P0E5A DC/DC Converter Temperature Sensor C Circuit Low

P0E5A means the voltage from DC/DC converter temperature sensor C has fallen below its valid window. With the NTC thermistors common in power electronics, a low voltage translates into an implausibly hot reading, so a grounded signal wire or a failed sensor is far more likely than genuine overheating. No manufacturer documents P0E5A publicly. Ford gives an idea of the window for its sensor C, the inductor sensor of the boost converter: anything under 0.067 V counts as a fault, but Ford stores it as P0E59, not as P0E5A. CARB requires out-of-range monitoring of hybrid input components. Because the controller must assume overtemperature, it usually derates the converter at once, which can reduce electric power. The high-signal counterpart is P0E5B.

Likely causes

Symptoms

• Hybrid system warning
• Converter derated, reduced electric power

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, fordservicecontent.com.