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Code reader plug

Code reader plug

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SteveOS3

Original Poster:

381 posts

109 months

Sunday 18th June
quotequote all
I've been trying to get to the bottom of a sudden increase in fuel consumption, about 5 mpg less. I had the emissions tested and it's kicking out about 4x more than it should.

I checked and cleaned the air flow meters, they were pretty dirty, I haven't cleaned them in 8 years of ownership, but it made no difference.
Checked and cleaned the connectors on the engine temp sensor, no difference.

The boys in my local garage have lent me a old SnapOn code reader with a Ford 3 pin adaptor to try and get more info'. However, there are two plugs in my wiring loom;

The first photo shows the one that fits the SnapOn adaptor kit but it doesn't seem to communicate with the reader. The second photo doesn't fit any of the Ford adaptors. Can anyone confirm which is the correct plug?

Plug 1


Plug 2


Plug 1 is the only one that fits the SnapOn adaptor for a Ford 3pin but it doesn't communicate.

When we used a probe to test plug 1 we got the following reading:

Ignition off - all connections show Negative
Ignition on - Top pin negative bottom left negative bottom right no signal
Engine running - top pin oscilates live/negative bottom left negative bottom right no signal

Plug 2 reads negative in all three pins with ignition off and nothing in all pins when ignition is on and when engine running.


The wiring traces back to the ECU and all connections are in place there.

I'm going to replace the engine coolant temperature sensor as a matter of course but would appreciate knowing if I am using the correct tester jack plug.

Cheers,

Steve


Edited by SteveOS3 on Sunday 18th June 11:04


Edited by SteveOS3 on Sunday 18th June 11:08

RayTVR

667 posts

61 months

Sunday 18th June
quotequote all
Top one looks like the one on mine (but there are different ones I've seen in the past)


Best way to check is the wire colours. Diagnostic connector should have Brown, brown/green and brown/blue wires.


h271mbk

39 posts

17 months

Sunday 18th June
quotequote all
Hi, there are a couple of code reader connection options used on the cologne v6. Have a look on the Gunson website at their instructions for their code readers (Vehicles with EEC IV Electronic Control Unit (3 pin) Plus early vehicles with 5pin diagnostic connector). There's also pictures of the different connectors used and useful info on how to enter service mode in the instructions should you need it.
N

SteveOS3

Original Poster:

381 posts

109 months

Sunday 18th June
quotequote all
I've got that colour combination on plug 1, Ray

Just need to figure out why it isn't communicating.

Cheers.

RayTVR

667 posts

61 months

Sunday 18th June
quotequote all
I've not used a Gunson type one before, but I do have one of the Ford 'Star testers' which are the original tool used in dealers.

There's a couple of them in the community - If you need to borrow one, I'm sure we can work out logistics, Or come along to S Club and I'll have it with me.

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h271mbk

39 posts

17 months

Sunday 18th June
quotequote all
Link to Gunson instructions:

http://www.gunson.co.uk/items/pdf/products/g4160_g...

Worth a quick look, even just to identify the connector type. My 1991 2.9 car has the later 3 pin connector with a red blanking plug in it for protection/identification (as per Gunson instructions)

Once you know which connector it is it's worth buying a code reader off fleabay, I have both and they cost less than £5 each

Good luck
N

Spathodus77

300 posts

127 months

Sunday 18th June
quotequote all
I was using my Gunson 77032 today so can offer the following advice. This is also based on Gerald TVRs expanded instructions for the star tester (I've lost my electronic copy of these but someone else maybe able to send them to you). There is also a diagnostics article from car mechanics (Feb 95) which is a good source of info.

The diagnostics connector on the car is usually under a black cover the octane adjust is under a red cover.

As has previously been stated the wires going into the diagnostics socket should be: Brown, blue/green, brown/green. I found the blue/green to be of a similar shade to the point where the wire just looks blue. If correct the blue/green and brown/green wires can be traced back to pins 48 and 17 on the ECU very easily.

One thing you may have neglected to do is to cut the Octane adjust wire before plugging the tester in (although later cars may not have this). According to the star tester notes "disconnect octane and idle adjust wires if grounded". On my car there is a brown/red wire going into the back of the octane adjust socket with a black wire sliced into it. The black wire has been cut and a connector put into it so it can be connected/disconnected whenever diagnostics are required.

Good luck and let us know the cause when you find it.

Ralph

SteveOS3

Original Poster:

381 posts

109 months

Sunday 18th June
quotequote all
Ordered a Gunson 77032 earlier today and will look for any wires that need cutting on the octane sensor.

Many thanks for everyone's advice.

SteveO

SteveOS3

Original Poster:

381 posts

109 months

Monday 19th June
quotequote all
Link to the 77032 manual

Off to cut some wires.....

http://www.gunson.co.uk/items/pdf/Products/77032_I...


SteveOS3

Original Poster:

381 posts

109 months

Monday 19th June
quotequote all
Hmmm, took a look at the wiring on the octane connector and everything matches the wiring diagram below and the ECU connection numbers.

It's the Blue/Yellow wire that goes to earth on the diagram. Is this the one to be disconnected?



Cheers

Spathodus77

300 posts

127 months

Monday 19th June
quotequote all
On an S3 you may not need to cut any wires - this is what I meant by 'a later car'. This is the limit of my knowledge. Unfortunately I can only advise based on what I observe with my own car - on mine the black wire is cut.

If you disconnect the battery can you use a multi-meter to check for continuity between your suspected earth wire and a known earth point?