DTC B2585: Parking Lamp Control Circuit Malfunction: 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. If other Automatic Lighting Control (ALC) DTCs exist, repair DTCs before continuing with diagnosis. If no other ALC DTCs are present, go to next step.
  3. Turn headlight switch to PARK position. If parking lights come on, go to next step. If parking lights do not come on, go to step  5 .
  4. Connect scan tool and read PARK LAMP input. Turn headlight switch to PARK and OFF several times. If BCM input for PARK LAMP toggles, go to step  11 . If BCM input for PARK LAMP does not toggle, go to step.
  5. Repair parking lights circuit. See appropriate wiring diagram in EXTERIOR LIGHTS. After repairs, go to BCM DIAGNOSTIC SYSTEM CHECK  under SYSTEM TESTS.
  6. Disconnect right hand instrument panel fuse block connector C1. Disconnect BCM connector C2. Using DVOM, measure resistance of Brown wire between BCM connector C2 terminal B8 and right hand instrument panel fuse block connector C1 terminal B12. See Figure . See WIRING DIAGRAMS  . If reading is less than 2 ohms, go to next step. If reading is greater than 2 ohms, go to step  8 .
  7. Using DVOM, measure resistance between right hand instrument panel fuse block connector C1 terminal B12 (Brown wire) and ground. If no resistance is indicated (infinite), go to step  10 . If any resistance is indicated, go to step  9 .
  8. Repair open in Brown wire between BCM and right hand underhood fuse block. After repairs, go to step  11 .
  9. Repair short to ground in Brown wire between BCM and right hand underhood fuse block. After repairs, go to step  11 .
  10. Replace BCM. See BODY CONTROL MODULE  under REMOVAL & INSTALLATION. After repairs, go to next step.
  11. Using scan tool, clear DTCs. Go to BCM 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.
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  • You are not confident in the next step or safety outcome.