Odd CEL activity

Joined
Apr 14, 2011
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542
Location
Rocklin CA
So I have owned my 1994 FJ80 for probably 3 weeks now, and have been clearing this CEL code quite often. Here's how the story goes....

I buy this truck, the prev. owner has 0 maitenance records and knows pretty much nothing about it. The truck was given to her by her father (still in his name) and she needs it gone cause it gets 13mpg. Its a great truck, runs strong & has 181,000 on the clock. Only issue so far is the Oil Pressure gauge isnt responding, thats a different story.

So I buy the truck and drive it the 30 miles home without issue. That night I parked it for about an hour, then took the wife on a ride to show it off and as soon as I get on the freeway, not 10 miles later my CEL pops on.
Of course I am concerned, and of course the wife notices and starts with the questioning... That night when we got home I researched the CEL codes and how to pull them on OBD1 (which I assume I have since i have a '94).

Since that day, the CEL has come on repeatedly but only if I get on the freeway, but it gets alittle wierder.

I have gotten into the habit of just pulling the negative battery cable whenever I stop again, once the CEL first comes on. It will usually stay off for days, depending on wether or not I have to jump on the freeway. But yesterday I had to drive to the Bay Area, 240miles round trip. I get on the freeway early in the morning, and goto pickup a buddy of mine. Of course the CEL pops on about 10 miles into my trip. But I cleared the light when I reached my friends, and after we left his house we jumped back on the highway and continued another 120 miles straight freeway, without the CEL light comming on at all. We reached our destination and when it was time to come home, we got in the truck, and not 10 miles on our way home, the CEL pops on... i quickly pull over and remove the negative, jump back in the truck and continue on the rest of the 100+ miles home without incident.

I am going to pull codes, but my buddy has a OBD1 reader he said he'd let me use. I might try that before I start jumping pins and reading morris code. I was curious if this type of activity could be something simple like a bad gas cap (i hear a HISSSSS everytime I goto the gas station). Or if it sounds like something alittle more difficult?

Thanks in Advance,
-Brian
 
Joined
Feb 13, 2010
Messages
396
If you figure out how to pull codes with a reader, please let the rest of us how you did it since others might find that useful. I'm under the impression that you can only pull codes by jumping the terminals and watching the lights flash.
My truck does something similar. I've pulled the codes and it's the 401. I was going to put in a new EGR vacuum component but I haven't gotten around to it. My light goes off after a couple of on\off cycles so I quit worrying about it.
 
Joined
May 31, 2005
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My friend has a reader, he says it will do OBD1. If it doesnt I will resort to pulling codes.

"Resort" to pulling codes? :confused:

You're being silly. Takes under a minute and no special tools. Heck, you could do it while you're gassing up, just like checking the oil.

Does something about the process sound mysterious to you? Spill it and we'll clarify.
 
Joined
Apr 14, 2011
Messages
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Rocklin CA
It took a while to find the instructions on retrieving codes for the OBD1. I found it in the FAQ here at MUD, but there were conflicts in the procedure. One tutorial said to short 2 pins, and another tutorial says to short 2 different pins for the same result.

Then I downloaded a Factory Service Manual for the 1996 and it shows 2 completely different pins (but I now come to realize the '96 is OBD2).

So I guess that is whats been holding me back from counting blinking lights. But if you guys are saying OBD1 scanners dont work with FJ80's maybe I'll spend the day under the hood tomorrow.
 

NorCalDoug

problems solved daily...
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uhhhh...duh...Northern CA
95 through 97 are ODB2.
93 and 94 are ODB1.

the FSM for the 96 your downloaded will help you for most of what you may need to do, but not everything. See if you can find a FSM for a 93 or 94.

I think you're gonna be stuck counting the flashing lights.

Not that I can help you too much with the CEL/MIL issue, but I'm local to you and may be able to give you some general pointers if you're interested.
 
Joined
Jan 29, 2010
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Seattle, WA
Just so you know: you don't HAVE to clear the CEL just because its on. Its most likely something very minor. Resetting the battery also wipes the memory of the ECU, which can cause a rough idle and poor mileage, among other things. I would also recommend getting the code asap if it is bothering you. We cant help you until we know what the code(s) are.
 
Joined
Apr 14, 2011
Messages
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Rocklin CA
Yeah i dont like resetting the ECU so often, so i will pull the code and get to business. The biggest thing is California Smog, i have to go get the truck tested and a CEL is an auto-fail.
 

NorCalDoug

problems solved daily...
Joined
Oct 27, 2003
Messages
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uhhhh...duh...Northern CA
Yeah i dont like resetting the ECU so often, so i will pull the code and get to business. The biggest thing is California Smog, i have to go get the truck tested and a CEL is an auto-fail.

aaahhhh...so you bought the rig and agreed to smog it yourself instead of making the previous owner smog it before the sale?

yes, the CEL is an auto-fail.
 
Joined
May 31, 2005
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aaahhhh...so you bought the rig and agreed to smog it yourself instead of making the previous owner smog it before the sale?

Whoa.

Missed that. That type of transaction's not even legal in Cali. anymore, is it?
 

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