Discussion
I have just obtained a Gunsons Fault Code Reader for £9 new on e Bay. I have an S3c and frustratingly cannot find where to plug it in!!!! I have pulled down the carpet and found the EEC 1V module which is the 88BBLB type.
The only socket that I can find to plug the Gunson tester in (3 pin type correct for an S3c 2936cc catalyst car) is white with a red end having the wiring colours
brown/red
brown/blue
yellow blue
According to the Steve Heath book this is the octane adjustment plug?
Any suggestions as to where to look gratefully received. I have removed the glove box and the loose harness in the area of the EEC 1V box and fuse box.
The only socket that I can find to plug the Gunson tester in (3 pin type correct for an S3c 2936cc catalyst car) is white with a red end having the wiring colours
brown/red
brown/blue
yellow blue
According to the Steve Heath book this is the octane adjustment plug?
Any suggestions as to where to look gratefully received. I have removed the glove box and the loose harness in the area of the EEC 1V box and fuse box.
The SD connector, octane adjustment and ac clutch connector in my S3 are all located in the passenger footwell. the colours of wire you describe match my octane adjustment connector and as my ECU is also an 88BB it doesnt have any link wires as no adjustment is necessary.
both the SD and Octane connectors have caps that need removing to show the terminal socket, depress the "button" on the flat side of the connector and the cap can be slide out by pulling on the tag. I'm lucky enough to have wiring with colors that match the wiring diagram, if your looking at the end of the connector with the flat on the bottom, ie brown green=top of the triangle, brown=bottom left, blue green=bottom right.
bil
both the SD and Octane connectors have caps that need removing to show the terminal socket, depress the "button" on the flat side of the connector and the cap can be slide out by pulling on the tag. I'm lucky enough to have wiring with colors that match the wiring diagram, if your looking at the end of the connector with the flat on the bottom, ie brown green=top of the triangle, brown=bottom left, blue green=bottom right.
bil
Believe it or not I am pretty sure that I have now found the relevant plugs. The octane adjust is white with a red coloured end that fits the Gunson fault code reader, but is of course the incorrect plug.
The diagnostic plug is also white and has 3 male pins and has brown, brown/green and blue/green wires. It does not fit the input plug for the Gunson reader, so I will have to make a suitable adaptor lead. I have photographs but cannot paste them to this message at present!!
The diagnostic plug is also white and has 3 male pins and has brown, brown/green and blue/green wires. It does not fit the input plug for the Gunson reader, so I will have to make a suitable adaptor lead. I have photographs but cannot paste them to this message at present!!
I have exactly the same wiring as Baggiebird (1990 S3C). I didn't notice the flat connector before because it's right up against the bulkhead where the main loom comes through into the footwell.
A couple of years ago I plugged 2 different diagnostic testers (A gunson's and one I made myself) into the triangular one and got no codes at all. A garage also tried theirs - again nothing.
My gunsons one and the home made one both worked on another car, so I thought my ecu or wiring was faulty.
I'm going to try the other socket - the one with the wiring colours as per the bible as in baggie's car - with my home-made code reader (I can change the connectors on that easy) and see how that goes.
A couple of years ago I plugged 2 different diagnostic testers (A gunson's and one I made myself) into the triangular one and got no codes at all. A garage also tried theirs - again nothing.
My gunsons one and the home made one both worked on another car, so I thought my ecu or wiring was faulty.
I'm going to try the other socket - the one with the wiring colours as per the bible as in baggie's car - with my home-made code reader (I can change the connectors on that easy) and see how that goes.
This has turned into a really interesting one. Thanks again for all contributions, nice to know (tvrgit) that I am not alone.
Yesterday afternoon I scotchloked 3 wires into the wires leading to the connector that I reckon is the correct one, ie the one with 3 male pins. I then connected these to the gunson plug using cut off spade terminals. I tried to connect the colours as Bil describes for his car
Partial result in that the Gunson reader clearly takes control of the engine in 'service mode' the revs rising to 1500, then 2000 rpm. I was then able to re-set the timing to 12 deg btdc in 'service mode', which was all I really wanted to do!!!! However there are no led codes shown on led of the reader?!
