How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Dave Nova Your Own Question

Dave Nova
Dave Nova, GMC Technician
Category: GM
Satisfied Customers: 18743
Experience:  ASE Master Certification. GM World Class Certification
Type Your GM Question Here...
Dave Nova is online now
A new question is answered every 9 seconds

2006 GMC: 6.0...trany..higher it shifts hard like it has a shift kit

Customer Question

I have a 2006 GMC 2500hd with a 6.0. When the transmission is cold it shifts great but when the trany gets up to around 110 degrees or higher it shifts hard like it has a shift kit. i had the trany filter changed and it still does it
Submitted: 3 years ago.
Category: GM
Expert:  Dave Nova replied 3 years ago.

Hello and thank you for using JustAnswer. My name is XXXXX XXXXX X will do my best to help you with your GMC problem.

 

Is the check engine light on while driving?

Customer: replied 3 years ago.
yes it is
Expert:  Dave Nova replied 3 years ago.
The hard shifting and the check engine light being on both point to an electrical problem. This will likely be a faulty sensor or a pressure control solenoid within the transmission. The best place to start is to have the computer scanned for trouble codes. You can have the codes scanned for free at Autozone. If you need additional help with diagnosis after you get the codes, please let me know.
Dave Nova, GMC Technician
Category: GM
Satisfied Customers: 18743
Experience: ASE Master Certification. GM World Class Certification
Dave Nova and 11 other GM Specialists are ready to help you
Customer: replied 3 years ago.
i had a romote starter put in lastweek and its done it ever since. the shop checked every connection and said everything was right and it still did it so i unpluged the module and tried it and once again it still did it i just want to make sure it doesnt have to do with that
Expert:  Dave Nova replied 3 years ago.

Even if the remote start is the source of the problem, the trouble codes will still be in the computer for 40 drive cycles or until the codes are cleared with a scan tool. If you can get the codes scanned and then cleared this may alleviate the problem. Record what number the trouble code is and let me know if you need additional help.

Customer: replied 3 years ago.
hey Dave there was no recent code in the system. there was an old code CO894 component slip. They took the pan off and inspected the tcc soleniod because of a bulletin 08-07-30-008B but the soleniod wasn't cracked. is there anything else i should look for?
Expert:  Dave Nova replied 3 years ago.

I believe the problem is in the torque converter clutch system. When there is slippage, the P0894 code will set.

 

Action Taken When the P0894 DTC Sets

  • For California emission equipped vehicles, the PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. For Federal emission equipped vehicles, the MIL is not illuminated.
  • The PCM commands maximum line pressure. This is what causes the harsh shifts.
  • The PCM inhibits the TCC engagement.
  • The PCM freezes transmission adaptive functions.
  • The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame, California only, and Failure Records, California and Federal.
  • The PCM stores the DTC P0894 in PCM history during the second consecutive trip, California, or the first trip, Federal, in which the Conditions for Setting the DTC are met.

Below is a list of potential problems that can cause the P0894 code.

 

  • A TFP manual valve position switch malfunction can set DTC P0894.
  • A mechanical failure of the shift solenoids or TCC PWM solenoid valve can set DTC P0894.
  • Internal transmission failures can result in a DTC P0894.
  • Sticking or contaminated shift valves may cause intermittent slipping in D4.
  • DTC P0894 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.

JustAnswer in the News:

 
 
 
Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.
 
 
 

What Customers are Saying:

 
 
 
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
< Last | Next >
  • I was having a terrible problem with the wheel bearings on my 98 Chevy Cavalier and I suspect that using this website saved me plenty of time and money. Todd L Rochester NY
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
 
 
 

Meet The Experts:

 
 
 
  • Gary's Avatar

    Gary

    GMC Technician

    Satisfied Customers:

    903
    15 years gm master tech/15 years ASE master tech
< Last | Next >
  • http://ww2.justanswer.com/uploads/ggrote1/2009-06-27_031011_me.jpg Gary's Avatar

    Gary

    GMC Technician

    Satisfied Customers:

    903
    15 years gm master tech/15 years ASE master tech
  • http://ww2.justanswer.com/uploads/CA/caprio23/2011-12-13_155550_20111213105344.64x64.jpg Anthony's Avatar

    Anthony

    ASE Certified Technician

    Satisfied Customers:

    476
    ASE Master Automobile Technician with over 20 years exp.
  • http://ww2.justanswer.com/uploads/Rocket2005/2009-09-13_133703_jack.jpg car tech's Avatar

    car tech

    ASE Certified Technician

    Satisfied Customers:

    448
    25 year master tech and shop owner
  • http://ww2.justanswer.com/uploads/2P/2paulm/2012-4-4_183431_justabswer.64x64.jpg Paul M ASE Master's Avatar

    Paul M ASE Master

    ASE Master Tech

    Satisfied Customers:

    187
    ASE Master Tech 20+ Years
  • http://ww2.justanswer.com/uploads/MU/muddyford/2012-6-13_1204_1.64x64.png Chris (aka- Moose)'s Avatar

    Chris (aka- Moose)

    GMC Technician

    Satisfied Customers:

    89
    16 years of experience
  • http://ww2.justanswer.com/uploads/AM/amedee/2013-10-24_23656_Amedee1.64x64.jpg Amedee's Avatar

    Amedee

    GMC Technician

    Satisfied Customers:

    360
    ASE Master Technician advanced level specialist
  • http://ww2.justanswer.com/uploads/DT/dt69nova/2012-6-15_234154_pic1.64x64.jpg Dave Nova's Avatar

    Dave Nova

    GMC Technician

    Satisfied Customers:

    2262
    ASE Master Certification. GM World Class Certification