://i.postimg.cc/rmb1yzXT/D1-D32117-38-C9-4557-9-E9-A-B318-C42-B90-F5.jpg (https://postimg.cc/ygmgv18p)

Thanks

[simonc]

This may help others who want to wire in OBD2 port as I struggled to find any info.
https://i.postimg.cc/d1ZzB0Gt/A843-A9-DC-15-FF-45-B6-B896-83-CA9-F2-DFA20.png (https://postimg.cc/BLsYZ4hd)

[simonc]

Finally finished install and got it working ok, can read codes etc with Torque app now.

[kmb]

Good news, any noticed differences?

I was running my 850 T5 on a mapped M4.4 (done by Oblark on here) and it seemed to run much more smoothly and of course more power on the mapped M4.4, with the added bonus of being able to read and reset codes etc. with Torque App.

[simonc]

It was already on a mapped 4.4 by Shemtek when I bought it. All I’ve done is wire in a OBD2 port to read codes. No codes stored. Should be useful though as when I take it to the rolling road they will be able to check the AFR through port as last time they couldn’t check.

[Dangerous Dave]

Has it got the wideband mod then?

[simonc]

Has it got the wideband mod then?

All I did was run wire to B36 and then earth and live. Can read codes ok. Is their more I need to do? Just assumed they could check my AFR through OBD port. I’m not really up on all this stuff but trying to learn.

[Dangerous Dave]

No worries, there's lots to learn :)

Unfortunately it is not possible to read the AFR from the standard ecu as it uses a narrowband O2 sensor which can't read a wide range of AFR. So AFR is not an option via OBD2. You can read the fuel trims and sensor voltages but as it runs on an old OBD protocol the refresh rate is dog slow.

To get full fast AFR (and other parameters) value streaming you need to have the modified ecu binary that the Volvospeed guys have been developing and have a wideband O2 sensor fitted.

More info here:
https://m44.fandom.com/wiki/M44_Wiki