What it means
The ECM detects a high 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 sends a temperature signal to the control module for managing hybrid-system operation. This code sets when the signal is higher than the circuit’s expected electrical range, as may occur with a signal short to battery voltage or an open sensor circuit.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid/EV system warning light on
- Power may be reduced if the inverter temperature cannot be monitored reliably
How to diagnose it
- Record freeze-frame data and compare sensor B’s live reading with the other inverter temperature sensors for a fixed or implausibly high value.
- With the system safely powered down according to service information, inspect sensor B’s connector for corrosion, loose fit, or damaged pins.
- Inspect the signal wire for damage or contact with a battery-positive feed.
- Check for an open in the sensor B circuit and verify connector terminal contact using the manufacturer’s procedure.
- Test sensor B against the manufacturer’s specification to confirm whether the sensor is open internally.
Common fixes
- Repair loose, corroded, or damaged sensor B connector terminals.
- Repair the signal wire if it is shorted to battery voltage or otherwise damaged.
- Replace sensor B if it has an internal open or fails the specified test.
- Repair a confirmed open or connection fault between sensor B and the control module.
Can I keep driving?
Keep trips short and avoid heavy loads because unreliable inverter temperature feedback can prompt the hybrid system to limit power. Stop safely if the warning comes with overheating signs or a substantial 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.