I have been researching this for a while and have found several informative sites but nothing specific. I know my car has a computer PCM and I know there is a way to read what my car's computer is doing. I went to one site and built a LED, switch, and cable to read codes but dont know how to hook it up to my connector.


Any body have any ideas where to go to for more information?



Thanks Anthony

The LED box allows you to draw codes from the diagnostic connector near the battery next to the heater control valve. These codes are for subsystems only such as SRS, ABS, and CCU. The engine codes are drawn from the EZL ignition module mounted on the left inner fender well. The way that codes are drawn from there is by measuring duty cycle from pin 3 of that connector to ground.

I'm sure that the dealers had/have a fancy analyzer to connect to the EZL diag connector, but there are only 10 or less codes that can be drawn from there. Each code is indicated by a solid duty cycle that is a multiple of ten. If the duty cycle is not stable then there is no code present.

Have a great day,

Do I short a couple of pins to get those codes? Or does it constantly send a signal?

Any ideas?


Thanks
Anthony

124.026 chassis will have flash code if it is Cal emissions. If Cal, pin #3 will get you engine Flash codes.

I can only assume that by "those codes" you mean pin 3 of the EZL. You don't short anything, you simply use a duty cycle meter from ground to pin 3 and read the duty cycle. If it is a solid duty cycle number without drifting it will be a multiple of ten. 10% will indicate one code 20% another and so forth.

If you have a check engine light you should see a solid multiple of 10. Tell us what it is and we will try to look it up for you.

Good luck,

Larry,

I have the same problem.

Sorry for being uneducated about these things, but what am I measuring resistance or amps at 10V?

If its AMPS it might me a 7

I am using an analog meter.

Thanks,

__________________
John

1995 E320 - 115kmi+ Smoke Silver/Cream (Wife's Wagon)
1989 260E - 195kmi+ Black/Grey (My Panther)
1984 300D - 242kmi+ Black/Palomino (Retired)