P0E28: Drive Motor Inverter Temperature Sensor H Circuit

What it means

The drive motor inverter temperature sensor H circuit has an electrical fault, so its reading may be unavailable or unreliable.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Inverter temperature sensor H measures temperature at its own monitored point in the drive motor inverter. P0E28 indicates an electrical fault in the H sensor circuit, so the control module may not receive a usable temperature reading and may limit motor output to protect the inverter.

Common causes

Most likely first.

1. Sensor failed
2. Wiring or connector fault

Symptoms

• EV/hybrid system warning light on
• Reduced motor power or torque
• Possible limp mode or vehicle shutdown

How to diagnose it

1. Save freeze-frame data and check sensor H's live reading for a missing or implausible value, comparing it with other inverter temperature readings.
2. Power the vehicle down according to its service instructions and inspect sensor H's connector and harness for loose pins, corrosion, damage, or disconnection.
3. Use the manufacturer's wiring diagram to check continuity and for shorts in the sensor H signal, supply, and return circuits.
4. Test sensor H against the manufacturer's procedure to determine whether the sensor itself has failed.
5. If sensor H and its wiring pass, check the inverter control module input and related connections using the manufacturer's diagnostic steps.

Common fixes

• Reconnect or secure the sensor H connector.
• Clean or repair damaged or corroded sensor H terminals.
• Repair an open or short in the sensor H wiring.
• Replace sensor H if it fails the specified test.
• Repair the inverter control module input circuit if the sensor and harness test correctly.

Can I keep driving?

Avoid normal driving if the vehicle has reduced power or an EV/hybrid warning, because limp mode or shutdown is possible. Arrange prompt diagnosis and stop safely if power drops suddenly.