57 replies to this topic

[pete l]

I'm starting to wonder if I have a wiring problem, not broken, just not in the right place.

 

I received yet another MAP sensor today and this one does the same as the others. Now this CAN NOT be possible.

 

With the K-series T-MAP sensor I am getting a reading that changes with vacuum, I wired this one up myself, I did not rely on ready made plugs and wiring looms. 

 

Could the wiring in my car be wrong ? could they be crossed ? could the 5 volts that should be powering the MAP sensor be going to the signal pin ???

 

Is there anyone wire a very early MPI that has the early ECU that can take a photo of the MAP plug and wires ?

 

And someone with a late MPI who could do the same ?

 

Mine is a later one but it has an early ECU ***191 and it should have the ***192 ECU ! (i got the car in bits)

 

Someone did mention that the difference between these 2 ECUs has something to do with the MAP sensors. So I'm wondering if there is a wiring difference between the 2.

 

Or if anyone has any ideas about what the F is going on. HELP ME PLEASE.

 

Pete.

[Wiggy]

With the connector plugged in, starting with the wire nearest to the front of the car, I have:

 

Yellow/Purple

Red/Green

Pink/Black - This is shared between the MAP, Coolant Temp Sensor, Inlet Temp Sensor, Throttle Position Sensor

[Sprocket]

Pink black is always the sensor ground. The other two wires are then +5v and the ‘signal’

[pete l]

Do you know which is 5v and which is the signal one ? And what ecu do you have ?/

[Sprocket]

I'm just looking to try and figure this out now. I have a MAP sensor on the shelf somewhere, so I need to find that to work out which is pin one and which is pin three. The wiring diagram says pin one is the pink/black and pin three is the yellow/purple, which obviously means pin two is red/green.

It would be nice to reference that with other applications for this sensor to try and find out which is 5v and which is signal. Bear with me.

[Wiggy]

My black belt in Google Fu has revealed THIS

Yellow/Purple is 5V.

[tmsmini]

Not sure if this will help, but verifies the previous post.

This is my spare loom so no idea what year, but it is the same as my car with a 99 engine.

Attached Files

•  DSC_4756.jpg   31.98K   1 downloads
•  DSC_4757.jpg   33.2K   1 downloads

Edited by tmsmini, 11 June 2018 - 07:13 PM.

[tmsmini]

And this

Attached Files

•  map-sensor.pdf   139.14K   16 downloads

[pete l]

OK. So the middle one is the signal. Pinky one is ground. And what's left is 5v.
This is how I have been testing it all. So all my map sensors are dead. I just can't believe it. How can such a thing be possible ?

[Sprocket]

don't listen to anything I said in this post, its wrong, I did't read Wiggy's post at all well lol .

Edited by Sprocket, 11 June 2018 - 08:31 PM.

[Sprocket]

OK. So the middle one is the signal. Pinky one is ground. And what's left is 5v.
This is how I have been testing it all. So all my map sensors are dead. I just can't believe it. How can such a thing be possible ?

 

 

I would suggest the middle is indeed the signal wire just going off this wiring diagram for a Land Rover Discovery which uses the same 'Ambient' Absolute Pressure sensor.

 

one thing is clear though, there were several mistakes in the Rover Rave CD documentation and diagrams so there is always still some doubt  2000-land-rover-discovery-2-wiring-diagram-regarding-td5-wiring-diagram-defender-forum-lr4x4-the-land-rover-forum-on-tricksabout-net-photos.jpg   65.03K   4 downloads

[Sprocket]

don't listen to anything I said in this post, its wrong, I did't read Wiggy's post at all well lol

Edited by Sprocket, 11 June 2018 - 08:30 PM.

[tmsmini]

I had forgotten that Tom's site was updated. It has alot of information on the MEMS2J

http://www.tom-seven...=start&do=index

 

I have been meaning to buy a DC power supply to test sensors as I have some questions about temp sensors as well, so I went and bought one.

 

So I think I set it up the same way,

No vacuum 4.5 volts

Max I could pull with my leaking tool was .2 volts

 

This is a used MAP sensor that probably came with my spare loom.

A movie clip would show it better, but I needed an extra set of hands.

 

I would let you have this sensor, but I am too far away to help.

Terry

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•  IMG_1473.JPG   75.26K   0 downloads
•  IMG_1475b.JPG   76.48K   0 downloads

Edited by tmsmini, 11 June 2018 - 10:56 PM.

[tmsmini]

Sorry abut the upside down image, I can't seem to rotate it and save it properly.

[pete l]

Hmmm, Do I have crossed wires here ?

 

 map1.jpg   50.53K   0 downloads

 

 map2.jpg   26.72K   1 downloads

 

 map3.jpg   53.16K   1 downloads

 

I will check when I get home for lunch, the colours don't show up brilliantly in these photos but it does look like the + and - are the wrong way round !!!!!!!!!!!!!!!!!!!!!