ALLWiTE2JZ

So I've been having this problem for about a month or two now. What happens is my check engine light decides to come on and then turn off before I have a chance to get it scanned. It comes on for a couple minutes and then turns off again. Today, it came on and stayed on all day and when I was coming home it turned off again on its own. This is getting on my nerves lol I want to know what the hell it is getting set on/off for? It doesn't happen all the time, only every so often. When it stayed on all day today, I headed over to AutoZone and when I told them I needed an OBD-I scanner since my SC300 is a 94, they said they don't do OBD-I, they only do OBD-II (which is bullshiit). So I STILL couldn't get it checked. I am about to buy my own OBD-I scanner so I don't have to rely on other people to do it for me. But anyway, do you guys have any idea what is going on with my check engine light? Is this common for a 94 SC300?

O. L. T.

iTrader: (17)

Doesn't matter, the scanners they have and you'd buy aren't capable of reading the computer. Those scanners rely on a light to be on, but Lexus computer scanners read the actual computer fault log and tell you what it logged when the system threw the light, why, etc. With an intermittent problem if you are lucky enough to catch the light on it might not be a bad component you can replace not knowing which part it is before it fails and the scanner only giving you a general area. So, take it to Lexus and bend over for a diagnostics charge, or wait until you are on the side of the road.

If you want to see what a (was then) $2500 Snap-on scanner will tell you about your early model SC, look in my gallery for my snap-on pics from when I had my big scanner.

It still isn't even close to what the Lexus computer will tell you because it cannot read the logs.

ALLWiTE2JZ

Okay, so what you are saying is just go to Lexus to get it checked? Any idea how much it costs just to get them to look at it? Probably a fortune, I'm sure. Can I take it to a Toyota dealership and get them to look at it for cheaper possibly? I just don't understand what could make a check engine light turn on/off with the car continuously running and the car not even being turned off. I've never experienced this kind of check engine light symptom before so that is why I am curious.

O. L. T.

iTrader: (17)

Is it a constant flash that looks consistent or patterned? If so it's giving you a code and if it is doing it under driving conditions it is USUALLY the torque converter code warning you about a problem in the tranny, BUT it can be the AC system as well. You can obnviously save money if a cheap scanner picks up on the code by sheer luck, but the actual log in the ECU has some really nice info in there most of the time. Make sure the computer/scanner at your dealer is newer and up to date so you get ecu logs.

ALLWiTE2JZ

No the check engine light doesn't flash at all, it will just randomly turn on and off on it's own when driving down the road under normal driving conditions. I don't do anything but drive my car and it decides to randomly come on. It isn't flashing like a strobe light or anything. I was just saying it turns on/off at random times every so often. I just want to get the code and then ask around about what the code means because I'm really not trying to pay Lexus or Toyota a shiitload of money to just LOOK at my car. I'm sure I can just get a OBD-I scanner and when the light comes on, hook it up and read the code right? Then I can just ask you what the code means because I'm sure you have a list of all the codes somewhere right?

99SC42

iTrader: (44)

You have an OBD1 so the scan tool won't do you any good you had to jump E1 and T1 to get the code. GL

Tyrone Alf

What the hell is this guy talking about?? He probly looks like this crazy ***.

6SOARER

iTrader: (20)

^^^^ +1 Only vehicles that are 96 and later are OBD2 compliant and can only be checked with a scan tool. Jump the two terminals that QUICK mentioned and see if thee CEL blinks. If the CEL blinks, than theres your DTCs..

Gspec

I use the Snap-On "Brick" at my shop all the time on my car....OBD1 SC300....Works like a charm...(My CEL has always came on and stayed on however) I didn't realize that OBD1 SC ECU's logged history codes...

ALLWiTE2JZ

Me either, I guess I will take my SC to Lexus or Toyota and get them to look at the ECU logs if this happens again.

818_sc4

iTrader: (8)

Well if it keeps coming on and off i would just take it to dealer to look at ECU logs as mentioned above but if it stays on all you need is a paper clip.. Jump the diagnostic port under the hood.. i did and i got my code first set of blinks is the first digit of the code and second set is the second digit. and then a pause then all over again.. make sure when u jump it keep the ignition in the ON position, and stick one side of the paper clip in the te1 port and the other side in the E1 port all ports are digaramed under the cover of the diagnostic port.. heres a link to more instructions and code definitions. http://us.lexusownersclub.com/forums...howtopic=37260

lexdud

Try this:

http://www.troublecodes.net/Lexus/

O. L. T.

iTrader: (17)

From my '92..........

99SC42

iTrader: (44)

OK so where do you plug it and read the codes? I know Infiniti even 91 had the scan port just like OBD2.

ALLWiTE2JZ

I think you plug it into the thing under the hood on the port that says "DIAGNOSIS" on a 2JZ-GE motor with OBD-I...