It is just so surprising that the connector shapes and colours changed, I guess that garages with expensive diagnostic kit have the necessary adaptors to suit?
Yesterday afternoon I scotchloked 3 wires into the wires leading to the connector that I reckon is the correct one, ie the one with 3 male pins. I then connected these to the gunson plug using cut off spade terminals. I tried to connect the colours as Bil describes for his car
Partial result in that the Gunson reader clearly takes control of the engine in 'service mode' the revs rising to 1500, then 2000 rpm. I was then able to re-set the timing to 12 deg btdc in 'service mode', which was all I really wanted to do!!!! However there are no led codes shown on led of the reader?!
It is just so surprising that the connector shapes and colours changed, I guess that garages with expensive diagnostic kit have the necessary adaptors to suit?
Sorry for my question in this very OLD thread, but I want to try to diagnose my S3C this week-end.
I made my reader. I know I have to search for a 3 wire socket near the ECU. I know the 3 wires are Brown, Brown/green and Blue/green. I know the brown wire is a ground, the Brown/green is connected to the ECU #17 pin, the Blue/green is connected to the ECU #48 pin.
But to do the procedure, I have to plug my box to a pin "A" and interconnect "B" and "C" with a jumper. I know to identify A, B and C on the round (5-pin) socket and on the other model (also 5-pin socket), but I'm not sure on this 3-pin socket
I think Brown and Blue/green have to be interconnected. "A" should be Brown/green and is used to plug my box. Could you please help me ?
Regards
I made my reader. I know I have to search for a 3 wire socket near the ECU. I know the 3 wires are Brown, Brown/green and Blue/green. I know the brown wire is a ground, the Brown/green is connected to the ECU #17 pin, the Blue/green is connected to the ECU #48 pin.
But to do the procedure, I have to plug my box to a pin "A" and interconnect "B" and "C" with a jumper. I know to identify A, B and C on the round (5-pin) socket and on the other model (also 5-pin socket), but I'm not sure on this 3-pin socket
I think Brown and Blue/green have to be interconnected. "A" should be Brown/green and is used to plug my box. Could you please help me ?
Regards
Brown is earth (it earths your diagnostic kit; provides signal earth).
Brown/green should connect to ECU 17; it's the signal output from the ECU (correct terminology STO (self-test output) or just 'MIL').
Blue/green goes to ECU 48; it's the signal input to the ECU (STI). To trigger the test, you (or the diagnostic kit) should briefly ground this wire.
If you have the Gunson 77032 tester, brown on the plug goes to the red wire on the Gunson, brown/green to the blue wire, and blue/green to the green wire.
The Gunson (or any tester) also has a live feed wire (with a croc. clip on the Gunson)
My tester lives permanently connected in the dash tray (except the live feed; this has to be disconnected to end the test, so I just take the wire with the croc. clip over to the battery when I want to use it).
And it works, and it makes sense!
Good luck!
Brown/green should connect to ECU 17; it's the signal output from the ECU (correct terminology STO (self-test output) or just 'MIL').
Blue/green goes to ECU 48; it's the signal input to the ECU (STI). To trigger the test, you (or the diagnostic kit) should briefly ground this wire.
If you have the Gunson 77032 tester, brown on the plug goes to the red wire on the Gunson, brown/green to the blue wire, and blue/green to the green wire.
The Gunson (or any tester) also has a live feed wire (with a croc. clip on the Gunson)
My tester lives permanently connected in the dash tray (except the live feed; this has to be disconnected to end the test, so I just take the wire with the croc. clip over to the battery when I want to use it).
And it works, and it makes sense!
Good luck!
Edited by mentall on Friday 15th November 15:24
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