What it means
The ECM detects a intermittent/erratic 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 provides a temperature signal used to manage electrical power through the generator inverter. The module monitors that signal for stability and sets this code when it becomes intermittent or erratic, rather than consistently failing high or low. A loose sensor B connector, poor ground reference, or vibration-sensitive contact can make the reading unreliable and trigger power limits.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
Symptoms
- Hybrid/EV system warning light on
- Power may be reduced if the inverter temperature reading becomes unreliable
How to diagnose it
- Save freeze-frame data and review sensor B's temperature history and related inverter codes to identify when the signal became erratic.
- Inspect sensor B's connector for incomplete seating, damaged locks, corrosion, or contamination.
- Examine the sensor B harness and ground reference for chafing, looseness, or routing that could let vibration disturb the connection.
- Monitor sensor B live data while gently checking the accessible harness and connector for signal dropouts, following safe service procedures.
- If the fault persists, test the sensor B circuit, ground reference, and sensor response against the manufacturer's specification.
Common fixes
- Reseat and secure the sensor B connector.
- Clean or replace corroded or damaged sensor B terminals.
- Repair an intermittent wire or ground connection in the sensor B circuit.
- Replace sensor B if its signal remains erratic with sound wiring and connections.
Can I keep driving?
Avoid hard acceleration, towing, or long trips if power is reduced, because an unstable sensor B reading can cause the system to limit inverter output. Stop if the vehicle loses substantial power or displays a high-voltage warning.
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.