B0990 code meaning
Body Control Module Internal Fault
What B0990 means
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.
B0990 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0990
- 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
Common causes of B0990
- Most likelyPoor supply voltage or ground at the module
- PossibleMoisture or corrosion inside the module
- PossibleCorrupted or outdated module software
- Less likelyInternal electronic failure of the module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Body control module
What each part of B0990 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 90 | The exact fault in that area. |
What to do next
- Note B0990 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about B0990
What does B0990 mean?
B0990 means "Body Control Module Internal Fault". For B0990 no public evidence exists, be it in J2012 lists or in carmaker or NHTSA papers. It is a generic code, so it means the same on every make.
Is it safe to drive with B0990?
B0990 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0990 fail an emissions test?
B0990 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is B0990 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will B0990 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.