I have an Ex-Japan 4-door 16 valve EFI Suzuki Escudo 1993-model. My catalytic converter overheating warning light came on after clocking 62,500Kms way back in January this year. I have so far made additional 4,000Kms with the light on and no fuel consumption change. I'm still doing 10 Kms/litre in heavy traffic conditions in town.

I understand that in other vehicles this could mean that the "exhaust gas temperature sensor circuit" is open or shorted. To solve the problem you must access the sensor, which is normally, located under the passenger seat. To be more precise it is under the carpet over the catalytic converter!

But alas! After doing the donkey job of removing the seat and carpet, there was nothing. The harness goes past this area. Could you have an idea of the location if that is the case? There is also a sensor sticking out of the "Cat" right in the middle, could it be this one? Or is this just another oxygen sensor?

I have also been made to understand that this could also be an alert signal after some mileage (kilometerage) to prompt you to take the car to the dealer for service of certain items and this can be disable through a switch under the dash. Unfortunately I have been unable to locate this switch under the dash. I have also on several occasions tried to cancel the warning light by disconnecting the battery but with no success!

I don't have the OEM driver's or Workshop manual for reference, which has increased my agony and helplessness.

I think it is important to mention that in Kenya we still use leaded fuel and actually wonder whether this has not affected the sensors and the other emission controls. Are there any adjustments made to the ECU to factor the use of leaded fuel before exportation to such countries since I am not aware of any users with EFI engines complaining of premature failure in their systems because of this?

The other thing is my Test connector for fault code diagnosis has 5 terminals instead of the four found in most Suzukis. From the battery-end moving clockwise, the wires are coloured as follows:
1. Black
2. Blue/Red
3. Violet
4. Violet/Yellow
5. Blue/Yellow

1-2 and 3 are in a straight line and 2-3-4-5 form a square, You get what I mean? Haynes Manual with a four-pin connector indicates that terminals have the following functions in a clockwise order:

1. Duty check.
2. Diagnostic Test
3. Ground
4. Test switch

Can anyone explain to me the functions of the Duty check, Test switch and also the functions of Terminals 2-5 on my Zuki.

I would be most obliged if I were favored with appropriate answers to my woes.

Hello?
Anybody there?
Do you think the manufacturers could be of any assistance on this?
Any addresses please?

if it is the service light on the dash ... this can be disabled by removing the clip on square plastic plate located on the dash plastics under the steering wheel.and if you peer inside with a flashlight you will see a small 2 position switch
flick the switch over and the dash light will go off
i believe it is pre set to come on at a certain mileage to prompt for major service... cam belt etc
hope this helps

if it is the service light on the dash ... this can be disabled by removing the clip on square plastic plate located on the dash plastics under the steering wheel.and if you peer inside with a flashlight you will see a small 2 position switch
flick the switch over and the dash light will go off
i believe it is pre set to come on at a certain mileage to prompt for major service... cam belt etc
hope this helps

Or you can remove the left front speaker and reach in and flick the switch. Its a small switch so it might be hard to find. It does kind of sound like this is your problem.

Mike

I have gone through the whole harness under the dash with a fine comb but unfortunately that switch does not exist. Any more ideas?

its there
keep looking

Leaded fuel will cause problems with
the O2 sensor as well as the Cat, you
might be overheating the Cat and if this
were the case, and you still run leaded fuel
you might want to get a strait through pipe,
and the O2 sensors, good luck, depending
on the quantity of lead might need replacement
every few months, I don't know of any O2s that
work with Leaded fuel, tho there might be some
available in your country, as there has to be
other EFI vehicles driven there, what do they do for
fuel and O2 sensors

The number one on the four pin you have is for the duty cycle of you idle air controler that is set at the factory and should not be messed with, I think it is supposed to be at like 50% when warm, the number four might be for setting your timing? you short it out with one of the other pins (do not remeber what pin)and adjust your distrubitor to what the book say's lock it down and pull the shorting wire off.

if your worried about the 0₂ sensor causing the light to come on then buy a O₂simulator... i think Jegs or Summit have them... donno what you would do to get one but they are bound to be other places too...

best solution, remove the cat