Body, generic

B0990 Body Control Module Internal Fault

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

For B0990 no public evidence exists, be it in J2012 lists or in carmaker or NHTSA papers. The title describes a self-detected failure inside the body control module. GM-era Saab models report this as B1000 or B101D: on the 2011 Saab 9-5 the module runs its internal test at every power-up, refuses further inputs on a fault and clears a history entry after 50 fault-free ignition cycles; a module should only be replaced if the code is current. The 9-3 BCM stores B1000 37 for an internal timeout, and its column module logs B3985 when the immobiliser code cannot be written into the BCM. TI lists open-load and short detection and fail-safe behaviour among the core BCM functions. Rule out supply and ground faults before replacing it.

Likely causes

Poor supply voltage or ground at the module
Moisture or corrosion inside the module
Corrupted or outdated module software
Internal electronic failure of the module

Symptoms

  • Several body functions fail at once, such as lights, locks or wipers
  • Car will not start if the immobiliser data cannot be read
  • Code stored only as history without any noticeable effect

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,200
Time1–4 h

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

Parts involved

body control module

Related codes

B0980

References: saabwisonline.com, saabwisonline.com, saabwisonline.com, saabwisonline.com.