Need assistance setting up PLX wideband

[gpc]

Hi

I've been trying to set up a PLX wideband with the MPV1 interface. I can see it in the channels but reading stays at 10.0. Here is a screen shot of the channel set-up if it helps at all.hp screenshot.png

[schpenxel]

Post a log

But if you're just getting a flat 10.0 then the HPTuners interface is not receiving a 0-5V signal, so I would double check the wiring. Make sure you're using the correct output from the PLX WB and also make sure have it connected to the correct port on the HPTuners interface

Also be sure that you have a GROUND wire connected between the WB and HPT

[gpc]

Thanks for your reply. There is a little history with this. I've been working back and forth with PLX for a week or so. They had me run a series of tests and everything checks out good. What we found was that with the PLX functioning I can unplug the green connector from the MPV1 and voltage reads within the specified range, with the volt meter still on the connector as soon as you plug it into the MPV1 the voltage reads zero. Unplug it from the MPV1 and voltage reads correct again.

[gpc]

Actually it bounces from 10.0 10.01 although I don't think that's significant. Here is a log of a sample reading

[schpenxel]

Can you post a picture of the PLX end of the wiring also?

[gpc]

I also have pics of all the readings taken from the PLX as instructed by them if of any use.

[schpenxel]

Have you tried connecting it to a different input?

[gpc]

I did try and got the same results. I also tried adding a second ground to a different location. Before doing the diagnosing with PLX I also tried a new sensor just to make sure but after testing the PLX reads correctly when not connected with the MPVI. I'm at a loss.

[schpenxel]

I just noticed something--in the first multimeter pictures, the one with 5.61V.

Is it showing -5.61V or +5.61V?

[Tre-Cool]

The way to setup a plx is:

1) unplug power from plx
2) place plx in bin
3) buy another wideband
4) install other wideband
5) enjoy tuning

[gpc]

I noticed that during testing and mentioned it to the tech but he said everything was normal.

[gpc]

I've been ready to do it for a while but am so involved in figuring this out. lol. Are you speaking from experience?

[schpenxel]

I noticed that during testing and mentioned it to the tech but he said everything was normal.

That doesn't seem normal to me but what do I know. Are the leads on the multimeter in the "correct" spot?

I've used a PLX WB for the better part of a year without any issues. I'm using an AEM 30-0333 now but only because it's faster and I wanted to try it..

The PLX I received actually had the wires that go to the little gauge wired backwards, so that makes me wonder if something is backwards on this output too, though I hate to tell you to start switching things around.. I don't want to be responsible for frying something. I'm almost sure that shouldn't be reading negative though.

[gpc]

The power cable is clearly marked RED +, BLACK - Could something be wired wrong in the module? I suppose it could be. Could they have the wires reversed on the plug itself? I suppose it could be. I'll look into this more tomorrow as I am curious. I could reverse the wires and see if it switches to V+, at worse it will burn out the module which is proving useless to me as is.

[mowton]

The way to setup a plx is:

1) unplug power from plx
2) place plx in bin
3) buy another wideband
4) install other wideband
5) enjoy tuning

.....cute

Ed M

[schpenxel]

The power cable is clearly marked RED +, BLACK - Could something be wired wrong in the module? I suppose it could be. Could they have the wires reversed on the plug itself? I suppose it could be. I'll look into this more tomorrow as I am curious. I could reverse the wires and see if it switches to V+, at worse it will burn out the module which is proving useless to me as is.

Yeah, I'm really thinking something is wired backwards internally somehow. Mine had the wires for the gauge ran backwards and it wouldn't work out of the box. I had another gauge from a second PLX I had been given, and that one worked. Later I figured out the wires were backwards from the factory.

So, I personally would probably try connecting them the opposite way and see what happens. Hopefully nothing gets fried in the process but no guarantees.

I would get everything scanning first then just briefly connect the wires and see what happens in Scanner

[gpc]

I'll try it and see if the voltage output is normal before connecting it to the MPVI just in case.

[gpc]

Had a chance to do some testing and have come to the conclusion this thing is getting canned. When reversing the ground and WB out terminals the voltage readings switch to V+ but also read 8.0 volts, the maximum output should be in the 5v range. Also as soon as I plug it into the MPVI the AFR shoots to 19.8 which I am thinking is the upper range the MPVI will read.

Makes me think this thing is wired wrong internally and the MPVI is reporting the signal in.

Any thoughts on that?

[schpenxel]

I agree

[gpc]

Getting back in touch with PLX to see what they think, this is a new unit.