What it means
The ECM detects a range/performance fault on the dc/dc converter temperature sensor e 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 ECM uses temperature sensor E to track heat at its monitored point in the DC/DC converter, which converts high-voltage hybrid-system power to lower-voltage power. This range/performance code sets when the signal is electrically plausible but does not respond as expected for converter temperature, so the ECM cannot rely on it for control.
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
- Record freeze-frame data and compare sensor E live temperature with other converter temperature readings and ambient conditions to see whether it is implausible or slow to change.
- With the system safely powered down according to the vehicle service information, inspect sensor E's mounting and connector for displacement, damage, moisture, or corrosion.
- Check the sensor E harness for chafing, pinched sections, loose terminals, or poor contact that could distort the reading.
- Compare sensor E resistance or signal response at known temperatures with the manufacturer's specification to identify drift or an aged sensor element.
- If the sensor and wiring pass, verify the ECM's sensor E reference and ground circuits using the vehicle wiring information before suspecting the control module.
Common fixes
- Secure sensor E in its specified mounting position.
- Repair a loose, damaged, or corroded sensor E connector or harness.
- Replace temperature sensor E if its response is outside the manufacturer's specification.
- Repair a confirmed reference, ground, or ECM circuit fault.
Can I keep driving?
Limit driving and avoid high-load or long trips because unreliable converter temperature feedback can cause reduced hybrid power or inadequate thermal protection. Stop safely if a hybrid-system temperature warning appears or power drops sharply.
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.