Mystery plug/socket not connected

[shane_1]

Hi all, after having a radiator replacement, i've noticed a plug & socket not connected, perhaps missed by the radiator installer.
It's located just down under the battery ... see the image.
I'm assuming it should be plugged in, and will do after any feedback.
It has 3 x flat pins and appears to have some other smaller needle like pins, but i dont have my glasses on
Any hints as to what it is ... nothing is untoward when driving ... except atrocious fuel economy & black smoke on accelleration, of which I'll deal with separately.

 

[GunMentalGrey]

What year and model?

It’s not unusual to have a single wiring loom that covers multiple models and extra features are just not connected. Makes it easy for the factory. Wouldn’t be good to get half way down the line and find they’ve installed a base spec loom and can’t then install any of the top spec features.

E.g. my 2007 STX didn’t come with a temp display. I bought the sensor and plugged it to the factory point and it instantly worked. There are also plenty of spare slots in the

 

[shane_1]

2007 D40 manual. I too don't have an outside temp sensor

 

[Old.Tony]

There's a number of objects in that area that the plugs could be for:

1) Glow plug relay. If this isn't on, the glows won't light. Starting will be a little more difficult (not much though, hard to tell) but you can test the voltage on the glows when the ignition is turned on (cold engine). Takes 2 people to do this properly.

2) Boost sensor. This lives down near there, and should be plugged in. You'll know if there's no boost reading. Cheapest way to determine this is to get a bluetooth OBD adapter (ELM327) and some software on your phone that can query the ECU (Android - Torque is what I use). If boost pressure doesn't change at all, ever, then this is the culprit. This will cause you to have inaccurate metering of the fuel, so it could end up blowing all sorts of smoke (well, white/grey or black, you should never see green or red smoke ever).

3) Fog light harness. Most models (including mine, and mine's a top-of-the-range) didn't include fog lights. As the others have said, the harness is made for multiple models.

 

[landmannnn]

Looking at the plug/socket, it looks dirtier on the body than on the.end, that would suggest it has spent most of its life plugged in.

 

[shane_1]

There's a number of objects in that area that the plugs could be for:

1) Glow plug relay. If this isn't on, the glows won't light. Starting will be a little more difficult (not much though, hard to tell) but you can test the voltage on the glows when the ignition is turned on (cold engine). Takes 2 people to do this properly.

2) Boost sensor. This lives down near there, and should be plugged in. You'll know if there's no boost reading. Cheapest way to determine this is to get a bluetooth OBD adapter (ELM327) and some software on your phone that can query the ECU (Android - Torque is what I use). If boost pressure doesn't change at all, ever, then this is the culprit. This will cause you to have inaccurate metering of the fuel, so it could end up blowing all sorts of smoke (well, white/grey or black, you should never see green or red smoke ever).

3) Fog light harness. Most models (including mine, and mine's a top-of-the-range) didn't include fog lights. As the others have said, the harness is made for multiple models.

Thanks Tony, I have a cheapo OBDII plugin version with me. We're camped out Ligntning Ridge northern NSW atm, staying at a wonderful Farmstay property.
I'll plug that in and see if it gives me Boost readings ... never used it so not sure what it'll show me.
I'll go with answer 2 first, as I don't have voltmeter with me, even though with the new battery she starts instantly once plugs are warmed.
I have fog lights installed ... aftermarket, but I didn't install them so not sure how they were wired in.

 

[Mortalcabbage]

Please excuse if this a stupid answer but whatever it was plugged into should be nearby and is it in hiding in the dark below centre of the photo?

 

[shane_1]

Please excuse if this a stupid answer but whatever it was plugged into should be nearby and is it in hiding in the dark below centre of the photo?

yep, found the plug and socket.

 

[shane_1]

There's a number of objects in that area that the plugs could be for:

1) Glow plug relay. If this isn't on, the glows won't light. Starting will be a little more difficult (not much though, hard to tell) but you can test the voltage on the glows when the ignition is turned on (cold engine). Takes 2 people to do this properly.

2) Boost sensor. This lives down near there, and should be plugged in. You'll know if there's no boost reading. Cheapest way to determine this is to get a bluetooth OBD adapter (ELM327) and some software on your phone that can query the ECU (Android - Torque is what I use). If boost pressure doesn't change at all, ever, then this is the culprit. This will cause you to have inaccurate metering of the fuel, so it could end up blowing all sorts of smoke (well, white/grey or black, you should never see green or red smoke ever).

3) Fog light harness. Most models (including mine, and mine's a top-of-the-range) didn't include fog lights. As the others have said, the harness is made for multiple models

Tried my cheapo OBDII reader, and it just displays "no codes" and nothing else useful i could scroll through. Just did it with the ignition on, but not started.

So I plugged the two plugs together anyway.

Drove a coupla hundred kms out to the Opal fields, nice flat country. No discernable difference in anything.
@Old.Tony what exactly is the "Boost sensor &/or Boost pressure?" ... or what does it "Boost"?

I intend to purchase that bluetooth obd when I return from travels.

 

[Old.Tony]

Boost sensor measures the amount of pressure in the intake produced by the turbocharger. It's used directly by the ECU (along with other data) to calculate the amount of fuel that can be injected into the engine.

A workshop reader may only display codes (especially if it's not a full-on diagnostic tool. The OBD adapter will allow software on your phone to talk to the ECU (for query, not for changes).

 

[shane_1]

Boost sensor measures the amount of pressure in the intake produced by the turbocharger. It's used directly by the ECU (along with other data) to calculate the amount of fuel that can be injected into the engine.

A workshop reader may only display codes (especially if it's not a full-on diagnostic tool. The OBD adapter will allow software on your phone to talk to the ECU (for query, not for changes).

Thanks Tony, i may have to revisit that as i've noticed the turbo making slight "pinging" noises just after starting the ute. Seems fine once warmed up. Will check previous forums on diagnosing the noise and the fuel consumption.
Cheers