2002 Cadillac DeVille BaseFACTORY OEM SERVICE PROCEDURE

Lighting DTCS

LIGHTING DIAGNOSTIC TROUBLE CODE (DTC) LIST

DTC Description
DTC B1438 54V VF Display Supply Circuit Current Draw
DTC B2556 Interior Lamp Rheostat
DTC B2641 Twilight Pot Voltage
DTC B2646 Sunload Sensor Output
Factory Service Tools

Use the Manual With the Right Hardware

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

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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.