Checking Codes on a 91 4runner?

Fo by Fo · 11-29-2006, 08:58 PM

Hey guys, I got a check engine light on my 91 4runner and to my dismay autozone can't check it because its not OBDII. I'm sure I'd have to pay the dealer an arm and a leg just for them to take 30 seconds to check the code. Is there a way I can check it myself? I'm assuming my truck is OBDI, do I have to just go out and buy the scanner thing? Let me know how you guys check your codes, because check engine lights drive me nuts.

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callmej75 · 11-29-2006, 09:03 PM

Quote:

Originally Posted by Fo by Fo

Hey guys, I got a check engine light on my 91 4runner and to my dismay autozone can't check it because its not OBDII. I'm sure I'd have to pay the dealer an arm and a leg just for them to take 30 seconds to check the code. Is there a way I can check it myself? I'm assuming my truck is OBDI, do I have to just go out and buy the scanner thing? Let me know how you guys check your codes, because check engine lights drive me nuts.

Theres a diagnostic box on the passenger side fender under the hood...its labeled on top of the box. Take a paper clip and make it into a U shape and put it into the TE1 and E1 holes...these slots are labeled under the cap in a diagram. Then get in and turn the ignition switch past ACC to on and watch the check engine light blink. If there is a short pause between blinks then its a 2 number code. The codes will cycle through and start all over so have a pen and paper handy.

toyota_mdt_tech · 11-29-2006, 09:03 PM

Quote:

Originally Posted by Fo by Fo

Hey guys, I got a check engine light on my 91 4runner and to my dismay autozone can't check it because its not OBDII. I'm sure I'd have to pay the dealer an arm and a leg just for them to take 30 seconds to check the code. Is there a way I can check it myself?

Yes, but I dont want you to lose an arm or a leg. Have you tried Pep Boys? I know it will take over 30 seconds to go into Autozone and listen to the guy tell you he cant do it.

reggie 00 · 11-29-2006, 11:08 PM

Quote:

Originally Posted by toyota_mdt_tech

Yes, but I dont want you to lose an arm or a leg. Have you tried Pep Boys? I know it will take over 30 seconds to go into Autozone and listen to the guy tell you he cant do it.

I know you are making a point. But you have to admit that not all dealerships or dealership techs make the effort you do. And some people might have a justifiable negative opinion on the whole going to the dealership subject.

if you know just say so. when you do like above more than the person who originally posted that got your ire up suffers from your post.

If you don't care for the negative dealer comments PM them and change their mind.

I have read almost every post you have done in the last few weeks and have learned quite a bit, and will hopefully continue to glean some info from your experiences. You have posted some very useful info. Don't muddy the waters by trying to but heads with the haters.

sorry for the rant , back to the regularly scheduled program.

Fo by Fo · 11-30-2006, 04:50 AM

You have to admit that most dealerships are the most expensive places you can go to have service done on your truck. I do all the work on my truck myself but occasionally go to the dealership to order parts. I'm confused by what your post meant, but when I go to the dealer they are usually less than helpfull if I have questions. I see that you work for a dealer but don't be offended by my post and take it personal as I was not talking about you or the dealership you work for.

Fo by Fo · 11-30-2006, 04:55 AM

Quote:

Originally Posted by callmej75

Theres a diagnostic box on the passenger side fender under the hood...its labeled on top of the box. Take a paper clip and make it into a U shape and put it into the TE1 and E1 holes...these slots are labeled under the cap in a diagram. Then get in and turn the ignition switch past ACC to on and watch the check engine light blink. If there is a short pause between blinks then its a 2 number code. The codes will cycle through and start all over so have a pen and paper handy.

What do you mean by number 2 code? Is that a code that starts with the number 2? Also after the first 2 blinks what else will the check engine light flashing tell me? I'm not sure I'm clear on this whole process of reading the codes.

reggie 00 · 11-30-2006, 07:59 AM

I think he means it will be a two digit code Like 10 or 25. the first set of blinks will be the first digit 1 the pause then the next set will be second digit 7.

callmej75 · 11-30-2006, 08:02 AM

Yes...it will blink twice...then short pause...then maybe blink 5 times...that is read as code 25. Now...keep watching it because the codes repeat themselves and be sure you are reading the code correctly. There will be a longer pause in between blinks when the code is finished. Like this...

