I have had my 1992 Royal Lounge Town Ace for over two years but have only recently noticed, just in front of the air filter,a small socket with a cap on it labelled 'Diagnosis'.Is this ever used,is it usable and what sort of readings is it likely to give
- (#8256) paul cavanagh (Wirral), 1 Feb 04 10:10
I'm assuming you have a petrol model if you have a diag socket, this is used to flash code the ECU on EFi models, don't touch it, unless you know how to get the flash codes out of it, and even if you do get the code out, you will need the flach code table to interpret them. This is used by garages & dealers to get the fault codes out of the ECU to aid in fault diagnosis.
Regards Rob.
- (#8256) Rob Drinkwater, 1 Feb 04 10:30
It's for Toyota use, to hook up to their diagnosis computer. Suspect any reading may not be any use without the computer.
- (#8256) Clive (Bristol), 1 Feb 04 10:33
Thank you for your very prompt reply.I should have mentioned it is a Turbo Diesel Auto.
- (#8256) Paul Cavanagh, 1 Feb 04 11:48
does it have ABS or TEMS? Pre- or post- '92 facelift? It's not normal for the diesel to have a diagnostic socket. Has the engine been changed perhaps?
- (#8256) david miller, 1 Feb 04 13:42
It has TEMS and is post facelift.As far as i'm aware there are no engine changes.
- (#8256) Paul Cavanagh, 2 Feb 04 07:48
Do you have cruise controll?
- (#8256) dave Bright, 2 Feb 04 08:41
Thanks for all the trouble you'r taking.No it does'nt have cruise control.I can't think of anything else that is different.Would garages other than Toyota be able to use it.
- (#8256) Paul Cavanagh, 2 Feb 04 10:12
I had a dig around and could not find any socket. I did find a female plug, round translucent, well as much as it can be in an engine compartment for 13 years, two wires to it one green other maybe white with black stripe. It was tucked under the edge of the engine bay, midway between the expansion tank and the earthing point infront of the air filter. Any ideas, there was no male plug to be seen and it only had 3 or 4 inches till it gets wrapped up in the loom?
- (#8256) Clive (Bristol), 2 Feb 04 10:47
clive,
i also found a female plug next to the air filter ? not sure what or where it is connected too
i had a good look thinking something was unpluged and could not find a male to connect it too
dennis
- (#8256) dennis, 2 Feb 04 11:43
I have been thinking that it maybe something to do with the automatic transmission, but I have been scanning the USA van manual electrics, and can find no sign of a diagnostic connector any where. My guess is that as the USA manual is for petrol engines not Diesel, it could be connected to that. Then It occurred to me that Diesel automatics have an EGR valve mounted in that area. So its possible that this is for connecting a test rig, maybe something simple like a lamp, to indicate if the EGR valve is operational?
- (#8256) dave Bright, 2 Feb 04 14:08
Simply, it'll allow some diagnostic modes of the TEMS system. Check in the Chiltons book, anyone with a copy.
The townie is too old to have digital diagnostics of any kind (like J1962), and Toyota always had a penchant for analogue breakout boxes. It'll just be a case od shorting the correct terminals out, or possibly connecting a lamp or voltmeter to other terminals, to measure a voltage change or blink code.
- (#8256) david miller, 2 Feb 04 14:46
Mr Miller on the ball again. Looks very much like the TEMS service connector, I will check with my meter tomorrow. It is used to check the steering sensor.
Chilterns only has a section on the Cressida and the TEMS test terminal is in a block with others. It goes like this
Place whels straight-ahead
Place jumper wire to short the terminals
Turn IGN to on, check both TEMS lights come on
Turn steering wheel 1/4 turn right and check right hand - righthand light should flash, left go out
return to straight ahead.
Then repeat turning left and lights should be reverse of above.
Of course this is where Dennis posts "But I haven't got TEMS".
Paul do you have TEMS and does the socket have two terminals?
- (#8256) Clive (Bristol), 2 Feb 04 17:57
i have looked more closely at the socket.it is about
3.5cms x2cms with a hinged lid.there are 18 terminals which have been packed with grease.having cleaned the inside of the lid i found there is a labelled diagram of the terminals (like the fuse box lid)as follows ;fp,w,e1,ox1,ab,opt,cco,te1,te2,cc2,t2,+b,vf1,vf2,ox2,ts,tt,ig1.yes there is a cable running from it to a wiring loom.i have tems.
- (#8256) Paul Cavanagh, 7 Feb 04 16:31
That's a standard, non- OBD2 Toyota diagnostic connector. I'll bet you've only got a couple of wires going to it, not the full set. Here's some that I know-
B+ 12v Battery
FP supply to fuel pump
IG1/- tacho pulses
E1 earth
W check engine light
TE1 test mode- short to ground to get blink codes
OX1 & 2 Lambda sensors
So you can negate FP and OX1,2 as not applicable to diesels. Some of the others might be connected...
- (#8256) david miller, 8 Feb 04 02:07