Intermittent DIC message "BATTERY NOT CHARGING"

Discussion in 'GM Electrical Tech' started by lawman1947, Jun 3, 2012.

  1. lawman1947

    lawman1947 New Member

    When I crank up my 2003 Chev Suburban Z71 (or while driving) the “BATTERY NOT CHARGING” message shows up on the DIC, and once in a while the “SERVICE BRAKE BOOSTER" message will follow. This is random, and usually starts cycling off and on for 20 or 30 minutes, then it might quit for the rest of the drive. After stopping at a destination, it will then restart after I crank up again, and the same thing happens all over again.

    Odd that it is intermittent if the alternator is bad. Could it possibly be Powertrain Control Module going bad? Any ideas? Would the alternator show "bad" if the Powertrain Control Module was failing?

    And if it is the Powertrain Control Module, is it a difficult task to replace it?

    Sure do appreciate an opinion on this...I'm just not able to afford to start randomly replacing parts that don't need replacing, and would really like to know how to get a handle on the problem. Thanks all.
    Last edited: Jun 3, 2012
  2. mfleetwood

    mfleetwood Epic Member 5+ Years ROTM Winner 5000 Posts

    I can't answer as to why it would be intermittent, but you can get your alternator tested for free at most major automotive parts stores. Additionally, they should be able to scan your vehicle for trouble codes, which will also be helpful in diagnosing your problem(s).
  3. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    When it reports that the battery is not charging, what is the voltage indicated by the voltage gauge? Is it somewhere around 12 volts, or somewhere around 14 volts? 14 volts would indicate the alternator is charging, but the computer isn't recognizing it for some reason. 12 volts indicates that the alternator is actually not charging. Do you have a digital multimeter? If so, check the voltage at the battery.

    After verifying whether the computer is telling the truth or not, we need to figure out why it's thinking it's not. The most likely reason is broken, chafed, or loose connections around the alternator. There should be 2 or 3 wires going to the alternator in 1 connector. Those wires turn the alternator on and power indicator lights and such. Double-check to make sure the connection's good and tight and the wires aren't broken or grounded out to anything.
  4. lawman1947

    lawman1947 New Member

    Thanks...I noted that the voltmeter showed around 12 volts, so I assumed it was a bad alternator. But when checking connections under the hood, I noted two loose connections. AFter tightening them up, started the Suburban and it showed 14+volts, and no more messages on the DIC. Sure do appreciate the help!

  5. Crawdaddy

    Crawdaddy All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    I'm glad you were able to resolve your issues. Do you know what that 2 loose connections were for? Were they thick heavy-gauge wires or thin ones?
  6. NorCalChevy

    NorCalChevy New Member

    Hey guys I'm having the exact same problem with my truck 04z71 5.3 but no loose wires new battery new alternator, it's been periodical but now my truck will serge and loose power when my battery get low, it's not charging and I don't know why, very frustrating.. Any thoughts??
  7. new user

    new user New Member

  8. new user

    new user New Member

    Nor-Cal did you ever find out what it was causing your problem? Having similar issues with my truck.
  9. new user

    new user New Member

    Checked battery, alternator, wiring no luck. Shows "battery not charging" and occasionally "service brake booster" also security light stays on all the time, has been that way for 2 years. Also when I turn on the factory alarm the bright light indicator lights up? Any thoughts anyone?
  10. xPosTech

    xPosTech Epic Member 5+ Years 1000 Posts

    Give the guys here some relevant info about your truck. Year, model, engine, trim level (or size of alternator if you know) and any other info that might help us suggest possible remedies.


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