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 2 of 2
  1. #1

    Default 1987 TBI 350, GMC V1500 service engine soon light

    Hey Nodak here. My 87 suburban V1500 350 auto has been flashing the sevice engine soon light lately. as soon as I shut off the engine and restart, the light goes out. Light comes on, usually after the engine is warmed up, cruising down the highway and tip in the throttle a little more than very slightly. Local "car guy" with code reader gave me a code of 43 ESP. The truck seems to run fine, and if you have to ask about fuel milage, you probably wouldn't know anyway. Any direction or information would be greatly appreciated. Thanks in advance.

  2. #2
    Jr. Mechanic
    Join Date
    Sep 2007
    Los Angeles, CA


    Hi Nodak, code 43 seems to be the knock sensor circuit. That would be the part I would check first. It should come on at wide open throttle when engine temp is above 190 deg. Usually, if the Check Engine light comes on during freeway cruise, it would be an EGR valve which should be a code 34.
    Hope this helps.
    '88 Jimmy 4X4
    5.3l L59/ 4L60E Tuned by Tad
    4" Lift 33" BFG. Custom Brush Guard, KCs, outside spare, Oil pan guard etc.

Similar Threads

  1. 1987 GMC V1500 Suburban front end questions
    By dec7777 in forum General Chevy & GM Tech Questions
    Replies: 4
    Last: 06-22-2012, 02:26 PM
  2. service engine soon light
    By big bopper in forum General Chevy & GM Tech Questions
    Replies: 8
    Last: 05-27-2010, 07:05 AM
  3. Service Engine Light?
    By sc99z71 in forum GM Powertrain
    Replies: 10
    Last: 02-08-2010, 03:10 PM
  4. 1987 V1500 Suburban
    By grateful1 in forum Member Introductions
    Replies: 4
    Last: 01-13-2009, 05:06 PM
  5. Service Engine Light
    By pennyhm in forum Chevy Trailblazer Forum (GMC Envoy)
    Replies: 4
    Last: 03-10-2007, 12:39 PM

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