Check engine light went out by itself?

[nyk438]

Check engine light was on a few weeks ago, and I haven't been driving the truck since then and I went to check the fluids and some other things and pull the code of the truck and when I turned the truck on and had it running for a little while and I looked on the dash the light had gone off. The truck drove the same as it had there was no difference when the light was on.

How do I check the engine light sensor to figure out if it's faulty or what?

Thanks,

Nick


--91' FJ80

 

[Scamper]

If you have a scanner(good investment if you do your own work), just plug it in and look. No codes = no light.

If not, the only lame thing I can think of is to pull the bulb and check it (assuming that's what you're asking about).

 

[tarbe]

Yea, mine did that, too. Lasted about 500 miles! Don't get too excited....odds are it'll be back.

edit: just noticed your sig...you have a '91...my comments may well not apply to you.

 

[NorCalDoug]

I had that happen on my '94 quite a few times. It'll be back.

 

[drexx]

09Apr2005 (UTC +8)

Maybe what turned it on in the first place was simply a loose gas cap?

The OBD computer will turn the Check Engine Light off if it senses the gas cap is sealed after three consecutiive engine on/off cycles that lasts for at least 15 minutes each.

 

[nyk438]

I'm hoping it's the gas cap.. I thought that the when the light went on that one of my O2 sensors had burned out. I talked to my dad the PO and he said that unless it was in the normal tuneup or stuff done at the dealer than he never had a mechanic do it specifically. First time ever for this light to come on in 14 years...


Now that I think of it, I had gotten gas at least 3 or four times and had driven from San Antonio to Austin and back with it, while the light was on.

 

[lx450landcruiser]

my vote it its O2 sensor mine went out and the light came on i pulled code turned it off but didnt change it 500 miles down the road still didnt come on. 2500 miles down it poped on and wouldnt go away. so i had to replace. sounds like the start of an O2 sensor going bad

 

[Cruisin'Carolina]

You don't have to pull the dash to check the light, it should light up momentarily when you start or just turn the key on.....

 

[SAS]

09Apr2005 (UTC +8)

Maybe what turned it on in the first place was simply a loose gas cap?

The OBD computer will turn the Check Engine Light off if it senses the gas cap is sealed after three consecutiive engine on/off cycles that lasts for at least 15 minutes each.

IluvIH8mud!

Wife came home and said "the check engine light came on". Oh crap! Surfed Mud, found this thread. Couldn't be that easy, right?

Asked if she had bought gas recently...yep. Checked the gas cap--she hadn't made it "click" when she capped it after the fill-up. I made it click. Took a short trip, with anticipation to do it three times, and the light went off after 8 minutes.

Too sweet! Thanks, IH8mud!!!

(please don't tell me thats a different secret trick, and now the tranny's going to fall out )

 

[Gumby]

On a 91? I don't think it has a gas tank evap monitor. Could be a lot of things including a slow O2. I doubt it was the gas cap.

There is no "engine light sensor" on that model either. An OBDII can tell if the light is out, but a 91 can't. If the light comes on when you turn the key on, then the bulb is good.

When it comes back, check the codes.

SAS- I don't think you have an EVAP monitor either. The only 1994 Toyotas that were running OBDII were the Camry(1MZ-FE 3.0L V6) and T100 pickup (3RZ-FE 2.7L four). It sounds like you had a EGR or O2 sensor that had already had one or two drive cycles of clean running before you started it again.