EV Diagnostic Guide

Battery State of Health (SoH) is one of the most critical metrics for any electric vehicle owner. It represents the current capacity of your battery pack as a percentage of its original design capacity. A new EV battery typically starts at 100% SoH and gradually degrades over time due to charge cycles, temperature exposure, and calendar ageing. Most modern EVs experience roughly 2–4% degradation per year under normal conditions. Signs of accelerated battery degradation include reduced maximum range, longer charging times, sudden drops in displayed range, and increased sensitivity to cold weather. ElectraMedic can identify battery degradation patterns and classify them with a diagnostic identity, helping you understand whether degradation is within normal parameters or indicative of a deeper cell-level fault.

Charging faults are among the most common issues reported by EV owners. They can manifest as a charge session that stops prematurely, a vehicle that refuses to accept DC fast charging above a certain state of charge, or unusually slow charging speeds. Root causes vary widely: a faulty onboard charger (OBC), a degraded charge port, a communication error between the vehicle and the EVSE (charging station), thermal limits imposed by the battery management system (BMS), or a software bug. OBD-II fault codes related to charging (such as P0D00-series codes) can help pinpoint the subsystem at fault. ElectraMedic analyses your symptoms and fault codes to assign a named charging fault identity and probability-ranked causes.

Electric vehicle thermal management systems control the temperature of battery cells, the motor, the inverter, and the power electronics. When thermal management fails or becomes inefficient, it can cause reduced charging speed (thermal throttling), reduced range in cold weather, overheating warnings during fast charging or spirited driving, and in severe cases, battery degradation acceleration. Thermal faults often present alongside other symptoms and can be tricky to isolate. Common causes include coolant pump failure, coolant leaks, blocked heat exchangers, failed temperature sensors, or BMS calibration errors. Our diagnostic engine classifies thermal anomalies into patterns such as "Thermal Drift Syndrome" or "Cell Temperature Imbalance Identity" to give you a clear starting point for investigation.

Regenerative braking is a core feature of electric vehicles that recovers kinetic energy during deceleration, converting it back into electricity and extending range. When regen braking weakens or disappears, it is usually a symptom of an underlying issue rather than a fault in the regen system itself. Common causes include a nearly full battery (BMS reduces regen to protect cells), cold battery conditions, a fault in the motor inverter, or a software glitch. Persistent or sudden regen loss should be investigated, as it can indicate inverter degradation or BMS faults. ElectraMedic identifies the "Regen Loss Pattern" and helps distinguish between expected system behaviour and genuine faults.

High-voltage (HV) system warnings are among the most serious alerts an EV can produce. They can indicate insulation faults, contactor failures, HV interlock loop breaks, or communication failures within the HV network. These warnings often trigger a "limp mode" or complete shutdown to protect occupants. Never attempt to open or inspect HV components yourself — always treat HV warnings as serious safety events requiring qualified technician attention. ElectraMedic will classify the warning, explain what it likely means in plain language, flag the urgency level as Immediate, and guide you on safe next steps — including whether to stop driving immediately or whether the vehicle is safe to drive to a service centre.

OBD-II fault codes provide a standardised window into your vehicle's electronic systems. For EVs and PHEVs, codes in the P0D00–P0DFF range cover hybrid and electric powertrain faults, while manufacturer-specific codes (P1xxx, B-codes, C-codes, U-codes) cover proprietary systems unique to each brand. Reading these codes with a compatible scan tool and interpreting them correctly requires understanding the specific vehicle architecture. A code like P0D13 (High-Voltage Battery Pack Voltage Sense Circuit) means something very different on a 2018 Nissan Leaf than on a 2023 Tesla Model 3. ElectraMedic accepts raw OBD-II code dumps and interprets each code in the context of your specific make, model, and year — providing a complete diagnostic identity for the full set of active faults.