Hello I will help you with your question,
There are a pair of green "DCheck" connectors under the dash on the drivers side. This is right hand drive? Connect them together and turn the key to run. The check engine light should blink a series of codes with a long blink followed by two short blinks being a "12"
Post the codes back here and I will help you determine the next action to take.
This is not a good thing and usually means that the computer has had it. Be sure that the pair of black connectors is not connected. They are near the green connectors.
If you confirm that the connectors are correct and that the powers and grounds for the computer are correct I would spend the diagnosis money to have someone with a select monitor check one last time before you bite the bullet and put a computer in ti. They are not inexpensive so it would be worth the money to be sure
Please let me know what I can do to help you with this
I was sleeping so I gues the system dosen't care if I get any rest!!
If you have a voltmeter check pins 2 and 13 in connector B48 for battery voltage and pins 11,22,21 in the same connector for ground. Check pin 14 in connector F47 for ground as well.
There is a small possibility that the ceheck engine light control wire is shorted to ground. This is found at pin #19 in connector F47
The connector views and location of the ECU are in the diagrams below
I don't have interchange information for the different years but you can check the numbers on the case to see if the part numbers match.
Do you have any issues other than the light being on? If not you can try resetting the system by removing the negative battery cable for an hour with the key in the run position then reconnect the cable. It may allow the computer to reset.
This does sound like the computer has packed it in and is operating in failure mode which will allow you to run the engine enough to get to a place of safety and service. It will not run indefinitely though.
I would spend the diagnostic money to have a shop with a Select Monitor try to communicate with the computer. Call ahead and ask specifically if they have a Select Monitior as the aftermarket tools most shops have will not comunicate even if the computer was working properly.
I didn't ask if this is an automatic trans or a manual but the break point on the computer is threefold if you have an auto, before 7/92, between 8/92 and 9/92 and after 9/92 so if you have an auto trans it is not likely that the '92 is going to run your car.
If you search at car-part.com you can see what yards in your area have computers.
As always let me know what I can do to help you with this
I don't think my information and memory was that faulty but I am glad you were able to get the codes.
A code 12 is a faulty starter switch which is likely not a "real" code but was induced while you were trying to read the codes.
Code 13 is the cam angle sensor. This is a high failure item and you can get the cam and crank sensors as a set from you dealer for less than either alone
CHECK CAM ANGLE SENSOR
CHECK HARNESS BETWEEN ECU AND CAM ANGLE SENSOR
Code 21 is the coolant temp sensor (another high failure item)
CHECK ECU VOLTAGE With ignition "ON," measure voltage between ECU connector terminal (B48)7 and ground. It should measure 0.6 - 4.5V .CHECK COOLANT TEMPERATURE SENSOR
CHECK HARNESS BETWEEN ECU AND COOLANT SENSOR
I am sorry if I offered confusing advice, that is surely not my intent.
The cam sensors is on the front of the head and the crank sensor is in the center of the block just above the balancer. Makes them easy to get to.
If you have a code for the coolant temp sensor (code 21) that is likely why your fans are running all the time, if it is shorted or the signal wire is shorted to ground the computer thinks the engine is hot so it turns the fans on.
Let me know what information you need and I will be happy to provide it
The diagram was posted above, it is the MPFI unit next to the AT control unit if you have an Auto trans
Sorry if this was not clear