P0E2A

Code

Generic P — Powertrain

Drive Motor Inverter Temperature Sensor H Circuit Low

Brand: Generic

Type: P — Powertrain

Views: UK: 21 EN: 28 RU: 25

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Page language: EN

Causes

Short to ground in the sensor signal wire
Open, damaged, or corroded connector or wiring
Failed temperature sensor (thermistor) in inverter
Missing or defective pull-up/reference circuit in inverter control electronics
Intermittent connection from vibration or water intrusion
Related fault in inverter control module or internal harness

Symptoms

Malfunction Indicator Lamp (MIL) / warning lamp illuminated
Drive or inverter derate, reduced power or limited performance
Reduced or disabled regenerative braking
Inverter temperature reading abnormally low or 'unknown' on live data
Possible stored related hybrid/EV system faults or limp mode

What to check

Retrieve freeze frame and live data with a scan tool; note inverter temperature values and whether the reading is abnormally low or stuck
Check for any other stored DTCs that could point to wiring, communication, or inverter issues
Visual inspection of harness and connectors for damage, corrosion, or water ingress at the inverter and junction points
Backprobe connector and measure sensor signal voltage with ignition/vehicle in the required state (follow service procedure)
Check for reference voltage/pull-up presence at the sensor connector
Perform continuity and short-to-ground checks on the signal wire with the low-voltage system isolated from high-voltage components

Signal parameters

Sensor type: typically a thermistor (resistive temperature sensor) providing a voltage signal to inverter/ECU
Expected signal voltage range (typical): 0.5 V to 4.5 V across operating temperature range; exact values vehicle-specific
'Low' fault threshold: signal near 0 V to < ~0.5 V (indicates short to ground or very low resistance)
Open-circuit/output-fault may show voltage near reference rail or diagnostic-specific value (may register as 'high' or 'open')
Sensor output is steady DC (no waveform) and varies slowly with temperature change

Diagnostic algorithm

Safety first: follow vehicle manufacturer high-voltage procedures. Remove service disconnect, wear PPE, and verify HV is de-energized before any work on inverter or HV harness.
Connect a capable scan tool. Record freeze-frame data and monitor live inverter temperature H sensor value while key/ignition is in the required state.
Inspect visible wiring and connectors for damage, chafing, corrosion, or water entry between the inverter and any junction points. Repair any obvious faults.
With ignition on (and HV safe according to procedure), backprobe the sensor connector: verify presence of reference/pull-up voltage and measure signal voltage. Compare to expected ranges.
If signal is low, isolate the low-voltage circuit from the inverter end (disconnect connector) and measure continuity and short-to-ground of the signal conductor to chassis ground using a digital multimeter. A short (< a few ohms) indicates wiring short to ground.
Measure sensor resistance at the sensor (with connector disconnected) across the sensor terminals at ambient temperature. Compare to specification or to the same type sensor chart. If resistance is near zero or out of range for expected temperature, replace the sensor.
If wiring checks OK and sensor resistance is correct, inspect inverter-side connector and measure for correct pull-up/reference resistor presence. Check for continuity from the sensor signal pin to the inverter input pin.
Wiggle tests while monitoring live data: move harness and connectors to try to reproduce intermittent behavior.
If wiring and sensor are good but fault persists, suspect internal inverter control board input or failed pull-up. Replacement or repair of the inverter assembly may be required.
After repairs, clear DTCs, recheck live data, and perform an operational drive cycle or inverter activation sequence to verify the fault does not return.

Likely causes

Signal wire shorted to chassis ground at a harness chafe point
Connector pin pushed out, corroded, or poorly seated at inverter or junction
Temperature sensor element shorted internally to ground
Faulty inverter control board input or failed pull-up resistor
Aftermarket repair or previous servicing disturbed HV/low-voltage harness

Fault status

⚠️ Status

Drive Motor Inverter Temperature Sensor H Circuit Low — Sensor signal voltage below expected threshold. Possible short to ground, wiring/connector fault, sensor failure, or inverter input fault. May cause inverter derate or limited drive functionality.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1.5-3.5 hours