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Abuse
11-17-2012, 10:48 PM
Ok, my check engine light is on on my 95 240 and I figured since no one does OBD 1 diagnostics I would just check the code myself. From what I have looked up is you turn the screw on the back of the ECU to diagnostic mode, put the key to the on position, then either the check engine light or the light on the back of the ECU flash the code pattern. Now I don't know if there is another step I'm missing but when I turn the screw to diag mode and turn the key to on, the check engine light turns off and the red LED on the ECU doesn't turn on or flash any solutions?

fliprayzin240sx
11-17-2012, 11:01 PM
No, put your key in the iginition, turn the key to ON (without starting the car), turn the screw on the back of the ECU clockwise, hold it there for 2 seconds or so, turn it back counterclock wise, and your check engine light/LED inside the ECU will start blinking in patterns. The long patterns are the first digit/tens number and the quick ones will be your 2nd digit/single numbers. So 3 long ones, then 4 quick ones = 34.

Once you get the codes, turn the screw all the way again, then back to take it out of diagnostic mode and reset the codes. Start the car, if your CEL comes back on, then you have to fix the issue.