Blink blink...blink blink blink....................blink blink blink

That would be a code 25 and 3 just for an example. Best way I can explain it..

4Crawler · 11-30-2006, 08:03 AM

How to check codes:
http://www.4crawler.com/4x4/CheapTri...CheckConnector

toyota_mdt_tech · 11-30-2006, 09:09 AM

Quote:

Originally Posted by callmej75

Yes...it will blink twice...then short pause...then maybe blink 5 times...that is read as code 25. Now...keep watching it because the codes repeat themselves and be sure you are reading the code correctly. There will be a longer pause in between blinks when the code is finished. Like this...

Blink blink...blink blink blink....................blink blink blink

That would be a code 25 and 3 just for an example. Best way I can explain it..

Code 25 is a lean condition. Make sure its not accompanied by a code 26, or its spendy. Means a cylinder imbalnce on power, ie compression varying more than 14 PSI

Fo by Fo · 11-30-2006, 05:25 PM

So I checked the code today with the paper clip, That was awesome! I couldn't believe something so simple worked. I came up with a code 71 witch is the egr system. A dealership had told me before that it was either the egr modulator or the egr vacuum switching valve (VSV) I have already replaced the modulator and the light is still on, but before I just start buying more parts I was wondering if anyone else here has had any expierience with this code and what it was. I looked in my manual to find my VSV a month or so ago and couldnt find it. Thanks for the help so far guys.

callmej75 · 11-30-2006, 06:02 PM

Quote:

Originally Posted by Fo by Fo

So I checked the code today with the paper clip, That was awesome! I couldn't believe something so simple worked. I came up with a code 71 witch is the egr system. A dealership had told me before that it was either the egr modulator or the egr vacuum switching valve (VSV) I have already replaced the modulator and the light is still on, but before I just start buying more parts I was wondering if anyone else here has had any expierience with this code and what it was. I looked in my manual to find my VSV a month or so ago and couldnt find it. Thanks for the help so far guys.

Check and see if your actual EGR valve is operating correctly. One way to do it, locate the EGR valve on the passenger side of the intake plenum. There is a vacuum line that attaches to the top of it. Start it up, take that top vacuum line off the top of the egr, but leave it attached to the egr valve. Now suck on it, if the motor dies, it is good, if not, you found your problem!

Fo by Fo · 11-30-2006, 06:14 PM

How much suction does it usually take to make the motor die? I sucked as hard as I could (hahaha I can't help but laugh) but at the most the engine just seemed to slow down a bit, but not die.

ScubaDuck · 11-30-2006, 06:17 PM

Forgive me if I'm being Captain Obvious, but you did clear the code right? (By pulling the neg battery cable or pulling the ECU fuse) It just concerns me when you say "still on" as the code won't go off till you clear it. When the code comes back on that you know you have not fixed the problem.

Good luck-

-Scubaduck

callmej75 · 11-30-2006, 06:17 PM

Quote:

Originally Posted by Fo by Fo

How much suction does it usually take to make the motor die? I sucked as hard as I could (hahaha I can't help but laugh) but at the most the engine just seemed to slow down a bit, but not die.

It takes just a little suction...never correctly measured the lbs/sqin or anything...

Mine slowed the motor way down and died...might have a leaky EGR valve.

callmej75 · 11-30-2006, 06:19 PM

Quote:

Originally Posted by ScubaDuck

Forgive me if I'm being Captain Obvious, but you did clear the code right? (By pulling the neg battery cable or pulling the ECU fuse) It just concerns me when you say "still on" as the code won't go off till you clear it. When the code comes back on that you know you have not fixed the problem.

Good luck-

-Scubaduck

Good point scuba....clear codes like you specified, then drive it for a while til the CEL comes back on. If its a code 71 again, then you know something is definately wrong.

Fo by Fo · 11-30-2006, 06:23 PM

yeah I have cleared it since replaceing the egr modulater and its come back.

Fo by Fo · 11-30-2006, 06:28 PM

I hate to buy a new egr just to find its not the problem, if I remove it is there any obvious visual sign that it isn't working?

callmej75 · 11-30-2006, 06:52 PM

Quote:

Originally Posted by Fo by Fo

I hate to buy a new egr just to find its not the problem, if I remove it is there any obvious visual sign that it isn't working?

