Page 469 of 628
4677-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
7
When trouble arises
Indicates that the engine coolant temperature is too high A buzzer also sounds.
→ P. 5 2 8
(GS350/GS200t only)
Indicates a malfunction in the vehicle’s charging system.
→Immediately stop the vehicle in a safe place and
contact your Lexus dealer. Continuing to drive the
vehicle may be dangerous.
(If equipped)
Indicates that the radar sensor is dirty or covered with
ice
A buzzer also sounds.
→ Clean the sensor.
Warning messageDetails/Actions
Page 530 of 628
528
GS350_200t_GS F_OM_OM30E86U_(U)7-2. Steps to take in an emergency
If your vehicle overheats
●The needle of the engine coolant temperature gauge (
→P. 86, 92) enters the
red zone or a loss of engine power is experienced. (For example, the vehicle
speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s Manual” is
shown on the multi-information display.
●Steam is coming from under the hood.
Stop the vehicle in a safe place and turn off the air conditioning system, and
then stop the engine.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the engine has cooled down sufficiently, inspect the hoses and cooling
core (radiator) for any leaks.
Radiator
Cooling fans
If a large amount of coolant leaks,
immediately contact your Lexus
dealer.
The following may indicate that your vehicle is overheating.
Correction procedures
1
2
3
1
2
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5297-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
7
When trouble arises
The coolant level is satisfactory if it is between the “FULL”/“F” and “LOW”/“L”
lines on the reservoir. Engine coolant reservoir
“FULL”/“F”
“LOW”/“L”
Coolant inlet cap
Intercooler coolant reservoir4
1
2
3
4
5
XGS350 XGS F
XGS200t
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5307-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
Add coolant if necessary.
Water can be used in an emergency if coolant is unavailable.
Start the engine and turn the air conditioning system on to check that the radi-
ator cooling fans operate and to check for coolant leaks from the radiator or
hoses.
The fans operate when the air conditioning system is turned on immediately after a
cold start. Confirm that the fans are operating by checking the fan sound and air flow.
If it is difficult to check these, turn the air conditioning system on and off repeatedly.
(The fans may not operate in freezing temperatures.)
If the fans are not operating:
Stop the engine immediately and contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the nearest Lexus dealer.
5
XGS350 XGS F
XGS200t
6
7
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5317-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
7
When trouble arises
■When adding engine coolant (GS350/GS200t)
Add coolant in accordance with the following procedure. Remove caps A and B.
Add engine coolant through the inlet of cap A up to the “[AR/GR] B” line, and then
install cap A.
Add engine coolant through the inlet of cap B until it is full, and then install cap B.
GS200t only: When installing cap B, apply coolant to the O-ring on the end of cap B.
Cap A
Cap B
“[AR/GR] B” line (Target fill line)
1
2
3
GS350 GS200t
1
2
3
Page 534 of 628

5327-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
WA R N I N G
■When inspecting under the hood of your vehicle
Observe the following precautions.
Failure to do so may result in serious injury such as burns.
●If steam is seen coming from under the hood, do not open the hood until the steam
has subsided. The engine compartment may be very hot.
●Keep hands and clothing (especially a tie, a scarf or a muffler) away from the fans and
belts. Failure to do so may cause the hands or clothing to be caught, resulting in seri-
ous injury.
●GS350: Do not loosen the coolant inlet cap
or the engine coolant reservoir cap while the
engine and radiator are hot.
High temperature steam or coolant could
spray out.
●GS F: Do not loosen the engine coolant res-
ervoir cap while the engine and radiator are
hot.
High temperature steam or coolant could
spray out.
●GS200t: Do not loosen the coolant inlet cap,
the engine coolant reservoir cap or the inter-
cooler coolant reservoir cap while the engine
and radiator are hot.
High temperature steam or coolant could
spray out.
Page 535 of 628
5337-2. Steps to take in an emergency
GS350_200t_GS F_OM_OM30E86U_(U)
7
When trouble arises
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has cool ed down sufficiently. Adding cool coolant
to a hot engine too quickly can cause damage to the engine.
■To prevent damage to the cooling system
Observe the following precautions:
●Avoid contaminating the coolant with foreign matter (such as sand or dust etc.).
●Do not use any coolant additive.
Page 549 of 628