This article describes how to read the engine error codes on General Motors vehicles that use the old OBD-1 system. The OBD-1 uses a 12 pin Data Link Connector located somewhere at the driverside of the dashboard. You need no scanner or special tool to read the error codes. You simply need to do the following…
- Turn off the ignition
- Locate the OBD Data Link Connector and use a wire to connect the Ports B and A
- Turn on the ignition
- Count the flashes of the „Service Engine Soon“ lamp (ex. flash, flash, pause, flash means code 21)
