Jump to content

4x4 Issue


Recommended Posts

Posted

I am having a 4x4 problem. I have done quite a bit of testing and here is what I am up against.

 

Press 4H on dash

Transfer case motor engages

4H light flashes (front axle/diff does not engage)

 

Turn truck off/on

 

Front axle/diff engages - 4x4 engaged (confirmed by having truck up on blocks and verifying wheels don't spin independent any more, also by reversing/turning on dry pavement)

 

4H still flashing

 

I have tried replacing the TCCM but was not the issue.

 

Now suspect that whatever indicates to the system that the transfer case motor has reached position is not sending signal back to TCCM to have it move/actuate front axle. And that somehow turning truck off/on by default has the front actuate.

 

Anyone with information on how the transfer case senses position? Or any details on this issue?

 

Thank you in advance, Mike

Posted

If it's anything like mine, the sensor is a part of the encoder motor. Mine is mounted on the outside but yours could be internal to the motor. Not to insult, but have you checked all the fuses?

Posted

Yes we checked fuses. There is not a separate fuse for the sensor and the motor. Motor is working/moving the transfer case. Just no feedback from what we can diagnose. Probably going to swap out the motor next.

Posted

Most likely the sensor on the motor.

 

But it would be better to scan the TCCM, and diagnose rather than wasting $100's on parts you don't need.

Posted

Thanks guys. We did scan it. Although my friends scan tool does not show the feedback/position indicator of the transfer case or axle actuator . However there were no error codes in the TCCM and we could command each of them to move into the position we requested. Likely will replace the transfer case motor next.

 

EDIT - Found out there are 2 position switches on the transfer case and service tech said these are frequent causes

 

http://www.wholesalegmpartsonline.com/products/SWITCH-Transfer-Case-Shift-Control/3207156/97358605.html

  • 3 months later...
Posted

Re:front axel not engaging

 

After the dealer telling me I'm the only one with the problems, and spending many thousand dollars, I took front left axil apart and found the shaft attached to the shift fork broken in half. New shift fork,- end of problems.

Alan

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    250.6k
    Total Topics
    2.7m
    Total Posts
  • Member Statistics

    343,007
    Total Members
    8,960
    Most Online
    Brendan C
    Newest Member
    Brendan C
    Joined
  • Who's Online   2 Members, 0 Anonymous, 1,006 Guests (See full list)

  • Latest Articles

  • Posts

    • You're better read than that Atlas. 😏   British science fiction writer Arthur C. Clarke formulated three adages that are known as Clarke's three laws, of which the third law – that "any sufficiently advanced technology is indistinguishable from magic" – is the best known and most widely cited.   Stribeck and the pivotable Hersey Number isn't voodoo nor snake oil. That part is physics. It's what marketing and bean counters do with it that is snake oil and voodoo.    Stribeck is the relationship between Hersey and the Coefficient of Friction. Within the Hersey Equation if viscosity and viscosity is 'Dependent' on.......heat.......and.......viscosity index or the temperature to viscosity slope.    Specifically Hersey is the viscosity AT THE TEMPERATURE IN THAT LOCATION FOR THAT SLOPE.   Hydrodynamic lubrication exist when the film thickness in the location is 3X the Ra roughness of the surface. This is irrespective of the hardness of the substrate. To obtain that thickness X viscosity is required for Y velocity at Z load. That's a lot of moving parts. It is also impossible to maintain in an ICE but nearly possible with a turbine under constant load.    What does that mean? Error heavy and operate light. Wear is inevitable but the rate of wear and the milage obtainable are a function of prevailing conditions and HABITS. The only penalty is viscous drag and at fractions so low as to be well worth the effort. Double the life, half the manufacturing carbon foot print. Greed is the only impediment.    The materials generated by SwRI are the RESULT not an estimation or a hypothesis.    Don't delude yourself sir, EV's have as many pitfalls as ICE's. We just don't know what they are yet and it will take longer to sort as MARKETING and GREEDY CEO's have had more time to polish the turd they are selling. 
    • You can always count on greed to prey on ignorance and stupidity.    Friend bought a 2019 Ford Flex and asked me about using Valvoline R&P 5W30 in it. Told him give the miles on it and the fact it wasn't yet using oil that it was a good plan. He uses a Valvoline quick change shop for his oil service.   First they tell him that isn't the oil the OEM recommends. He told them he didn't care what the OEM thought. Then they floated the, "But it will void your warranty"    His reply was it's a 2019, there is no warranty and informed them their knowledge of the law was lacking.    Then they tell him 'But it will ruin your motor"!.    Mine to ruin he says. Finally they give in and charge him 150% the semi-syn price    Point it the brainwash is so embedded that even the service industry is drunk on their swill. The public is right behind them. Echoing the same lies on every forum and media platform. If the end goal is indeed EV then I'd say that ship is about built. 
    • Diesel hit $6.00 here today at the truck stop.   Payed $2.79 for E85 today too.
    • Thanks for posting, I'm sure it will help someone
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...