Go Back   Camry Forums - Toyota Camry Enthusiast Forum > Your Ride > Engine & Internal
Sign in using an external account
Register Forgot Password?
Search

Reply
 
 
 
submit to reddit
 
LinkBack Thread Tools Search this Thread
  #1  
Old 06-15-2011, 07:20 PM
Junior Member
 
Join Date: Jun 2011
Posts: 2
Default P0402 code Excessive flow

My 96 Camry XLE V6 has a code P0402. Excessive flow. The dealer wants to replace the EGR, VSV, and something else for $840. FIrst, I don't trust that dealer for several reasons, so I think they want to change it all out to be sure. Should I start with the VSV, and are there more than one? How do I identify the culprit? THe EGR is right on top, so I thought I would just buy one on line. Advice?
This ad is not displayed to registered members.
Register your free account today and become a member on Camryforums!
Reply With Quote
  #2  
Old 06-15-2011, 10:13 PM
Super Moderator
 
Join Date: Jan 2008
Location: PTW
Posts: 7,563
Default

The code is set if the valve is physically lifted more then 0.1 inch when the EGR system is off. The EGR is off (valve closed) when the engine coolant is cold, throttle closed-idling and a few other times.

The EGR valve is moved by a vacuum diaphragm, the vacuum coming from the intake manifold. The VSV controls vacuum On/Off, turning the EGR system on and off. When the VSV is on, the valve can move more open or closed regulating exhaust gas based engine needs (vacuum).

The computer knows the physical position of the valve by means of a position sensor mounted on the EGR valve body.

The valve is either not seating fully when closed most likely due to carbon build up, the VSV is not closing allowing vacuum to get by or the position sensor has failed and is given the computer incorrect info. Could also be wiring issues but you should be able to these.

If you disconnect the vacuum line going to the VSV from the intake manifold the EGR system should be off. If the system is working correctly there should not longer be any EGR gas flow.

If the EGR valve was stuck open too far the exhaust gases would cause the engine to idle poorly or if open far enough not start. How does the car idle? If the same as before the check light came on might be the position sensor.

The AutoZone website may have diagnostic info on the site vehicle repair guides.

The Rockauto website would have the parts listed, often with photos.

There is only one VSV for the EGR system but the may be other VSV's mounted on the engine. Make sure you find the correct one. The one with the hoses running from the intake manifold and the EGR valve.
__________________
Joey P
Super Moderator
Reply With Quote
  #3  
Old 06-16-2011, 09:51 AM
Junior Member
 
Join Date: Jun 2011
Posts: 2
Default

Quote:
Originally Posted by toyomoho View Post
The code is set if the valve is physically lifted more then 0.1 inch when the EGR system is off. The EGR is off (valve closed) when the engine coolant is cold, throttle closed-idling and a few other times.

The EGR valve is moved by a vacuum diaphragm, the vacuum coming from the intake manifold. The VSV controls vacuum On/Off, turning the EGR system on and off. When the VSV is on, the valve can move more open or closed regulating exhaust gas based engine needs (vacuum).

The computer knows the physical position of the valve by means of a position sensor mounted on the EGR valve body.

The valve is either not seating fully when closed most likely due to carbon build up, the VSV is not closing allowing vacuum to get by or the position sensor has failed and is given the computer incorrect info. Could also be wiring issues but you should be able to these.

If you disconnect the vacuum line going to the VSV from the intake manifold the EGR system should be off. If the system is working correctly there should not longer be any EGR gas flow.

If the EGR valve was stuck open too far the exhaust gases would cause the engine to idle poorly or if open far enough not start. How does the car idle? If the same as before the check light came on might be the position sensor.

The AutoZone website may have diagnostic info on the site vehicle repair guides.

The Rockauto website would have the parts listed, often with photos.

There is only one VSV for the EGR system but the may be other VSV's mounted on the engine. Make sure you find the correct one. The one with the hoses running from the intake manifold and the EGR valve.
To Joey P - Man, I really got my money's worth with this one! It all makes sense to me. Since it starts and idles well, I suspect carbon buildup on this 15-year old car that is city driven. I will follow the hoses from the EGR to find that VSV for the first operation and see what happens. Some web posts show this VSV very inaccessible. If so, at least I might now direct a local shop to this solution first. Thanks.
Reply With Quote
Old 06-16-2011, 09:51 AM
 
 
 
submit to reddit
Reply

Tags
1996, 97, camry, code, control, diagram, egr, excessive, flow, idle, p0402, toyota, v6, valve, vsv

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 11:21 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.