2001 lexus check engine is flashin and trac light is ON after I helped jumping another car

SOURCE: my check engine trac off light came on

This happened to me as well, just a few weeks after buying our 1999 ES300. Took it into Lexus for regular maintenance and to check this out. Apparently, if you don't replace the gas cap correctly and tight enough this can cause the 'trac off' light to come one. It will go off a little while after the cap has been replaced correctly. This also happened with my 2006 Murano, 'check engine soon' message.

SOURCE: trac off and check engine light for lexus es 300

A week ago, on my Lexus ES 300 (2001), "Check Engine" and "Trac Off" lights came on. This coincided with me filling the gas tank to the brim to round the dollar to be paid. I cleaned the gas tank cap and the tank opening. However, both lights persisted. On the same day, when I turned on the car again, there was a hesitance, a stuttering to come on. Both "Check Engine" and "Trac Off" lights were still on.

The next day, the car wouldn't come on at all. It sounded as the battery was dead. I couldn't even jump start the car. So, I got a new battery from Costco ($59) and put it in. It took 15-20 seconds of cranking to get the car started. Once it was started, the engine sounded fine and the RPM normal. The "Check Engine" light was off. However, the "Trac Off" was still on. I cleaned the gas tank cap one more time.

The next morning, when I turned the car on, there was no problems. It came on instantly as it used to be, didn't have any warning lights, and drove smoothly.