Body, generic

B0860 License Plate Lamp Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

B0860 is not traceable in public J2012 extracts, and no manufacturer or regulator text refers to it. The title describes the lamp lighting the rear number plate. GM's 2011 Saab 9-5 switches it through the body control module whenever parking or dipped lights are selected, logging B3883 02 for a grounded and B3883 04 for an open feed. The older Saab 9-3 uses the same number in its rear electrical centre with stated limits: an open circuit below 20 mA, a short once over 3.5 A flows for longer than 10 ms, which also cuts the output. FMVSS 108 defines the licence plate lamp and requires it on every car. A dark plate light is not a driving hazard, but it is a roadworthiness defect that police checks can pick up.

Likely causes

Plate lamp bulb burnt out
Water in the lamp housing corroding contacts
Wire break in the boot lid hinge area
Lamp output of the body or rear module faulty

Symptoms

  • Number plate not illuminated with lights on
  • Lamp warning in the display
  • Plate lamp stays on permanently in some short-circuit cases

Repair estimate

DifficultyEasyDIY possible
Parts and labour€5–150
Time0.2–1 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

license plate lampbody control module

Related codes

B0239B0850

References: saabwisonline.com, saabwisonline.com, saabwisonline.com, law.cornell.edu.