What it means
The ECM detects a range/performance 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
Generator inverter temperature sensor B measures temperature at one point in the generator inverter, and the control module uses its signal to manage hybrid-system operation. This code sets when sensor B’s reading is outside the expected range or does not change plausibly as conditions change, so the module cannot rely on it for temperature control.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Hybrid/EV system warning light on
- Power may be reduced if the inverter temperature reading is implausible
How to diagnose it
- Record freeze-frame data and compare sensor B’s live reading with the other inverter temperature sensors and ambient temperature to see whether it is implausible.
- With the system safely powered down according to the vehicle’s service information, inspect sensor B’s mounting and connector for displacement, damage, moisture, or corrosion.
- Check the sensor B harness for rubbing, tension, or heat damage that could disturb the signal.
- Monitor sensor B while inverter temperature changes and look for a reading that is stuck, erratic, or inconsistent with the other sensors.
- Test sensor B and its circuit against the manufacturer’s specification to distinguish a drifting sensor from a wiring or module-side fault.
Common fixes
- Secure sensor B in its specified position.
- Repair damaged or poorly seated sensor B wiring or connector terminals.
- Replace sensor B if its output is outside the manufacturer’s specification.
- Repair a confirmed fault in the circuit between sensor B and the control module.
Can I keep driving?
Limit driving and avoid demanding acceleration or heavy loads; the hybrid system may reduce power if it cannot trust the inverter temperature reading. Stop safely if a hybrid-system warning appears with overheating indications or a major loss of power.
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.