Announcement

Collapse
No announcement yet.

Check engine Light flickering - HELP!

Collapse

Unconfigured Ad Widget

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Check engine Light flickering - HELP!

    Yesterday When I started my truck the check engine light was flashing fast (sort of flickering). I plugged in my diagnostic tester and the computer has no codes stored.

    The engine is idling fast (about 1500 RPM) and doesn't slow down when warmed up. It seems to run fine but there is obviously something wrong.

    I checked under the hood for loose wires or vacuum leaks and found nothing.

    Any ideas?

    Thanks in advance,

    lowdown

    1988 Chevy Silverado Stepside - 4/6 drop, Katzkin Leather
    Click on signature for truck pics and specs.
    http://www.cartoons.kooldezine.com

  • #2
    Re: Check engine Light flickering - HELP!

    IAC or TPS sensor?
    2016 Carlisle All Truck Nats info..
    http://www.fullsizechevy.com/forum/o...g-5th-7th.html

    Comment


    • #3
      Re: Check engine Light flickering - HELP!

      If the SES light is flashing fast and dim, that signals a failure of the PROM chip in the ECM or the ECM itself. Check connections at the ECM and make sure the PROM chip is firmly seated, if equipped.
      1991 K1500 - 'Red'
      350 Roller Cam TBI, 5-speed manual

      1995 Chevrolet Caprice 9C1 LT1
      Former Arkansas State Police

      Comment


      • #4
        Re: Check engine Light flickering - HELP!

        Originally posted by cletus284
        If the SES light is flashing fast and dim, that signals a failure of the PROM chip in the ECM or the ECM itself. Check connections at the ECM and make sure the PROM chip is firmly seated, if equipped.
        That is what it is doing, I tested it again and this time I got it to thow a code...
        15 - "Coolant temperature sensor or circuit fault - signal voltage high"

        I'm going to go buy a new temp sensor and see if that fixes it.

        Thanks

        1988 Chevy Silverado Stepside - 4/6 drop, Katzkin Leather
        Click on signature for truck pics and specs.
        http://www.cartoons.kooldezine.com

        Comment


        • #5
          Re: Check engine Light flickering - HELP!

          Double check that it is not a code 51 - PROM or MEM-CAL failure. This is consistent with your dim, flickering SES light. I'm getting this info out of my '91 Factory Service Manual.
          1991 K1500 - 'Red'
          350 Roller Cam TBI, 5-speed manual

          1995 Chevrolet Caprice 9C1 LT1
          Former Arkansas State Police

          Comment


          • #6
            Re: Check engine Light flickering - HELP!

            sounds like a short. check out that harness while your putting the temp sensor. let us know how it works out.
            2000 Silverado Z71 5.3
            1994 Blazer 5.7 TBI

            Comment


            • #7
              Re: Check engine Light flickering - HELP!

              For those interested...

              First of all thanks to all for the suggestions, they really helped.

              It wasn't the Temp sensor, it was only 20 bucks so I started there - No Luck.

              I had an old Hyper-tech chip so I put it in and everything id fine now.

              lowdown

              1988 Chevy Silverado Stepside - 4/6 drop, Katzkin Leather
              Click on signature for truck pics and specs.
              http://www.cartoons.kooldezine.com

              Comment

              Working...
              X