Retrieving Codes (Non-Scan)
- Turn ignition on. DO NOT start engine. SERVICE ENGINE SOON light should glow. Locate DLC attached to control module wiring harness. Insert jumper wire from terminal "B" (diagnostic test terminal) to terminal "A" (ground) of DLC. See Fig 1
.
- SERVICE ENGINE SOON light should begin to flash codes. Each code will be repeated 3 times. If codes are not flashed or SERVICE ENGINE SOON light does not glow, perform DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING
article in the ENGINE PERFORMANCE section. To exit diagnostic mode, turn ignition off and remove jumper wire from DLC connector.
Courtesy of GENERAL MOTORS CORP.
Courtesy of GENERAL MOTORS CORP.