EGR code 71

Alex 400 · 04-29-2008, 11:16 AM

so my Check engine light kicked on and when i pulled the code, it was code 71. it also said that it was a california car code. but my truck was bought here in washington, as far as i know. for those that have had this code, what was turned up being wrong?

thanks guys!

thook · 04-29-2008, 11:23 AM

I think CA vehicles are the only ones with gas temp. sensors, so see if yours has one. It would be on the side of the EGR valve body. If not, you should have a bimetal valve that controls the temperature at which valve is allowed to open. On the back of the upper intake manifold, I believe. It's been awhile since I've had to look at my 3.0 to fix anything, but I believe that's where it is.

The bimetal valve will have two, small vac lines going to it and a vent cap.....no electricals.

anotherjeff · 04-29-2008, 11:34 AM

Deja Vu!!

Alex, you posted the same question one year ago!!
http://www.yotatech.com/f116/egr-code-71-a-119293/

Has your CEL been on for the past year?

Alex 400 · 04-29-2008, 11:35 AM

Quote:

Originally Posted by thook

I think CA vehicles are the only ones with gas temp. sensors, so see if yours has one. It would be on the side of the EGR valve body. If not, you should have a bimetal valve that controls the temperature at which valve is allowed to open. On the back of the upper intake manifold, I believe. It's been awhile since I've had to look at my 3.0 to fix anything, but I believe that's where it is.

The bimetal valve will have two, small vac lines going to it and a vent cap.....no electricals.

i do have that temp sensor on the side of the EGR valve. if one of those was to crap out, would that trip the code?

4Crawler · 04-29-2008, 11:40 AM

Quote:

Originally Posted by Alex 400

i do have that temp sensor on the side of the EGR valve. if one of those was to crap out, would that trip the code?

Yes, the ECU logic is that if it commands the EGR valve to open, after a period of time, the temp. sensor should indicate a temperature inside the EGR valve above some minimum value to tell the ECU that hot exhaust gas is indeed flowing through the valve. If not, the ECU assumes with the sensor or the valve is not working.

Alex 400 · 04-29-2008, 11:43 AM

Quote:

Originally Posted by anotherjeff

Deja Vu!!

Alex, you posted the same question one year ago!!
http://www.yotatech.com/f116/egr-code-71-a-119293/

Has your CEL been on for the past year?

no actually! it turned off for about 7 months then the light would come on everyonce and a while, but it was never on long enough for me to pull the code, i had a little time so i just ran out and pulled the code because the light was on. the reason why i am trying to jump on it now because i am tryign to get the truck all ship shape before heading off to college. got a few long drives ahead.

Alex 400 · 04-29-2008, 11:45 AM

Quote:

Originally Posted by 4Crawler

Yes, the ECU logic is that if it commands the EGR valve to open, after a period of time, the temp. sensor should indicate a temperature inside the EGR valve above some minimum value to tell the ECU that hot exhaust gas is indeed flowing through the valve. If not, the ECU assumes with the sensor or the valve is not working.

ok so i did test the egr valve with a vacuum pump and the motor stumbled when i opened the valve, so the valve checks out. would you think that its the temp sensor?

thook · 04-29-2008, 12:09 PM

I would.

Alex 400 · 04-29-2008, 12:19 PM

Quote:

Originally Posted by thook

I would.

alright, thanks!

thook · 04-29-2008, 12:28 PM

It's easy to test.

This is the FSM procedure, but you can test it while on the vehicle.
http://personal.utulsa.edu/~nathan-b...00egrgaste.pdf

You can test either in ohms or voltage. In ohms, the resistance should start high and go lower as the temp rises. In voltage, it will be opposite. The volts should start low and rise.

l3fty · 04-30-2008, 08:43 PM

Don't forget to blow/clean out the EGR vacuum modulator filter. I just had the same code right before a 3 hour trip. Blew out the filter and checked the one way valve off the VSV, (I think it may have been stuck) and the CEL hasn't come back. I always start with the easy stuff first.

thook · 04-30-2008, 10:07 PM

Quote:

Originally Posted by l3fty

Don't forget to blow/clean out the EGR vacuum modulator filter. I just had the same code right before a 3 hour trip. Blew out the filter and checked the one way valve off the VSV, (I think it may have been stuck) and the CEL hasn't come back. I always start with the easy stuff first.

Right....good point. I forget about those modulators because I no longer have an EGR! (don't ask....)

Alex 400 · 04-30-2008, 10:49 PM

Quote:

Originally Posted by l3fty

Don't forget to blow/clean out the EGR vacuum modulator filter. I just had the same code right before a 3 hour trip. Blew out the filter and checked the one way valve off the VSV, (I think it may have been stuck) and the CEL hasn't come back. I always start with the easy stuff first.

alright thanks, i will look into that.

Quote:

Originally Posted by thook

Right....good point. I forget about those modulators because I no longer have an EGR! (don't ask....)

well there is no drivability issues, just the annoying light. whenever a CEL comes up, i pull the code just to make sure it is just the egr and not something else.

anotherjeff · 05-01-2008, 11:45 AM

Quote:

Originally Posted by Alex 400

no actually! it turned off for about 7 months then the light would come on everyonce and a while, but it was never on long enough for me to pull the code, i had a little time so i just ran out and pulled the code because the light was on...

uhhh....... Do you realize that codes are stored? In fact, stored until cleared?

anotherjeff · 05-01-2008, 12:00 PM

Quote:

Originally Posted by Alex 400

no actually! it turned off for about 7 months then the light would come on everyonce and a while, but it was never on long enough for me to pull the code, i had a little time so i just ran out and pulled the code because the light was on...

uhhh....... Do you realize that codes are stored? In fact, stored until cleared?

