P0E5C: DC/DC Converter Temperature Sensor C Circuit Intermittent/Erratic

P0E5C flags a sensor C signal that changes faster than the part it watches could heat or cool. A converter inductor or heat sink has thermal mass, so a jump of many degrees within a few milliseconds points to a contact problem in the circuit, not to the converter itself. No manufacturer documents P0E5C publicly. The sensor is known from Ford, where sensor C watches the boost converter inductor and is checked only through P0E59 with fixed voltage and temperature limits; an erratic check is not described there. CARB requires hybrid input components to be monitored for circuit faults. Typical causes are a loose terminal, vibration damage or moisture at the converter connector. The fault may come and go between drives, so a wiggle test with live data helps more than a static measurement.

High severity. Can I keep driving?If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

Symptoms

Hybrid warning that comes and goes
Short episodes of reduced electric power

Most likely causes

Loose or widened terminal at the sensor or converter connector
Moisture or corrosion in the connector
Chafed wire with intermittent contact

What to check, in order

Start with the simplest. You can tick off each step.

Read the codes with a hybrid-compatible scanner and write down the freeze frame data
Gently move the wiring with the engine running and watch whether the reading changes.
Make sure the battery cooling air intake is clean
Check the 12 V auxiliary battery, which can also trigger warnings
Leave any high-voltage measurements to a specialized repair shop

Good to know

Repair difficulty: hard
It can trigger limp mode.
It affects emissions.

What each character of P0E5C means

P: Powertrain: engine and transmission
0: Generic code: same on every make
E: Subsystem depends on the code range
5C: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0E5C?

If the car still runs, drive as little as possible and go to a specialized repair shop. Do not touch the orange cables: they carry high voltage.

What causes code P0E5C?

The most common causes are: loose or widened terminal at the sensor or converter connector; moisture or corrosion in the connector; chafed wire with intermittent contact.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.