VCS and Check Engine Indicators

[utah33]

Today my VCS and Check engine indicators came on in our 2000 Toyota Avalon. Anyone have this happen before? Suggestions on where to begin would be appreciated.

Thanks

[Maxemily]

The VSC light often comes on with the Check Engine light. Start by getting the code pulled from the ECU, which can only be done by interfacing the OBD connector with a scan tool.

Most common problem: loose fuel cap

[utah33]

Thanks

Had the codes read. Came up with a P0171. Fuel System For Bank 1 was to lean. Guy at the autoparts store suggested pulling the A/F sensor cleaning it and seeing if this fixes it. If not a new A/F sensor runs $300.

Having trouble disconnecting connect to A/F Sensor. Must be a release or something, but can't seem to get it disconnected? Any Suggestions. Any speacial tool required?

Thanks

[BadChicken]

You need to replace your Mass Air Flow sensor located on the air box. A P0171 codes is Lean Fuel Trim. Takes about 2 minutes to replace. 2 screws and 1 connector. This is a very common problem on the V6's

[csaxon]

Have you had work done recently? Did you replace an air filter? Look for loose or disconnected air/vacuum hoses and check your air filter box is sealed around the edges. If they're ok then: Badchicken is correct, but sometimes a simple cleaning can work wonders and save money.

Most of the time when PO171 is stored the wires of the mass air flow sensor need cleaning.
Use an electrical contact spray cleaner or brake cleaner with a Q-tip to clean the wires. Be careful not to damage them

If you have a scan tool check the fuel trim data before and after cleaning the MAF sensor. That way you'll now if the repair was effective. Without checking the data you'll have to wait and see if CEL returns. That may happen right away or it may take a number of drive cycles if the sensor is borderline.

If cleaning makes a difference but fuel trim is still correcting for a lean condition chances are you'll have to replace the sensor.


Try that and erase the code .

[csaxon]

Some examples:CLEANED

[IMG][/IMG]

[csaxon]

DIRTY

[IMG][/IMG]

[foompla]

i wouldnt touch it with a q tip.... jmo.

[gbaoyn]

you mean the sensor has to be taken off to clean?or just disconnect the connector to clean.
Thank you.

[csaxon]

Yes, 2 screws.

[utah33]

csaxon,

Is a scan tool the same as the OBDII or something different? How do I check the fuel trim data? What does the acronym MIL stand for?

This sounds like a logical solution.

Thanks everyone for you input it has been a while since I have visited.

I've checked the A/F ratio sensor in Bank 1 and Bank 2, they both seem OK per the check the manual called out. I also checked the Secondary O2 sensor near the cadalytic converter it also seemed OK? I check the MAF sensor per the Manual and it checked OK? I also disconnect the coolant sensor check it and it seemed OK? After each of the above items were checked I reset the code by disconnecting the negitive battery cable for a brief time and reconnecting. All with the exception of the coolant sensor the light came back on the next time the vehicle was driven. With the coolant sensor my wife drove over a hundered miles before it came on again?

Just a little rundown on where I am at.

I will post any more finding or fixes

[csaxon]

OBD II (ONBOARD DIAGNOSTIC SYSTEM Version 2) is designed to detect emission problems. The Check Engine light will come on anytime emissions exceed federal limits by 50% on two consecutive trips, or there’s a failure of a major emissions control system.

A diagnostic trouble code is then stored in the vehicle’s powertrain computer. Later, the code can be read using a scan tool to determine the nature of the problem.


I used an older term MIL (Malfunction Indicator Light). CEL (Check Engine Light) is the new term. They mean the same thing.

A scanning tool is hooked up to the onboard diagnostic port (obdII) to read the codes. All obdII compliant scan tools will work with your car. They range in price and capability from $50 to several thousand dollars.

The higher the cost the more info and testing capabilities.

Get your codes checked again to be sure it's the same problem. If it is I'd try cleaning the MAF.

Good Luck

[ToyotaAvalon00]

hey i have an avalon and like the Engine light WONT go off and i cant figure out what it iss.. do u guys think it could be the mass airflow snesor too? its a 00 analon LE idk it has cloth seats and the v6 4 cam engine the 3000 series engine.. any help?? and also .. i wanna disconnect my traction control How would i go about doin that?

[jdmeridith]

...and then go back through this thread to find the answer. Without a code that is a BROAD question with innumerable answers.

By the way, a code reader can usually be rented at no charge from your local parts store.

[utah33]

Cofirmed Fix, Thanks to csaxon's advice.

Cleaning the MAF Sensor as described by csaxon fixed my problem. Hallelujah!!!

Thank You csaxon and everyone else that had input, it was all helpful.

The photo were great and very helpful. I had taken off this sensor before and did some ohm checks, but didn't realize that the sensor wires were up inside that tube (see photos)

After reading csaxons advice on 3-6-06, I took off the MAF Sensor and took it to work.

I am a electronic technician and had access to Q-tips and Electronic Cleaner and did just as csaxon said.

As of today, the VSC and Check Engine Light has not came on again. I wanted to give it a long run to confirm the fix. By George I believe its fixed.

Thanks again and I hope this thread helps someone else. Thats what its all about isn't it.