Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Code 42 then Code 54- kind of long-update

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by fireinthehole, Oct 21, 2003.

    Last week when I was driving my Suburban (89) it kind of bucked and then the SES light came on. I got to my destination and parked it. When I left it started fine and the SES light didn’t come back on until yesterday. Same thing happened, it kind of bucked then SES light came on. I checked to see if a code was stored, and it was 42. So I wrote it down, but had to leave again. I leave and as I am going through an intersection, the Sub dies, SES light comes on. I stop and re-start then go back home. I searched the old posts and read up on it last night. This morning, before I go to work I unhooked the battery to clear the codes, to see if it will happen again. I drive it off and on through the day, no SES. Then I am sitting on a slight incline idling and the SES light comes on again. So when I stop I pull out my trusty paper clip and check for a code, figuring a code 42, but nope now I get 54. I look this up in my service manual and it says fuel pump or fuel pump relay. I haven’t really started to trouble shoot, because of time. But its very strange, I never got these codes before, until I changed out my dist cap, rotor, spark plugs and wires. After reading the posts, I wonder if it’s my ignition module? But why the code 54 now? I guess I just have good luck. /forums/images/graemlins/smirk.gif
    Anybody else in the same boat?

    I had the ignition module tested and it was good. I cleared the codes and replaced the fuel pump relay anyway because they are cheap, and tried to see if it would cure the code 54. After driving a little, the SES light blinked once then a while later came on steady. Checked the code and it was a 54. Too bad I am leaving the Sub for 3 weeks on a business trip, so I wont find out anymore until I get back.
     
  1. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    Re: Code 42 then Code 54- kind of long

    You can read the codes online ON MY SITE... but enuf plugging my site!

    Code 42 - Have you played with your timing lately? Unplugged that barrel plug with the brown wire? That will set code 42. Otherwise... can't hurt to pull the module and have it tested. Autozone will do that for free.

    Code 52 - "Check that CALPAK is in place, fully inserted, and no bent pins" The CALPAK is the "other" chip under the cover on the ECM, the one that DOESN'T get programmed. It contains the "limp mode" info that will get you home incase the system fails.

    Here are a few reasons why it might throw code 52:

    1) Incorrectly installed CALPACK module
    2) Incorrect CALPACK module for this vehicle
    3) Defective or incorrectly inserted PROM
    4) Defective ECM
    5) Missing, as in swapping computers and swapping the eprom but forgetting to swap calpak also!

    My money is on the ECM, or a ground problem. Run a ground wire from the ECM case to the engine BLOCK itself and see if that doesn't help the problem.

    Hope that helps! Good Luck! /forums/images/graemlins/thumb.gif

    -Dan
     
  2. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

    Joined:
    Feb 23, 2001
    Posts:
    3,369
    Likes Received:
    0
    Location:
    Chicago, IL
    Re: Code 42 then Code 54- kind of long

    I must still be sleeping... CODE 54 /forums/images/graemlins/blush.gif is "Fuel pump voltage was not present at fuel pump sense line for 2 seconds after the ECM has sent the fuel pump on command.(Low Voltage)"

    For this... I might check the ground at the tank, and then check the relay. /forums/images/graemlins/tongue.gif Much easier code than 52! You should be happy! /forums/images/graemlins/rotfl.gif

    -Dan
     
  3. Thunder

    Thunder 3/4 ton status

    Joined:
    Jul 20, 2000
    Posts:
    8,946
    Likes Received:
    1
    Location:
    Northeast Nevada
    Re: Code 42 then Code 54- kind of long

    The first things I would check is your Module, And the magnetic pick up coil in the dist. The code 42, stumbling, and CEL are symptons of a bad magnetic Pick Up Coil.
    Problems usually first occur after the engine is warmed up. Usually runs fine when cold.
    To check it:
    With engine warm Pull the cap and un plug the green and white wires inside the dist and measure risistance thru the mag pick up coil should be 500 to 1500 ohms. if out of specs replace it (you have to pull the dist and take off the gear).

    The mag pickup coil and the Dist Module tells the ECM where your timing is at. If the ECM does not see a signal fron the pick up coil/module it assumes there is no spark and shuts off the fuel to prevent flooding. That what is possibly giving the code 54 also.
    Also as said in above post Check all connections and grounds!
     
  4. Re: Code 42 then Code 54- kind of long

    I havent touched the timing or the computer, just the dist cap, rotor, plugs and wires. I will check the module first like Thunder said. I think its funny that you replace old things with new and it causes problems. I guess my Sub liked the old parts better /forums/images/graemlins/wink.gif.
    Thanks for the tips- Mat
     

Share This Page