Your best bet is to use a multimeter with a %Duty Cycle scale. If a code is set it will be a very accurate multiple of 10% with ignition on, engine off.

So, there are only ten codes. Use the duty cycle meter on pin 3 of the round connector on the ignition module and ground the other lead. The ignition module is on the left fenderwell.

Give us the %code and we will decipher it for you.

There are some guys who say that they have successfully done this measurement with a voltmeter. Since I have my $29.95 special meter with duty cycle range, I haven't tried that trick. If you don't have a duty cycle meter you might do a search to get the information.

Good luck,