What it means
The ECM detects a circuit high fault on the drive motor inverter temperature sensor f 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
The inverter converts battery power into the electrical current that drives the motor, and temperature sensor F monitors part of that inverter. The ECM monitors the sensor F signal circuit and sets this code when the signal is higher than its usable range. The resulting temperature reading cannot be trusted for inverter control and protection.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Save freeze-frame data and scan for related inverter codes to identify operating conditions and whether the fault is limited to sensor F.
- With the vehicle safely powered down, inspect the sensor F connector and accessible harness for an unplugged connector, broken wire, corrosion, or a signal wire touching battery positive.
- Check live data for sensor F and compare it with other inverter temperature readings; a fixed or implausibly high value supports a circuit fault.
- Using the manufacturer’s wiring information, have a qualified technician check the sensor F signal for an open circuit or short to power and inspect connector terminal contact.
- If the harness and terminals are sound, test the sensor F element against the manufacturer’s specification to determine whether it is open.
Common fixes
- Reconnect and secure a loose sensor F connector.
- Repair a damaged sensor F signal wire that is shorted to power or open.
- Repair corroded or poorly contacting connector terminals.
- Replace sensor F if testing confirms an open sensor, then clear the code and verify its live reading.
Can I keep driving?
Keep driving to a minimum and avoid high loads, since the inverter may reduce torque or enter limp mode when it cannot use sensor F temperature data. Stop safely and arrange recovery if the vehicle loses substantial power or displays a shutdown 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.