What it means
The ECM detects a circuit fault on the generator inverter temperature sensor b circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Temperature sensor B monitors temperature in the generator inverter, which manages electrical power from the motor-generator. The control module checks the sensor B circuit so it can use that temperature in hybrid-system control. This code indicates a circuit fault has made the reading unreliable, and the system may reduce power to protect the inverter.
Common causes
Most likely first.
- Sensor failed
- Wiring or connector fault
Symptoms
- Hybrid/EV system warning light on
- Power may be reduced if the inverter temperature cannot be monitored reliably
How to diagnose it
- Save freeze-frame data and read generator inverter temperature sensor B data alongside related inverter or hybrid-system codes.
- With the vehicle powered down according to service information, inspect sensor B's connector and harness for loose connections, corrosion, heat damage, or chafing.
- Check that the sensor B connector is seated and that its pins are not bent, pushed back, or contaminated.
- Test sensor B's circuit and sensor response using the manufacturer's wiring diagram and specification to distinguish a sensor fault from a wiring fault.
- If the sensor and wiring test correctly, check the module's circuit connections and input using the manufacturer's procedure.
Common fixes
- Reconnect or repair loose, damaged, or corroded sensor B wiring and terminals.
- Repair a damaged section of the sensor B harness.
- Replace generator inverter temperature sensor B if its readings or circuit test fail the manufacturer's specification.
- Repair the module connection or input only if testing confirms it is at fault.
Can I keep driving?
If the vehicle has reduced power or an inverter warning, avoid hard acceleration, towing, and long trips; the system may be unable to assess generator inverter temperature reliably. Stop driving if power loss is severe or a high-voltage warning appears.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.