Reading trouble codes

[LMP]

For GM cars equipped with OBD1 diagnostic system ( before 96 for most), one can read a lot of trouble codes by reading the flashes of the CHECK ENGINE LIGHT . THis is done by switching the computer in the diagostic mode in the following way:
- remove the plastic cap from the diagnostic plug (near the parking brake release handle)
- connect together the TOP RIGHTEST connectors of the plug - known as B and A. Use a small solid wire inserted at both ends in A and B.
- turn the ignition key to RUN: do not start the engine

The CHECK ENGINE LIGHT will start flashing code 12 3 times...this is one flash - then pause - then 2 short flashes, pause and repeat twice. THis indicates the diagnostic mode in operative.
THen if any trouvle codes are stored, they will flash in sequence, like 53 will be 5 short flshes, pause, then 3 short flashes, then next code.
WHen finished, code 12 will flash again.

When you are through, remove the jumper wire.

If one wants the meaning of the codes, I can help...well within a few hours, I will post them at www.avigex.ca/codes