AL52818

I just used the paper clip trick to extract DTC's for my 95 Chevy Tahoe. Can anyone tell me how to read the following flash sequence: 1 short, 1 long, 2 shorts. Is this DTC 13 ? Any help greatly appreciated.

rb1

to read DTC's the ECM will flash a 12 3 times before any codes will flash. Usually 1 short followed by 2 short flashes.

AL52818

RB Thanks for the reply. Should have included in my original post tthat I do get the initial DTC 12 first, then this is followed by the 1 short, 1 long, then 2 shorts that I described originally.

ratinfested

If the 1-long was a pause then you have 12 all over again which means there are no codes stored.

2000CAYukon

Actually, if the 1-long is a pause, it could be Code 21. I went out to my truck at lunch time and set code 42 by disconnecting the EST wire. After juming pins A and B I got:

flash, pause, flash, flash, long pause (Code 12),
flash, pause, flash, flash, long pause (Code 12),
flash, pause, flash, flash, long pause (Code 12),
flash, flash, flash, flash, pause, flash, flash, long pause (Code 42),
Code 42 repeated.

After the long pause will be the first digit, then a short pause, and then the last digit.

//2000CAYukon