I am on my third Camry, and I had this light come on with this current car. From the manual:
(e) Malfunction Indicator Lamp
This lamp comes on when the ignition
key is turned to the "ON" position and
goes off after the engine starts. This
means that the warning light system is
operating properly.
If the lamp remains on, or the lamp
comes on while driving, first check the
followings.
Empty fuel tank
If the fuel tank is empty, refuel immediately
Loose fuel tank cap
If the fuel tank cap is loose, securely
tighten it.
These cases are temporary malfunctions.
The malfunction indicator lamp will go off
after taking several driving trips.
If the lamp will not go off even after the
several trips, contact your Toyota dealer
as soon as possible.
If the fuel tank is not empty or the fuel
tank cap is not loose...
There is a problem somewhere in the
engine, emission control system, electronic
throttle control system, automatic
transmission electrical system or warning
light system itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.
If the engine speed does not increase with
the accelerator pedal depressed down,
there may be a problem somewhere in
your electronic throttle control system.
At this time, vibration may occur. However,
if you depress the accelerator pedal
more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle
checked by your Toyota dealer as soon as
possible.
Even if the abnormality of the electronic
throttle control system is corrected during
low speed driving, the system may not be
recovered until the engine is stopped and
the ignition key is turned to "ACC" or
"LOCK" position.
CAUTION
Be especially careful to prevent erroneous
pedal operation.
Emissions inspection and maintenance
(I/M) programs
Your vehicle may not pass a state
emission inspection if the malfunction
indicator lamp remains on. Contact your
Toyota dealer to check your vehicle's
emission control system and OBD
(On- Board Diagnostics) system before
taking your vehicle for the inspection.
For details, see "Emissions Inspection and
Maintenance (I/M) programs" on page 254
in Section 6.
My problem was loose gas cap. I didn't really feel confident in my own diagnosis, so I took my car in and they verified there were no other problems. Take it in. Though you should also read your owner's manual.
(e) Malfunction Indicator Lamp
This lamp comes on when the ignition
key is turned to the "ON" position and
goes off after the engine starts. This
means that the warning light system is
operating properly.
If the lamp remains on, or the lamp
comes on while driving, first check the
followings.
Empty fuel tank
If the fuel tank is empty, refuel immediately
Loose fuel tank cap
If the fuel tank cap is loose, securely
tighten it.
These cases are temporary malfunctions.
The malfunction indicator lamp will go off
after taking several driving trips.
If the lamp will not go off even after the
several trips, contact your Toyota dealer
as soon as possible.
If the fuel tank is not empty or the fuel
tank cap is not loose...
There is a problem somewhere in the
engine, emission control system, electronic
throttle control system, automatic
transmission electrical system or warning
light system itself.
Contact your Toyota dealer as soon as
possible to service the vehicle.
If the engine speed does not increase with
the accelerator pedal depressed down,
there may be a problem somewhere in
your electronic throttle control system.
At this time, vibration may occur. However,
if you depress the accelerator pedal
more firmly and slowly, you can drive your
vehicle at low speeds. Have your vehicle
checked by your Toyota dealer as soon as
possible.
Even if the abnormality of the electronic
throttle control system is corrected during
low speed driving, the system may not be
recovered until the engine is stopped and
the ignition key is turned to "ACC" or
"LOCK" position.
CAUTION
Be especially careful to prevent erroneous
pedal operation.
Emissions inspection and maintenance
(I/M) programs
Your vehicle may not pass a state
emission inspection if the malfunction
indicator lamp remains on. Contact your
Toyota dealer to check your vehicle's
emission control system and OBD
(On- Board Diagnostics) system before
taking your vehicle for the inspection.
For details, see "Emissions Inspection and
Maintenance (I/M) programs" on page 254
in Section 6.
My problem was loose gas cap. I didn't really feel confident in my own diagnosis, so I took my car in and they verified there were no other problems. Take it in. Though you should also read your owner's manual.