1997 Buick Century CustomFACTORY OEM SERVICE PROCEDURE

DTC B0608, BCM Power MODING Error: Notes

BCM receives voltage inputs from 3 ignition signals. BCM receives voltage from IGN0 fuse (wake up signal) when ignition switch is in OFF/UNLOCK, RUN or START position. BCM receives voltage from PCM-BCM fuse (not asserted wake up; prevent vehicle sneak circuits) when ignition switch is in RUN or START position. BCM receives voltage from CRANK SIGNAL fuse (prevent vehicle sneak circuits) when ignition switch is in START position.

DTC B0608 will set when BCM detects any of the following conditions for more than 0.3 second: IGN1 is active and IGN0 is inactive; CRANK is active and IGN0 is inactive; or CRANK is active and IGN1 is inactive. No driver warning message will be displayed.

If conditions for malfunction no longer exist, history DTC will clear after 100 consecutive ignition cycles. DTC B0608 will also clear when conditions no longer exist or when scan tool is used to clear codes.

NOTE: If DTC B0608 is a history code, problem may be intermittent. Wiggle wires while performing the following test.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

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

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