Lexus warning lights: what each light means
In Lexus models, the documented faults light up 6 warning lights on the dashboard. The most frequent: hybrid system warning (3 faults), overheating (2 faults) and engine warning light (2 faults). Overheating calls for stopping as soon as possible.
Which warning lights the faults of Lexus trigger
Red ones first, and those that call for stopping. Below each warning light, the documented faults that trigger it, with their pages.
Overheating or temperature warning light
Urgency: As soon as possibleRedSymbol: thermometer over wavy lines (coolant)
The temperature needle climbs towards the red zone or the coolant warning light comes on. It usually points to a lack of coolant, a leak, or a failing thermostat or water pump. Driving on can warp the cylinder head or damage the gasket.
What to do: Stop as soon as you can and switch the engine off. Do not open the coolant reservoir cap while it is hot. If coolant is missing, do not set off again until you have found the leak.
2 documented faults that trigger it in the Lexus
- Critical severity: Warped cylinder head gasket and oil consumption on the 2.2 D-4D · 2.0/2.2 D-4D engine · IS II
- High severity: Inverter (IPM module) overheating and loss of drive · 1.8 Hybrid engine · CT
Airbag warning light on
Urgency: Garage soonRedSymbol: a seated person wearing a seat belt with a circle (the inflated airbag) in front; in some cars, the letters SRS or AIRBAG
The airbag warning light means the system has detected a fault and an airbag or seatbelt pretensioner may not deploy in a crash. Causes range from a connector under the seat to the control unit or the airbag itself.
What to do: Have it diagnosed as soon as possible and check with the VIN whether the car has any outstanding airbag recall.
1 documented fault that triggers it in the Lexus
- High severity: Airbag inflator for the curtain airbags with a possible micro-crack in the weld · outside the engine · CT
Engine fault warning light (check engine)
Urgency: Garage soonYellow or amberSymbol: outline of an engine seen from the side, in yellow or orange
The orange engine-shaped warning light comes on when the ECU detects a fault affecting combustion or emissions. If it flashes, it usually points to misfires that can damage the catalytic converter.
What to do: If it stays on steadily, you can drive gently to a garage and ask for a fault code read-out. If it flashes or you notice a loss of power, slow down and get to a garage as soon as possible.
2 documented faults that trigger it in the Lexus
- Medium severity: EGR valve clogged with soot · 2.0/2.2 D-4D engine · IS II
- Medium severity: Injector wear and failure · 2.0/2.2 D-4D engine · IS II
ABS or ESP warning light on
Urgency: Garage soonYellow or amberSymbol: the letters ABS, usually inside a circle, in amber or orange
It indicates a fault in the anti-lock braking or stability control system: often a dirty or damaged wheel speed sensor, its wiring or the hydraulic unit. The brakes still work, but without those aids.
What to do: Drive carefully, especially in the rain, and ask for a fault code read-out. It is often fixed with a wheel sensor.
1 documented fault that triggers it in the Lexus
- Critical severity: Brake actuator failure (hard pedal, loss of assistance) · 1.8 Hybrid engine · CT
Particulate filter warning light (DPF)
Urgency: Garage soonYellow or amberSymbol: particulate filter symbol on the dashboard, normally amber; its design varies by manufacturer
On modern diesels it means the particulate filter is clogged with soot and has not been able to regenerate. It is common in cars used mostly for short town journeys, although it can also be caused by a sensor or by an injection or EGR fault.
What to do: If the handbook allows it, a 20-minute drive on a motorway at a steady speed can complete the regeneration. If the light stays on or you lose power, go to a garage.
1 documented fault that triggers it in the Lexus
- Medium severity: D-CAT particulate filter clogging · 2.0/2.2 D-4D engine · IS II
Hybrid system fault warning light or message
Urgency: Garage soon
Hybrid Toyotas and Lexuses show their own warning (a triangle or a message on the dashboard) when the hybrid system management electronics, such as the inverter, the battery or the electric motors, detect a fault, separate from the generic engine fault warning light. In some cases the car goes into a limited driving mode or loses electric drive.
What to do: If you also notice a loss of power or the car stalls, stop as soon as it is safe. Ask a garage with the right equipment to read the codes of the hybrid control unit, not just the petrol engine one.
3 documented faults that trigger it in the Lexus
- Critical severity: The car loses drive or stalls because of a hybrid system fail-safe mode fault · 1.8 Hybrid engine · CT
- High severity: Inverter (IPM module) overheating and loss of drive · 1.8 Hybrid engine · CT
- High severity: Degradation or premature failure of the hybrid battery · 1.8 Hybrid engine · CT
Frequently asked questions
Which warning lights come on most in the Lexus?
Hybrid system warning: 3 documented faults, such as the car loses drive or stalls because of a hybrid system fail-safe mode fault. Overheating: 2 documented faults, such as warped cylinder head gasket and oil consumption on the 2.2 D-4D. Engine warning light: 2 documented faults, such as EGR valve clogged with soot.
Which warning light of Lexus is the most serious?
Overheating: its urgency is “as soon as possible”. Stop as soon as you can and switch the engine off. Do not open the coolant reservoir cap while it is hot. If coolant is missing, do not set off again until you have found the leak.
Which Lexus models have the most faults that trigger warning lights?
Lexus CT (6 faults) and Lexus IS II (4 faults).
A warning light has come on in the Lexus: what should I do?
Find which warning light it is on this page and check its urgency. With overheating, stop as soon as possible somewhere safe. For the others, book an appointment at a garage and have them read the fault code with an OBD reader: it shows which system has failed.