My check engine light came on and this message appeared above my odometer. I read my owner's manual and it says the Vehicle Stability Control system may be malfunctioning and "take it to the dealer." Can anyone provide me with more information -- visa vis -- best case vs worst case scenarios. Thanks, DeeBop

@DeeBop Toyota has designed the VSC to automatically disable when a CEL is triggered. It is doubtful there is a problem with the VSC system itself. You need to have the vehicle scanned for trouble codes and figure out what the actual issue is. Once the issue is corrected, you can clear the code(s) and the warning lights should disappear.

Thanks Top Notch IN --- Please pardon my inexperience, you mention the VSC is automatically disabled when a CEL is triggered. What's a CEL. I do have a scanner, so I can get the code(s) ... and clear the warning. Anticipating your answer with much appreciation. DeeBop

@DeeBop CEL/MIL = Check Engine Light / Malfunction Indicator Light (same thing). Yes, use your scan tool and find out what codes you have. It's likely the VSC lamp and warning are just because of the CEL. It won't hurt the VSC system if you drive the car unless there's an actual stability control issue. You can reply again with the codes if you need any further assistance and I will try my best to help. Sometimes the codes on these vehicles don't clearly point out the actual problem. Good luck!

Whats the issue with the car other then the VSC? Is the car starting and driving normal? Has the car been sitting?

Thanks Top Notch ... I put the code scanner on my GS 430 this morning and it came up as PO 136 (O2 sensor). Which is weird because the car skid (VSC) warning is what showed up on the dash. Car handles perfectly. DeeBop

Hi IBIDU -- Yes. Near as I can tell the car has been sitting for about 4 months or so before I bought it. I drove it for 3 days before the VSC Check & skid warning icon showed up on the dash. The car handles perfectly.

This morning I OBD scanned it. The code came up as PO 136. I understand this is an O2 sensor issue. It doesn't make sense. DeeBop

P0136, O2 circuit (Bank 1, Sensor 2). I believe it's the downstream sensor on your passenger side exhaust. Maybe you have carbon build up, maybe just an original O2 sensor needing replacement. I would clear the code, buy a tank of high quality premium fuel, and a can of high quality fuel injector cleaner and see what happens. If the code continues to come back, but the car runs well, you may need a new O2 sensor. I buy mine from RockAuto. Only use OEM (from Toyota) or Denso (RockAuto). Avoid no name sensors.

For what it's worth, I've had to replace that sensor twice in the last few years on my 2007 GS350. Carbon build up contributed to a dirty sensor. Ironically, no issues on the driver's side downstream sensor.

Also, when was the last time your spark plugs were replaced with genuine Toyota (Denso) plugs?

3GS when they sit for awhile they throw error codes and usually they go away. I would drive the car, give it a few days and if the code doesnt go away on it own. Then you can replace that o2 sensor as 93scmax suggested, by using only denso brand or oem.

Thanks 93SC MAX ... I am going to pick up a can of fuel injector cleaner today -- and give it a try. Best regards, DeeBop

Ibidu 1 I appreciate your input. As it turns out, I made an appointment at my local Lexus dealer for Monday, June 24. They are going to...

1. replace the timing belt
2. replace the water pump
3. Find out where the oil leak from behind the camshaft cover is coming from (on the passenger-side, cylinder bank)

Last Friday, I filled the gas tank for the first time with premium fuel. (The gas originally in the tank when I bought the car had been sitting there for at least four months -- wintertime.) Anyways, I may have not tightened the gas cap sufficiently. I am going to top of the gas today and add fuel injector cleaner. Then wait and see what happens.

I am a fan of Toyota -- and by extension Lexus. I have an 05 Toyota Avalon Limited with 307,000 miles (496,000 km) on it. I bought it in Chicago 17 years ago.

Personally I would save my money and take it to a lexus/toyota specialist instead of paying high prices for the dealer. No need to pay big bucks and buy parts and labour from the dealer, for the water pump.

You can buy aisan brand from rockauto, aisin is the supplier for toyota for cars. You can even see them grind off the toyota badge on the water pumps.

I will check Rock Auto out. Thanks for the tip.