I would think now...it will still throw a code if removed. Go to a junkyard and buy one. They are over $100 new, but you could maybe get lucky with one at a junkyard.

Fo by Fo · 11-30-2006, 06:55 PM

good idea, are they pretty easy to remove?

toyota_mdt_tech · 11-30-2006, 07:43 PM

Quote:

Originally Posted by Fo by Fo

So I checked the code today with the paper clip, That was awesome! I couldn't believe something so simple worked. I came up with a code 71 witch is the egr system. A dealership had told me before that it was either the egr modulator or the egr vacuum switching valve (VSV) I have already replaced the modulator and the light is still on, but before I just start buying more parts I was wondering if anyone else here has had any expierience with this code and what it was. I looked in my manual to find my VSV a month or so ago and couldnt find it. Thanks for the help so far guys.

Yes, a code 71, no EGR. Did someone swap some vacuum hoses around? There will be 3 small metal pipes arranged in a triangle about #3 spark plug area. The vacuum hoses going to them shall be marked. Tope one must be #3, bottom one on the rear is #5, bottom right is #6. There is a little air suction, that will have #4 vacuum hose going to it. Others goes to the gas filter (which isnt a fuel filter) and that is basically a vacuum tree on the intake (vacuum port wiht a filter in it) and those will be marked #0. If you already replaced the modulator, I'd get a vacuum pump and try to open the EGR valve. Or run the engine and rob a vacuum source and hook it to the ERG and see if the engine stalls or almost. Technically, at idle, it should stall. Now one way to eliminate the light would be to unplug the EGR gas temperature sensor and short the wires together. But EGR is nice to have, it does help reduce ping. A 1991 with the EGR temp sensor, you must have a California model emissions, right? Oh. fo by fo, sent you a PM, thansk for the kind workds on my 2004 Cargomate too!

An EGR valve is spendy, and prety easy to replace. Holler if you need more help.

callmej75 · 11-30-2006, 07:43 PM

Quote:

Originally Posted by Fo by Fo

good idea, are they pretty easy to remove?

4 small bolts on the plenum, 2 large nuts holding the pipes onto it. Disconnect the vacuum lines. Not much to it. I would think if your egr valve was going out, then you may be running crappy?

callmej75 · 11-30-2006, 07:46 PM

Quote:

Originally Posted by toyota_mdt_tech

Yes, a code 71, no EGR. Did someone swap some vacuum hoses around? There will be 3 small metal pipes arranged in a triangle about #3 spark plug area. The vacuum hoses going to them shall be marked. Tope one must be #3, bottom one on the rear is #5, bottom right is #6. There is a little air suction, that will have #4 vacuum hose going to it. Others goes to the gas filter (which isnt a fuel filter) and that is basically a vacuum tree on the intake (vacuum port wiht a filter in it) and those will be marked #0. If you already replaced the modulator, I'd get a vacuum pump and try to open the EGR valve. Or run the engine and rob a vacuum source and hook it to the ERG and see if the engine stalls or almost. Technically, at idle, it should stall. Now one way to eliminate the light would be to unplug the EGR gas temperature sensor and short the wires together. But EGR is nice to have, it does help reduce ping. A 1991 with the EGR temp sensor, you must have a California model emissions, right? Oh. fo by fo, sent you a PM, thansk for the kind workds on my 2004 Cargomate too!

An EGR valve is spendy, and prety easy to replace. Holler if you need more help.

Some have temp senders and some don't...could be the temp sender even? If i remember....that is a different code....don't mark me on that. I kicked at this problem for 4 months one time. It aggravated me to death!

toyota_mdt_tech · 11-30-2006, 08:06 PM

Quote:

Originally Posted by callmej75

Some have temp senders and some don't...could be the temp sender even? If i remember....that is a different code....don't mark me on that. I kicked at this problem for 4 months one time. It aggravated me to death!

Code 71 is insufficeint EGR flow. It wont show excessive like an OBDII rig will. EGR gas temp sensor is onyl on the Cally models, up till about 93, then thye all got it. Cally or not. The sensor isnt bad, it looks for "heat" when its supposed to be on. The sensor is how it sees heat or not. A good way to see if its working while setting in the driveway is to spray some WD40 on the flexible pipe under the valve. Then hold the throttle about 2000 rpms, and about 2 minutes after starting it, you will see it open as the pipe will start to rapidly burn off the WD40 (emits some light smoke). I can get the manual specifics on testing the EGR system if you want to PM fo by fo.

