P0E5B: DC/DC Converter Temperature Sensor C Circuit High

P0E5B is stored when the signal of DC/DC converter temperature sensor C rises above its valid window. On an NTC circuit with pull-up resistor, that is the typical picture of an unplugged connector, a broken wire or a short to a supply voltage, and it reads as a converter far colder than possible. No manufacturer documents P0E5B publicly. Ford's limit for its sensor C, the boost converter inductor sensor, lies at 4.86 V; above that a fault is logged, yet Ford reports it as P0E59. Range checks of this kind are mandatory under CARB for hybrid inputs. Since a cold reading would hide real overheating, the controller treats the converter temperature as unknown and usually limits power. A connector check is the obvious first step. P0E5A is the low-signal counterpart.

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 system warning
Power limited as a precaution

Most likely causes

Connector unplugged or sensor wire broken
Signal shorted to a supply voltage
Thermistor open internally

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
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
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

It can trigger limp mode.
It affects emissions.

What each character of P0E5B means

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

Frequently asked questions

Can I keep driving with code P0E5B?

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 P0E5B?

The most common causes are: connector unplugged or sensor wire broken; signal shorted to a supply voltage; thermistor open internally.

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.