P0E43: Hybrid/EV Powertrain Control Module B

What it means

The hybrid powertrain control module B reports a generic fault. Internal self-tests fail or response time outside calibration.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Hybrid/EV powertrain control module B manages or coordinates part of the vehicle’s hybrid or electric powertrain. The system detects a generic fault when module B fails an internal self-check or does not respond within its expected time, so the code does not by itself identify a failed component.

Common causes

Most likely first.

1. Internal module fault
2. Communication lost

Symptoms

• Hybrid/EV system warning light may turn on
• Reduced power or limp mode
• Charging or electric drive may be limited

How to diagnose it

1. Record freeze-frame data and scan all modules for related codes that may identify the cause of module B’s fault or lost response.
2. Check whether module B communicates with the scan tool and note any communication or response-time faults.
3. Inspect the module B connectors and accessible harness for loose connections, corrosion, moisture, or damage.
4. Check module B’s power and ground circuits under load and compare results with the manufacturer’s specification.
5. If supply, ground, and communication wiring are sound, use the manufacturer’s procedure to assess module B’s internal fault.

Common fixes

• Repair loose, corroded, or damaged module B connector terminals.
• Repair a confirmed power, ground, or communication wiring fault to module B.
• Restore module communication after correcting any identified network fault.
• Repair or replace module B only if the manufacturer’s diagnostic checks confirm an internal failure.

Can I keep driving?

Reduced power, limited electric drive, or restricted charging may occur, so avoid demanding driving if the vehicle is in limp mode. Stop if power becomes unpredictable or a high-voltage warning appears, and arrange prompt diagnosis.