lrh512

Hello!

Can someone help me come up with reasonable investigation steps for fixing my 2004 RX330 with 141k miles?

The check engine, VSC, and Trak off lights come on (and go off) intermittently. Now, they are "on" more than "off." The last time they came on, it coincided with hitting a pothole. As far as I can tell, the car usually runs fine when the lights are on, but I did have trouble once in the pouring rain going 60 mph on the highway when the car began to run rough and the rpms reached 3000. I believe that the warning lights stop the car from going into overdrive, but I had never noticed a problem before. I usually do not drive on the highway, though.

I took the car to the dealer, and they replaced the gas cap and said maybe I had some bad gas in the tank. I recently switched my gas to 89 octane, but the dealer said that shouldn't be a problem. (Nonetheless, I am now putting higher octane gas in the car.) I was told that if the gas cap replacement didn't fix the problem, I was looking at a very expensive repair.

Since the problem is intermittent, could it be a wiring issue? Are there other less expensive problems that are equally likely as a "bad knock sensors"?

Thanks to those of you who can share some insight! My sense is that the dealer needs to explore a little more before rolling out the $1000+ repair, but I will need to go back with more knowledge than I have now.

Wht95scort

Your first code is for a knock sensor. When they go bad it will cause drivability issues with the trans. The job requires removal of the upper and lower intake.

The second code is for your evap. Common is a loose gas cap but could be other things such as a bad vsv or hose. further diagnosis would be needed to find your fault.

dganapol

Do a search and you will find it is the brake light switch on the petal.

David

RX3302004

I have a 2004 330 and it's had the brake light switch replaced many times. Prior to each replacement the dash has numerous warning lights displayed.

lrh512

Thanks everyone. I'm struggling with the intermittent nature of the problem. The lights go "off" and I keep hoping that it's permanent, but then a few days later, they reappear again.

The car definitely has driveability problems when the warning lights are on.

The brake lights are working with no issues. I replaced the gas cap. When the 3 warning lights are on, the car operates at close to 3000 rpms at high speeds and sometimes lags when accelerating.

I guess the next step is to replace the knock sensors and hope that does the trick. If anyone has any other thoughts ...

Thanks again!