toyota_mdt_tech · 05-01-2008, 08:14 PM

EGR isnt working. Is there a sensor screwed into the EGR valve? IF so, this isnt seeing heat. Usually, its the vacumm hoses in the wrong place or knocked off. Did someone poke around in there?

yotaman8819 · 05-01-2008, 08:43 PM

i have had a code 71 for 3 years and it wont go away

Alex 400 · 05-01-2008, 09:13 PM

Quote:

Originally Posted by toyota_mdt_tech

EGR isnt working. Is there a sensor screwed into the EGR valve? IF so, this isnt seeing heat. Usually, its the vacumm hoses in the wrong place or knocked off. Did someone poke around in there?

yes there is a sensor screwed into the side. I did "poke around" in there to replace my fuel pulsation dampner, in which i had to remove everything. I marked a labled all vacuum hoses to make sure i put them back on in the right places. and i also checked to make sure all of the hoses were in the right place as well. but this had come up even before then, so i don't know...

Alex 400 · 05-01-2008, 09:17 PM

Quote:

Originally Posted by anotherjeff

uhhh....... Do you realize that codes are stored? In fact, stored until cleared?

yes i do know that and i have cleared the code a few times, but sometimes it comes on and stays on for a week or so and then goes off or sometimes it will come on on the freeway and then 20 miles later, sometimes sooner and sometimes just getting off the freeway. drivibility does no change at all whether it's on or off.

4Crawler · 05-01-2008, 09:19 PM

The Factory Service Manual has the EGR testing procedures in it. See if the EGR is opening by manually applying vacuum at idle, should make engine run rough or even kill the engine. The EGR may also be caked with carbon inside, coating the temp sender so that it does not get hot enough to satisfy the ECU.

A buddy of mine had that same problem and ended up getting a new EGR valve and swapping out the old one ('94 pickup). Since it needed to get smogged (in CA), he could not have the CEL coming on at random.

04-29-2008, 11:16 AM	#1 (permalink)
Alex 400 Registered User Join Date: May 2007 Location: Shoreline, Wa Posts: 280	EGR code 71 so my Check engine light kicked on and when i pulled the code, it was code 71. it also said that it was a california car code. but my truck was bought here in washington, as far as i know. for those that have had this code, what was turned up being wrong? thanks guys! __________________ 1994 toyota 4Runner SR5 Limited 4wd, 3.0 V-6 3vze, 5-speed, 31/10.50-15 toyo A/T, All Pro 1.5" coil springs, bilstein front shocks, doetsch tech mv12's rears, , MC heavy duty clutch feasable wish list: 32-11.50R ssr 4.88's ARB air locker Probably-not-going-to-happen wish list: JD fab 4wd long travel kit. other ride:2001 Honda XR400R

04-30-2008, 08:43 PM	#11 (permalink)
l3fty Registered User Join Date: Aug 2007 Location: YL Ca. Posts: 12	Don't forget to blow/clean out the EGR vacuum modulator filter. I just had the same code right before a 3 hour trip. Blew out the filter and checked the one way valve off the VSV, (I think it may have been stuck) and the CEL hasn't come back. I always start with the easy stuff first. __________________ '93 4Runner 3vze A/T 2wd 175k Yeah it's 2wd but it's good for hauling my tools around.

05-01-2008, 08:14 PM	#16 (permalink)
toyota_mdt_tech Registered User Join Date: Aug 2002 Location: WA Posts: 529	EGR isnt working. Is there a sensor screwed into the EGR valve? IF so, this isnt seeing heat. Usually, its the vacumm hoses in the wrong place or knocked off. Did someone poke around in there? __________________ Toyota Master Diagnostic Technician "MDT" 1998 Toyota Tacoma TRD V6 4WD 5 SPD 2003 Toyota Highlander 4WD 2007 KTM 85SX 17/14 2006 KTM 300XC-W 2005 KTM 65SX 2004 Yamaha WR450F 2004 Kawasaki KLX 110 2003 Honda XR50 2002 Yamaha TTR 125L 2002 Kawasaki KLR650 2002 Suzuki Eiger 400 4WD 2004 Cargomate<--link GeePaw® Racing<--link

05-01-2008, 09:19 PM	#20 (permalink)
4Crawler Contributing Member Join Date: Jun 2002 Location: SF Bay Area, CA Posts: 5,764	The Factory Service Manual has the EGR testing procedures in it. See if the EGR is opening by manually applying vacuum at idle, should make engine run rough or even kill the engine. The EGR may also be caked with carbon inside, coating the temp sender so that it does not get hot enough to satisfy the ECU. A buddy of mine had that same problem and ended up getting a new EGR valve and swapping out the old one ('94 pickup). Since it needed to get smogged (in CA), he could not have the CEL coming on at random. __________________ 1985 Toyota 4Runner SR-5, 22REC engine, dual t-cases, 4.88 gears, dual ARBs, 33x10.50 BFGs. r.c.brown@ieee.org TruckEditor@tlca.org Project: 4Crawler 4Crawler OffRoad Gettin'Off 4WD Club Last edited by 4Crawler : 05-01-2008 at 09:21 PM.

04-29-2008, 11:34 AM	#3 (permalink)
anotherjeff Registered User Join Date: Oct 2007 Location: near Redding California Posts: 207	Deja Vu!! Alex, you posted the same question one year ago!! http://www.yotatech.com/f116/egr-code-71-a-119293/ Has your CEL been on for the past year?

05-01-2008, 08:43 PM	#17 (permalink)
yotaman8819 Registered User Join Date: Jan 2008 Location: little rock arkansas Posts: 36	i have had a code 71 for 3 years and it wont go away

05-02-2008, 05:20 PM	#21 (permalink)
Alex 400 Registered User Join Date: May 2007 Location: Shoreline