MG HS Hybrid Not Charging Repair

HV System Fault & On-Board Charger Fault Diagnosis

At KMC Electric, we specialise in diagnosing and repairing electric and hybrid vehicle charging faults, including issues affecting the MG HS Plug-in Hybrid.

A recent vehicle came to us with a complaint of:

• Vehicle not charging
• High voltage fault warning displayed on the dashboard
• Vehicle still able to drive normally despite the warning

This is a fault that can be confusing for owners, as the vehicle may appear to drive normally while refusing to charge.

Our specialist diagnostic process allowed us to quickly identify and repair the underlying issue.

Common MG HS Hybrid Fault Codes

During diagnosis, this vehicle was showing the following fault codes:

• P1E5C – On-board charger relay failed open circuit
• P1EAF – On-board charger voltage mismatch

These fault codes often indicate an issue with the charging system, battery management system, or internal high-voltage switching components.

What Caused the Fault?

In this case, the root cause was found to be a stuck 12V contactor / relay within the Battery Management System (BMS).

This caused the onboard charger to see incorrect system voltage, creating a mismatch between expected and actual voltage readings.

As a result:

• The vehicle would not accept charge
• A high-voltage warning was displayed
• Fault codes were stored in the system

Because the contactor had failed internally, the issue could not be resolved without removing and repairing the affected unit.

Our Repair Process

At KMC Electric, we carried out a full professional repair process:

Initial Diagnostic Checks

We confirmed the fault codes and verified charging system operation.

High Voltage Battery Removal

The high-voltage battery pack was safely removed from the vehicle.

Battery Management System Removal

The Battery Management System (BMS) and integrated contactor assembly were removed for further inspection.

Specialist Repair

The BMS / contactor assembly was sent away for professional repair.

Reassembly & Testing

Once repaired, the unit was reinstalled and the battery reassembled.

We then completed:

• Final system checks
• Charging system verification
• Fault code clearing
• Road testing and confirmation of successful repair

The vehicle was then fully operational and charging correctly.

MG HS Hybrid Charging Fault Specialist

At KMC Electric, we have the qualifications and experience to safely diagnose and repair high-voltage systems.

We offer:

• Level 4 EV Diagnostic & Repair Technician
• EV qualified since 2016
• Over 25 years of automotive experience
• Independent EV & hybrid specialist

We focus on repairing components where possible, helping customers avoid unnecessary replacement costs.

Common Symptoms of This Fault

If your MG HS Hybrid is experiencing similar issues, symptoms may include:

• Vehicle not charging
• HV system warning on the dashboard
• Charging interrupted or not starting
• Fault codes relating to onboard charger or voltage mismatch
• Vehicle still drives despite the warning

Early diagnosis can help prevent further issues.

Book MG HS Hybrid Charging Fault Diagnosis

If your MG HS Hybrid is not charging, or you have seen fault codes such as P1E5C or P1EAF, we can help.

📍 KMC Electric – Kettering
📧 [email protected]

Independent EV, Hybrid & Tesla Specialist