I also might add, I mentioned shorting the EGR gas temp sensor pins, this doesnt fix your problem (inop EGR) it just makes the engine ECU ignore the EGR system. In fact, non cally models had a factory short pin plugged onto the ERG gas temp sensor wire. So it will never set that code again.

callmej75 · 11-30-2006, 08:41 PM

Quote:

Originally Posted by toyota_mdt_tech

Code 71 is insufficeint EGR flow. It wont show excessive like an OBDII rig will. EGR gas temp sensor is onyl on the Cally models, up till about 93, then thye all got it. Cally or not. The sensor isnt bad, it looks for "heat" when its supposed to be on. The sensor is how it sees heat or not. A good way to see if its working while setting in the driveway is to spray some WD40 on the flexible pipe under the valve. Then hold the throttle about 2000 rpms, and about 2 minutes after starting it, you will see it open as the pipe will start to rapidly burn off the WD40 (emits some light smoke). I can get the manual specifics on testing the EGR system if you want to PM fo by fo.

I also might add, I mentioned shorting the EGR gas temp sensor pins, this doesnt fix your problem (inop EGR) it just makes the engine ECU ignore the EGR system. In fact, non cally models had a factory short pin plugged onto the ERG gas temp sensor wire. So it will never set that code again.

Some good info there! Did not know they had the temp senders on all after 93...my bad!

11-30-2006, 08:03 AM	#9 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 7,829	How to check codes: http://www.4crawler.com/4x4/CheapTri...CheckConnector __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs or 35x12.50 MTRs r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club

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11-30-2006, 04:50 AM	#5 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	You have to admit that most dealerships are the most expensive places you can go to have service done on your truck. I do all the work on my truck myself but occasionally go to the dealership to order parts. I'm confused by what your post meant, but when I go to the dealer they are usually less than helpfull if I have questions. I see that you work for a dealer but don't be offended by my post and take it personal as I was not talking about you or the dealership you work for.

11-30-2006, 08:02 AM	#8 (permalink)
callmej75 Contributing Member Join Date: Feb 2004 Posts: 2,932	Yes...it will blink twice...then short pause...then maybe blink 5 times...that is read as code 25. Now...keep watching it because the codes repeat themselves and be sure you are reading the code correctly. There will be a longer pause in between blinks when the code is finished. Like this... Blink blink...blink blink blink....................blink blink blink That would be a code 25 and 3 just for an example. Best way I can explain it..

11-30-2006, 05:25 PM	#11 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	So I checked the code today with the paper clip, That was awesome! I couldn't believe something so simple worked. I came up with a code 71 witch is the egr system. A dealership had told me before that it was either the egr modulator or the egr vacuum switching valve (VSV) I have already replaced the modulator and the light is still on, but before I just start buying more parts I was wondering if anyone else here has had any expierience with this code and what it was. I looked in my manual to find my VSV a month or so ago and couldnt find it. Thanks for the help so far guys.

11-30-2006, 06:14 PM	#13 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	How much suction does it usually take to make the motor die? I sucked as hard as I could (hahaha I can't help but laugh) but at the most the engine just seemed to slow down a bit, but not die.

11-30-2006, 06:17 PM	#14 (permalink)
ScubaDuck Registered User Join Date: Feb 2005 Location: Clyde, CA Posts: 107	Forgive me if I'm being Captain Obvious, but you did clear the code right? (By pulling the neg battery cable or pulling the ECU fuse) It just concerns me when you say "still on" as the code won't go off till you clear it. When the code comes back on that you know you have not fixed the problem. Good luck- -Scubaduck

11-30-2006, 06:23 PM	#17 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	yeah I have cleared it since replaceing the egr modulater and its come back.

11-30-2006, 06:28 PM	#18 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	I hate to buy a new egr just to find its not the problem, if I remove it is there any obvious visual sign that it isn't working?

11-30-2006, 06:55 PM	#20 (permalink)
Fo by Fo Registered User Join Date: May 2006 Location: Arizona Posts: 181	good idea, are they pretty easy to remove?