What it means
The ECM detects a range/performance fault on the dc/dc converter 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
Temperature sensor F monitors heat at a point in the DC/DC converter, which converts high-voltage hybrid power to lower-voltage power. This range/performance code sets when its signal is present but does not track temperature as expected, such as when the sensor has drifted or is no longer correctly positioned.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Check-engine light or hybrid-system warning
- Reduced hybrid power or performance
- Hybrid-system temperature warning
How to diagnose it
- Capture freeze-frame data and compare sensor F live temperature with other converter readings and ambient conditions for an implausible value or response.
- With the hybrid system safely powered down per service information, inspect sensor F's position and mounting for displacement.
- Check the sensor F connector and harness for loose or corroded terminals, chafing, pinching, or other damage.
- Measure sensor F's resistance or signal response across temperature changes and compare it with the manufacturer's specification.
- If sensor F and its wiring check out, verify the ECM reference and ground circuits using the vehicle wiring information.
Common fixes
- Reposition and secure sensor F in its specified mounting location.
- Repair damaged wiring or poor contact at sensor F's connector.
- Replace sensor F if its response has drifted outside the manufacturer's specification.
- Repair a confirmed reference, ground, or ECM circuit fault.
Can I keep driving?
Keep driving limited and avoid high-load use because the ECM may reduce hybrid power or lack reliable converter temperature feedback. Stop if a hybrid-system temperature warning appears or reduced power becomes severe.
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.