Hello and welcome.
To read codes, you will need to jumper the diagnostic connector uneder the dash. Turn key off, install jumper wire between terminal A and B.
Turn key on and count the flashing check engine light.
Codes are flashed like this..."Flash...Flash-Flash. This is code 12.
The ECM will cause the "Service Engine Soon" light to flash Code 12, indicating that the ECM diagnostics are working. Code 12 will flash three (3) times, followed by any other trouble codes stored in memory. Each additional code will flash three (3) times, starting with the lowest code, and then start over again with Code 12. If there are no other codes, Code 12 will flash until the diagnostic jumper is disconnected or the engine is started.
Example: An error Code 13 will be: 12,12,12,13,13,13,12,12,12, any more Codes