B0250 code meaning
HVAC Air Temperature Internal Sensor Circuit
What B0250 means
None of the publicly available J2012 lists contain B0250. On the Saab 9-3 the number marks an actuator fault instead: B0250 06 means the floor door motor circuit is open or grounded, which upsets air distribution, while B0251 01 is the B+ short. Taken by its title, the code is about the cabin temperature sensor, which also has the code B0160. These sensors are NTC elements whose resistance falls as they warm, as HELLA documents for its own air temperature sensor. To measure real cabin air rather than still air behind the dash, TGK's patent US6622924B2 pulls air past the thermistor with a small brushless fan whose rotation is reported on its own pin. If the circuit fails, automatic climate control works with a substitute value and the cabin ends up too warm or too cold.
B0250 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 B0250
- Automatic climate control holds the wrong cabin temperature
- Blower speed and outlet temperature no longer adapt as the cabin warms up
Common causes of B0250
- Most likelySensor plug or wiring behind the dashboard open or shorted to ground
- PossibleNTC element in the sensor damaged
- Less likelyAspirator fan seized or its intake grille blocked, so the reading lags behind cabin temperature
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cabin air temperature sensorHvac control module
What each part of B0250 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). |
| 50 | The exact fault in that area. |
What to do next
- Note B0250 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 B0250
What does B0250 mean?
B0250 means "HVAC Air Temperature Internal Sensor Circuit". None of the publicly available J2012 lists contain B0250. It is a generic code, so it means the same on every make.
Is it safe to drive with B0250?
B0250 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0250 fail an emissions test?
B0250 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 B0250 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 B0250 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.