The wife was driving home when all the warning lights went off on her 2011 RX 350. AFS, ABS, AWD, headlight symbol are all flashing warnings. Plugged my code reader in. No codes in the engine or transmission modules. Did a voltage check and it has 13.7 volts at idle with the lights on. Any suggestions on what else I should check?

 

The gas cap. First step, make sure its tight, and then drive it some.
known to go into limp mode with the evap system compromised. Which can turn on all things you mentioned, I believe.

 

I forgot to mention, I did check that. It was tight.

 

Check battery voltage with the car off.

 

^This.
13.7V sounds a shade low at idle. Shouldn't it be closer to 14.4V? I think you have sulfate buildup in the battery that temporarily caused a couple plates to short.

 

Buy a new battery.

 

These factory Lexus batteries are marginal at best. If yours is original, it is long past its expiration date.

 

I had my factory battery checked six months ago, and it was OK....which surprised me as it was 7.5 years old at the time...it finally died yesterday....having lasted eight years, it probably wasn't a crappy battery.

 

I own a 2010 RX350 AWD and its been solid as a rock. 105K miles and just replaced the ORIGINAL battery with another Lexus OEM one. Also just replaced the Original brake rotors which still had some life in them as well as the rear shocks which finally started leaking a few weeks ago.

 

I think the factory battery lasted about 7 years in the wife's car. Whatever you do, don't buy a battery from Walmart. I've had issues with 3 different Walmart batteries in the last couple of years. I now use Interstate batteries.

 

Problem solved. For those that thought it was a battery issue, it wasn't. 13.7 volts at idle with the lights on is more than enough voltage. Gas cap an issue? I tightened the gas cap and when that didn't work, I replaced it. Not the problem. Finally had to have the dealer plug the diagnostic computer into the car. Rodent chewed through the RF wheel speed sensor wire where it runs inside the fender. I figured it was a sensor since the three warning lights (ABS, AWD, and AFS) all went off at the same time. I thought it might be a speed sensor, but I wasn't sure as I didn't know the AFS worked off the speed sensor and I didn't want to throw parts at it.

 

Wow good to know. Makes sense why you didn’t get any codes, needed a deeper level scan tool to get to those modules.

 

Glad you found your issue!
do you mind sharing what you ended up paying for the diagnostics and repair?

 

If you park in a garage at home it is time for mousetraps. There are also rodent repellents you can place around the engine compartment.