The message from Warwick Barnes contains these words:
CORRECTED VERSION 3 Sept 03 Sorry had a slight orientation problem!
Has anyone got any information on constructing the diagnostics I/O interface board and leads for use with "Testbook" software on a PC???
there is a bit on my site,
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Also
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freediag at sourceforge
I have hopefully identified the pins on the 14cux and have narrowed diagnostics down to
pin 9 white/light green pin 18 white/pink pin 31 black/green looped back to earth when connector not attached to external diagnostic plug but attached to keeper plug in vehicle.
on this basis I am suspecting that pins 9 and 18 are the ISO9141 K & L lines but which is which?
the diagnostic sockets are 5 pin shake proof and the lucas tester diagnostic lead is terminated as follows with an additional connector to connect to vehicle cigar lighter or battery.
x O O x O
where O shows a connection ; and x no wire attached. looking at end
the air suspension diagnostic adapter plug is:- NB female pins come in a male shroud and vice versa female male pins x O O x treating this as 1 2 O O O O x O 3 4 5 male female shroud
then 2 pin female connects to 1 male i.e. straight through then 3 pin female connects to 5 male i.e. straight through then 5 pin female connects to 3 male i.e. straight through then 4 pin female connects to 5 female
this suggests
O x O x O
in the vehicle with pin 1 K or L pin 3 loopback pin 5 K or L
can anybody confirm this and add any useful information, particularly as to which is L and which is K
One source who got a look inside says that ECM pins 9 and 18 run straight to the motorola microprocessor chip's serial ports, and as near as I can determine from Motorola docs these ports are bi-directional so should serve for ISO9141 K & L lines. note they are set to input after a reset!
Now had a chance to examine vehicle 1993 efi 3.9 with lucas 14cux for both efi and air suspension. the wabco is a completely different plug; I am not even going there till I get some solid information.
Air suspension
male pins "O" looking at end. This is end connected to ecu
O x using 1 2 O O O 3 4 5
(this matches adapter cable tester side pins exactly) pin 1 white/green stripe wire 2 not connected 3 black 4 black/pink stripe 5 white/pink stripe
female pins "O" loopback/keeper looking at end
x x x O x
pin 4 black wire pins 1 2 3 5 not connected
Electronic fuel injection
male pins looking at end. This is end connecting ecu to diagnostic cable.
O x using 1 2 O x O 3 4 5
pin 1 white/green (**? ecu pin 9 ) 2 not used 3 black (**? earth) 4 not used 5 white/pink (**? ecu pin 18 )
female pins loopback connector/keeper looking at end
x x O x O
pin 3 is connected to pin 5 which then runs out a black/green wire (**?ecu pin 31)
NB the range rover manual does not show a connection between 3 and 5 whilst the ETM shows a connection but on the diagnostic half not the loopback half it would seem that in normal operation both ECU pins 18 and 31 are set to ground. I just discovered the correct reference for pins is as follows:- female pins male pins
5 3 1 1 3 5 4 2 2 4 looking at the ends; they match up when put together, Honest! :-)
The only other piece of information I have gleaned from the ISO/SAE specs is that the L line input resistance to ground is not less than 5 Kohm even if ecu not in operation, and apart from initialisation it should idle in logic state 1 (about 8 1/2 to 12 volts). This would suggest that the L line should not ever be tied to ground, making it pin
9 on the ecu and my pin 1 (officially 4 ) on the diagnostic socket.