B0342 code meaning
HVAC Heated Seat Passenger Circuit
What B0342 means
No accessible J2012 list or manufacturer source mentions B0342; it matches B0337 in substance. As with the driver side, the HVAC prefix implies a climate module that also drives the passenger seat heater. In Saab's 9-3 that module reads a right seat temperature sensor too: B2172 02 below 0.2 V or B2173 05 above 4.8 V (tested only while the cabin is warmer than −10 °C) shuts the right heater down, while B2434 06 flags an open or grounded heater output. US5229579A puts a thermistor next to the heating element so the controller can regulate and spot faults. A failed sensor can therefore disable a heating mat that is itself intact.
B0342 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0342
- Passenger seat heating switches off immediately
- Passenger seat stays cold
Common causes of B0342
- Most likelyRight seat temperature sensor open or shorted
- PossiblePassenger heating mat broken
- PossibleConnector under the passenger seat loose
- Less likelyClimate module seat heater driver or sensor input faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Passenger seat heaterHeated seat module
What each part of B0342 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). |
| 42 | The exact fault in that area. |
What to do next
- Note B0342 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 B0342
What does B0342 mean?
B0342 means "HVAC Heated Seat Passenger Circuit". No accessible J2012 list or manufacturer source mentions B0342; it matches B0337 in substance. It is a generic code, so it means the same on every make.
Is it safe to drive with B0342?
B0342 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0342 fail an emissions test?
B0342 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 B0342 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0342 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.