+ Reply to Thread
Results 1 to 12 of 12

Thread: NO START PO 300-306 CODE i'm back

  1. #1
    Senior Member

    Status
    Offline
    Join Date
    Aug 2009
    Location
    oak hill, fl.
    Posts
    379
    Blog Entries
    2

    Default NO START PO 300-306 CODE i'm back

    First of all i hate being a parts changer. Been dealing with this issue. Drive for 40 minutes, quits running, no spark code 306 today, towed home to shop,
    i've replaced dist. pick up-crank sensor-cap-rotor-coil-checked and cleaned all grounds-has msd wires-replaced all fuses and Asd. relay all that's left is ECM.
    this truck is perfect, no rust, stored in air cond. shop, 39,000 original miles, 10,000 on 408. Any ideas.?? Replaced parts because had new parts on shelf.
    Thanks.

  2. #2

    Default

    Has the pattern been repeatable, starts up...drive 30-50 mins...quits running...no spark...code 300/306?

  3. #3
    Senior Member

    Status
    Offline
    Join Date
    Aug 2009
    Location
    oak hill, fl.
    Posts
    379
    Blog Entries
    2

    Default

    After first time happened in shop, drove for 120 miles, over 3 days, then died while driving, towed home, sit for 1-2 hrs. then re started after a few tries. Sounds perfect now? Hate to drive and pay for another tow job. Note, i have a snap on scanner and a harbor freight scanner.
    All test ok. When this happened i wiggled all wires, fuses good, plus tap test on ECM. no help.

  4. #4

    Default

    I'm not going to be much help, but it sound like a loose connection (or a recessed pin in a connector) or a broken wire ,just hanging on. I would think an ECU is either good or bad.

  5. #5

    evilrt's Avatar
    Senior Member

    Status
    Offline
    Join Date
    Jul 2019
    Location
    Flint, MI
    Posts
    309

    Default

    Looking over your threads, not sure if you replaced the coil. I would suspect heat and the intermittent nature of it. Maybe check for corrosion on the ECU connectors, Some contact cleaner and reseating.
    Mike Williams
    #001



    98 DA RC GrapeJuice
    99 BLK CC (Buy Back)
    00 BLK RC ProCharged -Hotchkis - on and on (Sold)
    01 AF CC (Leased - Turned in)

  6. #6
    Senior Member

    Status
    Offline
    Join Date
    Aug 2009
    Location
    oak hill, fl.
    Posts
    379
    Blog Entries
    2

    Default

    Coil replaced; all terminals cleaned-inspected. ECU's can be intermittent, but normally respond to tap test [hot or cold] . When no start all wires [wiggle test] no response. I hate guessing but at this point out of ideas. Thanks.

  7. #7

    98Dak408's Avatar
    Supporting Vendor

    Status
    Offline
    Join Date
    Jan 2009
    Location
    Detroit Area, Michigan
    Posts
    2,975

    Default

    Years ago I had problems with several crank sensors going bad back-to-back with my R/T. They can be a pita to remove and install, and for the environment they are in, not very durable. I'm having the same problem with my 3.7 crank sensor. It seems i have to replacement them a couple of times per year. I now keep two spare crank sensors in the glove box, along with a wrench in which to change them out, wherever I may get stranded. The 3.7 usually gives me some short warning that it is about to take a dump. Sometimes the engine feels like it misfires randomly, to completing stalling out. I now know when that begins to happen, I better change it out.
    Last edited by 98Dak408; 06-04-2022 at 05:21 PM.

  8. #8
    pat d's Avatar
    Senior Member

    Status
    Offline
    Join Date
    Aug 2016
    Location
    miami fl
    Posts
    138

    Default

    Have you checked all the ground cables and wires also the relays and fuse panel for loose connections on mine I had some connections that got hot and loose had to unbolt the panel and checked underneath

  9. #9
    Senior Member

    Status
    Offline
    Join Date
    Aug 2009
    Location
    oak hill, fl.
    Posts
    379
    Blog Entries
    2

    Default

    All grounds. + feeds cleaned-tightened. Inc. push on terms.
    Fuel pump replaced with 340 lph. about 10 months ago [TRE] pump-[in tank pump] relay-fuses replaced. but just started doing this.?????????????

  10. #10

    Default

    You check the alternator output? Just about any parts store will do this.
    Sounds like it's giving out.

  11. #11
    Senior Member

    Status
    Offline
    Join Date
    Aug 2009
    Location
    oak hill, fl.
    Posts
    379
    Blog Entries
    2

    Default

    Alternator output 14.3 , batt. perfect . Batt. has 850 amps. on load. .

  12. #12


    GoFastGray's Avatar
    Accumulating parts...

    Status
    Offline
    Join Date
    Jan 2008
    Location
    Ventura, CA
    Posts
    4,525

    Default

    My co-worker had similar issues w/his 5.9 Durango. His ended up being PCM. Would go out after a 30-60min drive constantly.
    12.10@106@Famoso Raceway

+ Reply to Thread

Posting Permissions

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •