DTC B2958: Security System Sensor Data Circuit High: 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 THEFT DETERRENT DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS. Go to next step.
  2. Disconnect BCM connector C2. Disconnect Passlock(R) sensor connector. Using DVOM, measure voltage between Passlock(R) terminal "A" (Yellow wire) and ground. See WIRING DIAGRAMS  . If zero volts is indicated, go to next step . If any voltage is indicated, go to step  6 .
  3. Repair short to voltage in Yellow wire between BCM and Passlock(R) cylinder. After repairs, go to step  13 .
  4. Using DVOM, measure resistance of Yellow wire between BCM and Passlock(R) sensor. If reading is less than 2 ohms, go to step  6 . If reading is greater than 2 ohms, go to next step.
  5. Repair open or high resistance in Yellow wire between BCM and Passlock(R) sensor. After repairs, go to step  13 .
  6. Check for poor connection at BCM connector C2. If poor connection is found, go to next step. If connections are okay, go to step  8 .
  7. Repair poor connection at BCM connector C2. After repairs, go to step  13 .
  8. Check for poor connection at Passlock(R) connector terminal "A" (Yellow wire). If poor connection is found, go to step  10 . If connections are okay, go to next step.
  9. Disconnect BCM connector C2. Set DVOM to measure DC voltage and back probe between connector C2 terminal B6 (Yellow wire) and ground. If reading is 6 volts, go to step  11 . If reading is other than 6 volts, go to step  12 .
  10. Repair poor connection at Passlock(R) connector terminal "A" (Yellow wire). After repairs, go to step  13 .
  11. Replace Passlock(R) sensor. See IGNITION SWITCH  under REMOVAL & INSTALLATION. After repairs, go to step  13 .
  12. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs, go to next step.
  13. Using scan tool, clear DTCs. Go to THEFT DETERRENT DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
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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.