Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Oldsmobile >> 1994 >> Bravada >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Electronic Transmission >> Self-Diagnostic System >> Diagnostic Procedure >> Diagnostic Procedure

Diagnostic Procedure

  1. Ensure all non-controlled systems not related to engine or transmission control system are operating properly. DO NOT  proceed with testing unless all other non-controlled system problems are repaired.
  2. ALWAYS begin system diagnosis with checking diagnostic circuit or system. On gasoline vehicles, see DIAGNOSTIC CIRCUIT CHECK in BASIC TESTING article in this section. The diagnostic circuit or system check determines if computer-controlled system is working properly. If trouble codes are displayed (other than Code 12), determine if codes are hard or intermittent trouble codes.
  3. A hard code is one which is present while working on vehicle, and problem still exists. Hard codes will cause the Malfunction Indicator Light (MIL) to come on.
    NOTE: SERVICE ENGINE SOON light, located on instrument cluster, is also referred to as the Malfunction Indicator Light (MIL).
  4. An intermittent code is one which does not reset itself and is NOT present while working on vehicle. Intermittent codes are often caused by loose connections. The MIL will go out 10 seconds after fault goes away. For intermittent diagnosis procedures, see the TESTS W/O CODES article in this section.
scientia non olet · About Mike's Workshop Manuals