Toyota Electrical Diagnostics
Toyota uses a Main Body ECU and sub-ECUs, a gateway, and Techstream diagnostics. Common faults include body-ECU locking and lighting issues, smart-key and immobiliser faults, and charging warnings. Hybrid models add high-voltage system diagnostics.
Toyota Control Modules & Electronics
Key modules and electronic systems used across Toyota vehicles. Correct identification of the module is the first step in proper diagnosis.
Main Body ECU
Central body electronics.
Gateway ECU
Network communication.
Engine / Hybrid ECU
Powertrain and hybrid management.
Smart Key / Immobiliser
Keyless and security.
HV Battery / Inverter
High-voltage hybrid/EV systems.
Common Toyota Electrical Faults
Faults we frequently see on Toyota vehicles. Each links to a detailed, all-makes guide covering symptoms, causes and our diagnostic approach.
Body Control Module (BCM) Faults
Central body electronics controlling locking, lighting, wipers and comfort.
READ GUIDEKey Not Detected
Vehicle doesn't recognise the key — won't start or unlock.
READ GUIDEABS Warning Light
ABS warning on — stability and braking-system fault.
READ GUIDEBattery Warning Light & Vehicle Not Charging
Charging-system fault — battery warning or vehicle not charging.
READ GUIDEParking Assist Unavailable
Parking sensors or park assist not working.
READ GUIDEAirbag / SRS Warning Light
Airbag or SRS warning light on — restraint-system fault.
READ GUIDEElectric Power Steering Fault
EPS warning — steering assistance reduced or unavailable.
READ GUIDEAir Suspension Faults
Air-suspension warning — ride-height or compressor fault.
READ GUIDECAN Bus / Network Communication Faults
Network communication fault affecting multiple modules.
READ GUIDEToyota Models We Cover
Toyota Electrical Fault?.
Tell us about your Toyota, the symptoms and any warning messages. OBD_PAL diagnoses the complete system before recommending any repair — don't guess, diagnose it properly.