B0283 code meaning
Rear Defogger Relay Control Circuit
What B0283 means
B0283 is not in any publicly available J2012 list; it is documented by Saab/GM, where it means the heated rear window relay, not a blower. In the Saab 9-3 (2003–2012) the rear electrical centre sets B0283 01 when the relay output exceeds 6 V with heating on, and B0283 06 when it stays below 6 V (open or grounded line). The GM-built Saab 9-5 and 9-4X of 2011 run the test in the climate module at 9–16 V: 02 means a grounded relay control line and the grid heats nonstop, 05 means open or short to voltage and the grid stays cold; a history code clears after 50 ignition cycles. As US4673797A shows, such relays are usually timed and drop out after a set period. Front blower faults belong to B0181/B0186; the heating grid itself is B0950.
B0283 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0283
- Heated rear window does not work when switched on
- Rear window heats continuously and cannot be switched off
- Battery drained if the grid keeps heating
Common causes of B0283
- Most likelyRear window heater relay with open coil or welded contacts
- PossibleRelay control wire open, grounded or shorted to battery voltage
- PossiblePoor ground or corroded socket at the relay
- Less likelyOutput stage of the climate or electrical centre module faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rear defrost relayRear window heating elementHvac control module
What each part of B0283 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). |
| 83 | The exact fault in that area. |
What to do next
- Note B0283 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 B0283
What does B0283 mean?
B0283 means "Rear Defogger Relay Control Circuit". B0283 is not in any publicly available J2012 list; it is documented by Saab/GM, where it means the heated rear window relay, not a blower. It is a generic code, so it means the same on every make.
Is it safe to drive with B0283?
B0283 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0283 fail an emissions test?
B0283 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 B0283 to fix?
Difficulty: easy. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0283 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.