Newest Gallery Photos

  1. Chevy Truck Forum

    Welcome To!

    The #1 Chevy Truck Forum Online

    Online since 2004, we're the #1 Chevy Truck & SUV user community. If you have any questions about your Chevy or GMC Truck, SUV or Crossover, or just want to connect with other GM owners and enthusiasts around the world, you've found the best place on the internet to do that.

    Join Today ~ It's Free

    Registering is Free and Easy! Do it today and we'll see you on the forums soon!

PCM B Fuse blowing on '91 sub, 350 TBI -- PLEASE HELP

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by rdnkdrummer, Sep 2, 2011.

  1. rdnkdrummer

    rdnkdrummer Rockstar

    I haven't found many helpful posts about this so I'm asking myself...what in the HELL does the PCM B fuse go to?

    I've read things about fuel pump, fuel pump relay, ecu, ignition switch, etc. No one really seems to have hit the nail on the head yet.

    My dilemma: twice in the last week my truck has randomly died while driving. Culprit: Blown PCM B Fuse. Engine still getting fire...will run for a few secs when gas is poured down TB and started. Which tells me it's fuel-pump related. That's all I know. I know others are still trying to figure this out as well.


    And thanks :)

    PS, how bad would it be for me to just put a 10A circuit breaker in the fuse slot? I've done it before with the idle/gage fuse that was blowing randomly on another truck, with no problems.
  2. rdnkdrummer

    rdnkdrummer Rockstar

    Figured I'd bump/update this one in case anyone is having similar issues...

    PCM B has to do with the fuel pump, and shuts it off if the fuse blows. In my case, there's a small short somewhere in the circuit that trips when I drive over very bumpy or gravel roads. I put a circuit breaker in, hasn't been an issue since, as the problem is never more than 1/2 second.

Share This Page