Trucking Jobs New Driver Jobs Flatbed Jobs Tanker Jobs Refrigerated Jobs Auto Hauler Jobs
Results 1 to 8 of 8
  1. #1
    Bobtail Member
    Member Since
    Jun 2010
    Trucker?
    5 Years
    Posts
    14
    Thanks
    0
    Thanked: 5 Times

    disconnected egr with check engine light on

    I was driving today thinking about how to get the cel light to go off. I took an extra pig tail out of my side box put a bulb in it and part of my theory was right I stuck the wires in the unplugged portion of the egr and guess what? the light came on but the cel light stayed on. My theory was the plug didn't know wheather it was turning on the egr motor or the light. so I am thinking it must be a sensor also after the egr cooler so If anyone can build on my way of thinking and get the cel light to go off I'll be watching this post for insight.


  2. The Following User Says Thank You to 07 pete For This Useful Post:


  3. #2
    Bobtail Member
    Member Since
    Jun 2010
    Location
    Hagerstown, MD
    Trucker?
    No Answer
    Posts
    4
    Thanks
    0
    Thanked: 0 Times
    It is either detecting an electrical problem or a mechanical problem. Depending on what the code is, it is looking for something different. If its the unplugged electrical connector, then it has to see something that puts the same resistance as the EGR valve. But if its for a mechanical fault code, (low egr flow, etc) its probably looking for a certain amount of EGR elsewhere in the engine which is looking at the EGR valve when the engine is running. not something you can just block off, plug, etc.

  4. #3
    Trucker Forum STAFF - Gone, But Never Forgotten Gears's Avatar
    Member Since
    Aug 2009
    Trucker?
    8 Years
    Age
    54
    Posts
    4,501
    Thanks
    3,978
    Thanked: 3,167 Times
    My CEL came on too. I left the key in the on position while unplugging the EGR. This morning I plugged it back in and the light went off. I'll try unplugging the EGR after turning the key off after 30 seconds or so to see if that makes a difference. Maybe that red wire next the cable that gets unplugged should be unplugged too?

  5. #4
    Light Load Member NRG's Avatar
    Member Since
    May 2010
    Location
    Edmonton AB
    Trucker?
    12 Years
    Age
    38
    Posts
    166
    Thanks
    11
    Thanked: 41 Times
    It should throw an "active" electrical fault code, not a CEL. Since there is an interrupted sensor connection. I did 10k miles so far with EGR off... (unplugged and tapped the 6 o`clock sensor with the key `on` for 15 sec.) so far so good. Water temps are definitely down and getting 7.5 mpg avarage at 65-70mph with 77k gross climbing west coast.

  6. #5
    Light Load Member belltransit's Avatar
    Member Since
    Jun 2010
    Location
    oak grove, mo
    Trucker?
    21 Years
    Posts
    271
    Thanks
    0
    Thanked: 22 Times
    the best way to turn off the light??? pull the bulb!!!

  7. #6
    Road Train Member ChromeDome's Avatar
    Member Since
    Jun 2007
    Location
    Tampa, FL
    Trucker?
    12 Years
    Age
    44
    Posts
    3,449
    Thanks
    28
    Thanked: 1,893 Times
    The best way would be to find out what electrical resistance the EGR valve is giving when hooked up, and then making a resistor plug to put on the wire. This will fool the system into thinking that the valve is still hooked up.

  8. The Following User Says Thank You to ChromeDome For This Useful Post:


  9. #7
    Light Load Member mrdevildog's Avatar
    Member Since
    Feb 2010
    Location
    Heber Springs, Arkansas
    Trucker?
    No
    Posts
    75
    Thanks
    0
    Thanked: 21 Times
    the light is not going to go off, the ecm sends out voltage to open and close the valve. also it sends out voltage to a position sensor mounted on the side of the egr, it knows what the flow is because of a pressure sensor the is mounted down stream in the egr crossover pipe. to make a long story short the ecm is smart enough to know whats going on with the system, it was designed/programed that way, if you unplug a connector it will know because it does self diagnostics, its a nice theory but the only way to keep the bulb off is to pull the light bulb or run the engine the way it was designed for. even if you make a resistor or something to put in the connector, the ecm is going to know about it and set other fault codes which in turn will turn on the check engine light.

  10. #8
    Road Train Member
    Member Since
    Feb 2010
    Location
    Rock Creek B.C. Canada
    Trucker?
    44 Years
    Posts
    1,526
    Thanks
    56
    Thanked: 569 Times
    Quote Originally Posted by mrdevildog View Post
    the light is not going to go off, the ecm sends out voltage to open and close the valve. also it sends out voltage to a position sensor mounted on the side of the egr, it knows what the flow is because of a pressure sensor the is mounted down stream in the egr crossover pipe. to make a long story short the ecm is smart enough to know whats going on with the system, it was designed/programed that way, if you unplug a connector it will know because it does self diagnostics, its a nice theory but the only way to keep the bulb off is to pull the light bulb or run the engine the way it was designed for. even if you make a resistor or something to put in the connector, the ecm is going to know about it and set other fault codes which in turn will turn on the check engine light.
    Could not have said it better my self.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •