P2B22 code meaning
Hybrid/EV Electronics Coolant Temperature Sensor B Circuit Low
Powertrain system Generic code P2Bxx codes Check engine light
What P2B22 means
P2B22 says the signal voltage of electronics coolant sensor B has fallen below its valid band. Since these sensors are NTC thermistors, a low voltage would mean an absurdly hot coolant, so the usual explanation is a signal wire touching ground, moisture bridging the connector or an internally shorted element. No manufacturer documents P2B22 publicly; NTN-SNR's catalogue calls it a too-small signal of sensor B. GM's 2019 HPC2 table shows typical numbers for the matching sensor A code P0CF0: below 4 % of the 5 V reference (0.2 V) for 4 s within 5 s, with more than 10.2 V supply, Type B. CARB requires such out-of-range checks on inverter cooling inputs. Because a hot value is taken seriously at first, the pump runs harder and power can be limited. P2B23 is the opposite case.
P2B22 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2B22
- Warning lamp or hybrid system message
- Electronics coolant pump and fans running at high output
- Reduced electric drive or charging power
Common causes of P2B22
- Most likelySensor B signal wire chafed through and shorted to ground
- PossibleWater or coolant in the sensor connector
- PossibleInternally shorted sensor element
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hybrid electronics coolant temp sensor bWiring harnessHybrid control module
What each part of P2B22 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| 22 | The exact fault in that area. |
What to do next
- Note P2B22 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 P2B22
What does P2B22 mean?
P2B22 means "Hybrid/EV Electronics Coolant Temperature Sensor B Circuit Low". P2B22 says the signal voltage of electronics coolant sensor B has fallen below its valid band. It is a generic code, so it means the same on every make.
Is it safe to drive with P2B22?
Drive gently and only to a workshop. With P2B22 the car can go into limp mode (reduced power) to protect itself.
Will P2B22 fail an emissions test?
Yes, it can. P2B22 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2B22 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. This is a job for a workshop.
Will P2B22 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.