Body, generic

B0821 Right Headlamp High Beam Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

For B0821 there is no public trace in J2012 extracts, factory manuals or NHTSA files. The title describes the right main-beam circuit. Saab's 9-3 (type 9440) watches it under its own number B3866: open (04) when the lamp draws under 0.8 A with main beam on, overcurrent (0B) in the 7.9–30 A band; apart from the warning the module takes no action. Because high beam is only used on empty roads, a one-sided failure is often noticed late, mostly as a darker right verge. In GM's 2011 Saab 9-5, by contrast, a fault on the shared relay line (B2580 01) switches off both sides together. FMVSS 108 lists the beam switching device and the upper-beam indicator as required equipment. Left side: B0820.

Likely causes

Right high-beam bulb failed
Supply wire to the right headlamp open or shorted
Higher-wattage bulb fitted, triggering overcurrent
Main-beam output of the lighting module faulty

Symptoms

  • Right main beam stays dark, left one works
  • Lamp warning in the display when high beam is switched on

Repair estimate

DifficultyEasyDIY possible
Parts and labour€10–500
Time0.2–2 h

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

Parts involved

right high beam lampbody control module

Related codes

B0820B0811

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