Retrieving Codes (Non-Scan)

1994 Chevrolet Lumina BaseSECTION Retrieving Codes (Non-Scan)
NOTE: On models using a 12-terminal DLC (previously referred to as the ALDL), if a wire is present at terminal "B", inserting a jumper wire into test and ground terminals of DLC with engine running will cause fuel injected vehicles to enter field service mode. Flashes of SERVICE ENGINE SOON light will not indicate codes if this is done. See FIELD SERVICE MODE CHECK in BASIC TESTING article in this section. On models not using a 12-terminal DLC or not having a wire present in terminal "B", codes must be retrieved using a hand-held scan tester.
DATA LINK CONNECTOR (DLC) TEST TERMINALS

Application Ground/Test
12-Pin DLC (1)
(1) Tech 1 scan tester required to activate output/field service mode.
  1. Turn ignition on. DO NOT  start engine. SERVICE ENGINE SOON light should glow. Locate DLC attached to control module wiring harness. Most DLC's are located under dash on driver side of vehicle. For exact location of DLC, see COMPONENT LOCATIONS in the SYSTEM/COMPONENT TESTS - 3.4L article in this section. Insert jumper wire from terminal "B" (diagnostic test terminal) to terminal "A" (ground) of DLC. See Fig 1 .
  2. 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 this section. To exit diagnostic mode, turn ignition off and remove jumper wire from DLC connector.
Fig 1: ALDL/DLC 12-Pin Connector Terminal ID (3.4L)
G90B01199Courtesy of GENERAL MOTORS CORP.
RENDER: 1.0x

NO RELATED

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

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