Retrieving Codes
NOTE:
Codes can also be retrieved using a Scan tester. Diagnostic connector may also be referred to as ALDL test lead.
- Code retrieval starts with the DIAGNOSTIC CIRCUIT CHECK. The CHECK ENGINE light will come on when ignition is on and engine is not running. When engine is started, CHECK ENGINE light should go off. If light remains on while engine is running, a trouble code is present.
- If light did not come on with key on and engine off, inspect CHECK ENGINE light circuit before continuing. If CHECK ENGINE light failed to operate, See DIAGNOSTIC CIRCUIT CHECK. Circuit checks are located within test charts.
- To retrieve codes, install jumper wire between ALDL diagnostic leads. See Fig 1 . Turn ignition on. Count number of flashes from CHECK ENGINE light. A Code 12 is identified by a flash, pause and flash, flash. A long pause will occur. Code 12 will repeat 3 times. See Fig 2 . Each additional code will flash 3 times starting with lowest code to the highest number code. Once all codes are displayed, codes will repeat.
- If system is operating properly (with no codes), a Code 12 should exist with ignition on and engine off. This indicates the diagnostic system is capable of storing codes. After codes are retrieved, remove jumper wire from diagnostic leads to exit diagnostic mode.