GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 3 of 3
  1. #1

    Default 95 Chev Suburban "service engine light"

    Hello, I have a 1995 K1500 Suburban with 5.7l engine with throttle body injection with 181,000 miles. It runs great except for the following condition:

    I drive to and from work each day about 25 miles one way. I reach highway speeds and I believe the engine gets thoroughly heat soaked. After about 15 miles, the "Service engine soon" light comes on every day. I believe the computer is OBD1, it has the 12 pin connector. I followed a procedure I found that says to ground pins A and B in the connector and turn the key on to retrieve codes. It did not flash, meaning to me the computer hasn't saved any codes, or this grounding in the connector doesn't work or some other problem with communication with the computer. Would anyone have suggestions?

    One side note about the engine. While the engine is still warming up and has not reached operating temp, the engine has a significant pre ignition knock when you put the engine under load. It reduces as the engine reaches operating temp.

    Any suggestions from anyone would be appreciated. Great website!

  2. #2


    Update, I went to O Reillys to pick up a fuel filter and asked if they had a scan tool. They did and let me borrow it. I ran diagnostics on it and it had a code saved. 32 EGR FAILURE. That is the only code. If I did it correctly. So I went and inspected the vac line to the EGR valve, it looks ok. I reached in to the valve to see if it would move and it does. It doesn't appear to be stuck. I am going to remove it and inspect it and see if I can see anything.

    Any thoughts?

  3. #3
    Legend unplugged's Avatar
    Join Date
    Sep 2006
    High Deserts of SoCal

    Default Simple test

    To test an egr valve, I use a length of vacuum hose and apply suction to see if the egr valve operates and holds vacuum. If it doesn't, hold vacuum replace the valve.
    There is no way to happiness....happiness is the way.:yipi:  _vXMYypuKMJFw671uF2ZPhjez_j-atRmcjM2zQKpQi1JSsB75/burb1.JPG
    High Desert SoCal
    93 K1500 burb (personal) 350 AT 3" Lift 250K+
    02 Honda Civic LX
    Looking for a 1990's Miata for an engine swap

Similar Threads

  1. "Service Brake System" accompanied by SERIOUS truck freakout. PLEASE help us!
    By theclicks in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 5
    Last: 01-08-2011, 12:06 AM
  2. 2003 Suburban "Reduced engine power"
    By medicjack in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 1
    Last: 02-12-2010, 11:10 PM
  3. "Service Engine Soon" light
    By gaboytroupco in forum Member Introductions
    Replies: 11
    Last: 11-30-2009, 07:28 AM
  4. What does "detonation" sound like? Engine "knock"?
    By Big6ft6 in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 32
    Last: 08-04-2009, 01:04 PM
  5. Warning light on Dash.."SERVICE 4WD"
    By Shambion in forum Chevy Trailblazer Forum (GMC Envoy)
    Replies: 1
    Last: 12-24-2005, 02:22 AM

Tags for this Thread

Posting Permissions

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