DTC B2965: Key In Ignition Fault: Testing

1998 Oldsmobile Achieva 3.1 M, 4T40E/MN4SECTION Testing
WARNING: This page is about a different car, the 1999 Pontiac Grand Am and 1999 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: If circuit is shorted to ground, fuse will blow. Check fuse before performing diagnostics.
  1. Perform BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS. Go to next step.
  2. Locate connector C2 terminal B12 (Light Green wire) at BCM. See WIRING DIAGRAMS  . Remove key from ignition switch. Using DVOM, backprobe for voltage between terminal B12 and ground. If battery voltage is indicated, go to step  4 . If battery voltage is not indicated, go to next step.
  3. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs, go to BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
  4. Connect scan tool to Data Link Connector (DLC). Select BCM INPUTS and observe KEY IN IGNITION status. Connect fused jumper between ground and PCM connector C2 terminal B12. If KEY IN IGNITION status reads YES, go to next step. If KEY IN IGNITION status does not read YES, go to step  3 .
  5. Remove terminal B12 (Light Green wire) from BCM connector C2. Remove terminal "D" (Light Green wire) from connector C2 of ignition switch. Using DVOM, measure resistance of Light Green wire. If reading is less than 2 ohms, go to step  7 . If reading is greater than 2 ohms, go to next step.
  6. Repair open in Light Green wire between BCM and ignition switch. After repairs, go to step  11 .
  7. Remove connectors C1 and C2 from ignition switch. Using DVOM, measure resistance between connector C1 terminal "D" and connector C2 terminal "E" of ignition switch (switch side). See Fig 1 . Insert key into ignition switch. If reading is less than 2 ohms, go to step  9 . If reading is greater than 2 ohms, go to next step.
  8. Replace ignition switch. See appropriate ANALOG INSTRUMENT PANELS article. After repairs, go to step  11 .
  9. Disconnect splice pack at G202. G202 is located on the left side of the instrument panel. Using DVOM, measure resistance of Black/White wire between ignition switch connector C2 terminal "D" and splice pack terminal "D". If reading is less than 2 ohms, go to step  11 . If reading is greater than 2 ohms, go to next step.
  10. Repair open in Black/White wire between splice pack and ignition switch. After repairs, go to next step.
  11. Using scan tool, clear DTCs. Go to BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
Fig 1: Identifying Ignition Switch Connectors & Terminals (Connector Side)
G99J08618Courtesy of GENERAL MOTORS CORP.
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When to See a Mechanic

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

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.