P0E1B: Hybrid/EV Battery Pack Coolant Pump B Control Circuit Low

P0E1B narrows a pump B command fault down to a level below the expected window, normally because the control or PWM wire has a ground fault, or because a driver that cannot raise it. No manufacturer documents P0E1B publicly. The nearest documented relative is P0C48 for pump A, which Ford listed for the 2020 Explorer, Police Interceptor Utility and Lincoln Aviator hybrids and traced to battery energy control module software that is reprogrammed. A software cause of that kind is worth ruling out first before cutting into the harness. Physically, a low reading often comes from insulation rubbed through on a bracket or from coolant wicking into the connector. CARB wants each thermal management output checked for such faults. If pump B stops as a result, the loop it serves loses flow. Open circuit is P0E1A, short to voltage P0E1C.

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

Check engine light on
Pump B does not run
Power limited when the components it cools get hot

Most likely causes

Pump B control or PWM wire shorted to ground
Coolant or water in the pump connector
Control module software fault, as seen by Ford on the pump A sibling
Internal short at the pump B control input

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
With the connector unplugged, check whether the signal wire is making contact with ground.
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: medium
It can trigger limp mode.
It affects emissions.

What each character of P0E1B means

P: Powertrain: engine and transmission
0: Generic code: same on every make
E: Subsystem depends on the code range
1B: Specific fault in that system

Frequently asked questions

Can I keep driving with code P0E1B?

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 P0E1B?

The most common causes are: pump B control or PWM wire shorted to ground; coolant or water in the pump connector; control module software fault, as seen by Ford on the pump A sibling.

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.