Fault Code Database
EV DTC Code Library
Browse diagnostic trouble codes for every major EV platform. Click any code to start the step-by-step repair wizard.
B1234LowBody Controller Unexpected Wake State
The vehicle's primary body control network is failing to sleep when parked, staying stuck in an active state that draws continuous current. This internal logic bug prevents the vehicle from entering deep sleep mode, rapidly draining the low-voltage 12V auxiliary battery overnight.
Tesla, Rivian, Ford
BMS_a035CriticalBMS Critical Structural Fault Detected
The high-voltage Battery Management System has identified a structural hardware fault or internal component fracture inside the under-car battery containment envelope. This is a severe safety code indicating internal physical damage, structural degradation, or a catastrophic failure within the structural pack assembly.
Shop RequiredFord, Chevrolet
CHG_w012LowCharge Port Latch Engagement Warning
The charge port controller is warning that the internal locking latch failed to clamp securely around the charging handle pin. Because high-voltage charging cannot safely begin without a locked handle, the vehicle will block power flow until a lock is achieved.
Tesla, Ford, Hyundai
DI_a040HighDrive Unit Phase Current Fault
The motor control module has detected an irregular electrical wave mismatch across the three individual power phase cables running into the drive motor. This severe electrical deviation causes immediate limp-home modes or shuts down the drive unit to protect circuits from high-amp shorting.
Shop RequiredTesla, Ford
DI_w014WarningDrive Unit Mechanical Bearing Warning
The drive unit housing sensors have logged an anomalous structural signature or high thermal spike coming from the main internal rotor shaft bearing. This indicates internal mechanical wear that, if ignored, can damage the motor's core gear teeth.
Shop RequiredTesla, Ford
MCU_w023LowMedia Control Unit Warning Active
The car's primary infotainment and Media Control Unit has logged a non-fatal internal logic glitch or high processor temperature loop. While the vehicle remains fully safe to drive, secondary convenience features like GPS tracking, sound systems, and camera feeds may lag or freeze.
Tesla, Ford
P0AA1CriticalHigh Voltage Battery Welded Positive Contactor
The Battery Management System has identified a dangerous hardware fault where the primary positive high-voltage contactor relay switch has physically welded itself shut due to an electrical arc. This means the lethal high-voltage energy grid stays live outside the battery case even when the vehicle is completely shut off.
Shop RequiredFord, Hyundai, Chevrolet
P0AA4CriticalHigh Voltage Contactor Switch Logic Error
The vehicle's main powertrain monitor has logged an incorrect operation sequence across the primary high-voltage battery contactor switches. The vehicle cannot confirm if the internal high-current relays are correctly open or closed, triggering an immediate non-start condition to protect modules.
Shop RequiredFord, Hyundai, Chevrolet
P0ADACriticalHigh Voltage Junction Box Structural Failure
The internal power distribution junction hardware located inside the main battery container has suffered an electrical component failure or insulation breakdown. This prevents safe high-voltage routing between the core battery modules, the drive motors, and the onboard charger.
Shop RequiredHyundai, Ford
P0C11HighDrive Motor Inverter Phase Circuit Short
The main powertrain computer has detected a serious short circuit or abnormal high-current drop inside the internal phase drive circuits of the electric motor inverter module. This stops the car from safely spinning the drive motor, causing an immediate halt in power delivery.
Shop RequiredFord, Jaguar
P0C2FWarningEV Thermal Management System Control Error
The primary vehicle control computer has lost operation over the intricate network of electronic multi-way directional valves that route cooling fluid through the battery pack and powertrain. This leaves the car unable to cool its battery cells or warm its cabin, throwing the car into limp mode.
Shop RequiredTesla, Ford
P1A10HighFord High Voltage System Emergency Shutdown
The primary control module triggered an emergency isolation of the high-voltage electrical network to minimize arc risks. This hard fault typically stems from a breakdown or bad safety contactors inside the main battery distribution hardware.
Ford
P1A9096CriticalICCU DC/DC Converter Hardware Fault
The vehicle's Integrated Charging Control Unit (ICCU) has suffered an internal hardware sensor failure within its built-in DC-to-DC converter matrix. This critical failure blocks the car's ability to pull high-voltage battery power down to maintain the auxiliary 12V loop, causing the car to quickly lose electronic systems.
Shop RequiredHyundai, Ford
THC_a102CriticalBattery Thermal Excursion Safety Limit Reached
The thermal control framework has tracked extreme, dangerous peak temperature numbers within the main high-voltage battery array blocks. The car will lock open safety contactor blocks and stop all driving or high-power fast charging loops to eliminate battery fires.
Shop RequiredNissan, Tesla, Ford
U0140HighLost Communication With Body Control Module
The vehicle's high-speed central data network has lost all real-time data connection contact with the primary Body Control Module (BCM). Because this computer module controls basic infrastructure like exterior lighting, door electronic latches, and window systems, a communication drop bricks peripheral operations.
Ford, Polestar
U1000LowOver-The-Air Update System Internal Fault
The vehicle's main network gateway has logged a deep internal processing error or firmware file corruption during an attempted Over-The-Air (OTA) software update. This system hang-up can lock or disable specific vehicle modules, preventing the car from clearing old fault memories until the software is restored.
Tesla, Ford, Rivian