Check engine, VSC Trac off lights

I am in the same boat w/ you: 2008 Sienna XLE w/ these 3 lights on. I've replaced all 6 coils but lights keep coming back on and staying on. A related post suggested it might be evaporative canister associated with the gas tank, a carbon filter that is fouled w/ gas and needs replacing. Let me know if you find anything out. Thanks.

I have the same problem 2008sienna all three lights are on how can I fix them.

Same thing has happened this past weekend to our van. 2008 Sienna XLE Check engine, VSC and Trac lights are all on.....

Just took my 2008 Sienna to the mechanic with same issue - check engine, VSC, and track off all were coming on and off together, but intermittently going back off for day or two over the last couple of weeks. They said its a failing ignition coil. $240 fix with parts and labor.

purge valve

Remove positive battery cable, reconnect after 10 minutes. This forces reset of error codes and usually fixes problem.

Here's what happened to us. Fix 1 : Oxygen sensor. Air filter assembly needed because that is where the O2 sensor was located. That fixed the problem for 1 month. Approx $800. The van started running rough and kept getting worse. HOWEVER, I went around a corner at 30 mph to merge onto a freeway and it ran better than it had minutes before. Fix 2 : Front ignition coil replaced. Mechanic said that the running rough and then better was because of how the wires were sitting. When I went around the corner it jostled them into a better running position. That fix was last week. $400.

I started having the same problem with my Toyota sienna 2015, ever since I got stuck in sugar sand in 2019, all 6 coils were replaced because coil #1 was misfiring, also the alternator and serpentine belt were replaced. It ran good for about 6 weeks, then again TRAC off and engine light comes on. I brought it to the Toyota dealership and I was told probably will take 24-36hrs for a tech to find out the problem which came to $3k, No thanks I said. I notice that every time I drive off asphalt, TRAC off and engine light come on.

I have a 2009 Sienna and when I got the Check engine light and VSC lights on and vehicle would shudder, the first check was the gas cap. Opened it and reinstalled to one click. Warning lights off, then on intermittently. Ultimate diagnosis? Mouse next under engine cover and the mice had been chewing the housing on the wires in the wiring harness to the spark plugs was causing a misfire. Wiring harness replaced. No warning lights.