Check Engine light on

I see you're in CA. Are you able to get your car smogged with this problem? The check engine light is primarily for emissions control faults, so I'd be surprised if you can get a clean check. As far as solving, you need to get a solid fault code to chase it down. Try taking to an auto parts store (or dealer) while the light is still on to get a fault code.

 

Or pry a few dollars out of your wallet to get your own code reader. Then read it when it happens. You can get something for your phone for like $30. Countless threads here about it.

Five basic things every car owner should have:
1. Tire pressure gauge.
2. Air pump or compressor.
3. Code reader.
4. Multimeter.
5. Spare tire & jack.

 

If a malfunction isn’t detected consistently, the check engine (malfunction indicator) lamp will turn off on its own, but in general, the diagnostic trouble code (DTC) should still be stored in the car’s computers.

There are four different “crankshaft position sensor” DTCs—P001600, P03352A, P033531, and P033562—but according to the troubleshooting procedures in the Repair Manual (more info), any of them can caused by trouble in other areas, not just by a failed sensor. Do you know which code or codes the car is reporting?

That’s disappointing to hear. Unless the car has more than 150,000 miles on the odometer, problems such as you describe should be covered under the California Emission Control Warranty, described in the Warranty and Maintenance Guide (PDF), pages 24–29.

Besides @jerrymildred's kind suggestion to get your own OBD II scan tool—even inexpensive ones can read engine and emissions DTCs—you could also force the issue, assuming the car still has emissions warranty coverage, by having it tested at a Smog Check station, as @FuelMiser kindly suggested, while the check engine light is on, just to get an official report showing that it failed. You’d have to pay for the test, but the report would prove that there is a problem that Toyota is obligated to fix under warranty.

If the dealer can’t solve the problem, ask them to open a case with Toyota’s Technical Assistance System (TAS), the dealer-only support line, as required by Toyota’s “Fix It Right The First Time” repair protocol. Also, don’t hesitate to contact Toyota, since it’s Toyota, not the dealer, that has the warranty obligation to you.