When the computer (ECU) in your car detects a
problem with how the car is running it reports it by lighting up the yellow
engine light on your dash. Any Joe Schmoe can actually check what the
ECU is complaining about as long as they know how.
Instructions and pictures to find the 3rd and
4th Gen service connectors will be coming soon.
In order to get the code you'll need to find
the service connector. On the 5th Gens it's on the right hand side of
the centre console underneath a carpeted panel that just pops right out.
The connector looks like a telephone connector and is plugged into a blue
plastic piece that just serves as a holder. Unplug it and you'll see that
it has two sockets in it that lead to two wires.
You'll need a small piece of wire for this. Make
sure the car is off. Just connect the two ports in the service connector
together with the wire. After you've shorted the service connector, turn
the key in the ignition to the on position (you don't actually need to
start the car) and the yellow engine light will flash at you. There will
be a series of long flashes, short flashes, and then it will repeat itself.
Count the number of long flashes and short flashes and this will give
you the MIL code. 2 long flashes and 3 short flashes is code 23. Once
you've found the code, turn the key back to off and remove the wire from
the service connector. You can look up the code in the following table.