What it means
The ECM detects a circuit low fault on the dc/dc converter temperature sensor d 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
DC/DC converter temperature sensor D sends a temperature signal to the control module from its designated converter location. This circuit-low code sets when the signal voltage is lower than the module expects, which can happen if the signal is shorted to ground, the sensor is internally shorted, or a corroded connection disrupts the circuit.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light or hybrid-system warning
- Reduced hybrid power or performance
- Hybrid-system temperature warning
How to diagnose it
- Save freeze-frame data and check for related converter temperature codes, since multiple low readings can suggest a shared circuit or supply problem.
- Read sensor D’s live temperature with a compatible scan tool and compare it with other converter temperatures for an implausibly extreme or fixed reading.
- With the vehicle safely powered down under its service procedure, inspect sensor D’s connector and harness for corrosion, pin damage, and wiring chafed against ground.
- Test the sensor D signal circuit for a short to ground and check connector continuity and terminals against the wiring diagram and manufacturer’s specification.
- If the circuit is sound, test sensor D itself by the manufacturer’s procedure to identify an internal short.
Common fixes
- Clean and secure corroded sensor D connector terminals if they can be properly restored.
- Repair a signal wire shorted to ground or other damaged wiring in the sensor D circuit.
- Replace sensor D if it is internally shorted or fails its specified test.
- Clear the code and verify that sensor D’s signal and temperature reading respond normally.
Can I keep driving?
The control module may limit hybrid output because it cannot rely on sensor D’s temperature signal. Avoid heavy loads and stop safely if a hybrid temperature warning or power restriction appears, since an inaccurate reading can impair converter protection.
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.