GMC

GMC Troubleshooting Questions? Ask a Mechanic for Answers

Ask an Expert,
Get an Answer ASAP!

GMC

I have a 2001 GMC 2500HD 8.1 with an Allison transmission.

Customer Question
It has an intermittent problem...
I have a 2001 GMC 2500HD 8.1 with an Allison transmission. It has an intermittent problem during upshifting (hard). I have replaced the NSBU and the ignition switch. Fluid level is OK. I have changed the filters and there is no evidence of excessive metal in the pan. Trouble code is P0700 (general transmission)
Submitted: 2 years ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Answered in 16 minutes by:
10/22/2015
GMC Mechanic: Gm Tech (Cam), GMC Mechanic replied 2 years ago
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29,591
Experience: GM Grand Master Technician 2007. 14 year experience.
Verified

Hi there, I am Cam. Can you tell me what code is set in the transmission module itself? P0700 will be reported in the engine on behalf of the transmission module .

Ask Your Own GMC Question
Customer reply replied 2 years ago
I cannot read the transmission module code
GMC Mechanic: Gm Tech (Cam), GMC Mechanic replied 2 years ago

OK, we will need to. However in the absence of the code, we can work on why its shifting hard a bit. Hard shifts are the transmissions response to a slipping condition. It increases pressures to compensate. Anything could be slipping, the Torque Converter Clutch (TCC) , any clutch and it may only be that one lip seal, one sticking valve or something like that is happening and causing it. You replaced the filter, was the magnet still on the external spin on filter?

Ask Your Own GMC Question
GMC Mechanic: Gm Tech (Cam), GMC Mechanic replied 2 years ago

Ok, do you still have the internal filter? Did you open it up and look for signs or a rubber lip seal, anything more than a small particle?

Ask Your Own GMC Question
Customer reply replied 2 years ago
Replaced it. Nothing unusual
GMC Mechanic: Gm Tech (Cam), GMC Mechanic replied 2 years ago

The signs can be subtle. But if nothing then it's something in the valve body, a binding valve then. Take off the valve body and clean it out. Make sure every one moves with no binding. If any do, you may need to replace the valve body.

Ask Your Own GMC Question
Customer reply replied 2 years ago
Rechecked codes. I have an p1875 4wd low switch
GMC Mechanic: Gm Tech (Cam), GMC Mechanic replied 2 years ago

that should not cause a hard shifting. That is just for the 4wd system.

Ask Your Own GMC Question
Ask Gm Tech (Cam) Your Own Question
Gm Tech (Cam)
Gm Tech (Cam)
Gm Tech (Cam), GMC Mechanic
Category: GMC
Satisfied Customers: 29,591
29,591 Satisfied Customers
Experience: GM Grand Master Technician 2007. 14 year experience.

Gm Tech (Cam) is online now

A new question is answered every 9 seconds

How JustAnswer works:

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

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:

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!!!!

AlexLos 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.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, 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.

EstherWoodstock, 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.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Gm Tech (Cam)

Gm Tech (Cam)

GMC Mechanic

29,591 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

1,542 satisfied customers

GCM master tech over 25 years

Dave Nova

Dave Nova

GMC Technician

929 satisfied customers

ASE Master Certification. GM World Class Certification

Chris (aka-Moose)

Chris (aka-Moose)

GMC Technician

563 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

255 satisfied customers

18+yrs experience. State Inspector & GMC Diagnostics/Repair

George H.

George H.

ASE MasterTechnician

225 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

Don - Mo Lurch

Don - Mo Lurch

ASE Certified Technician

216 satisfied customers

GM, GMC, Chevrolet Cert., Heavy Line Mech, Race Shop Owner, Mobile Electronics

< Previous | Next >

Related GMC Questions
I have a 2007 GMC acadia the check engine light came on i
I have a 2007 GMC acadia the check engine light came on i scanned it and it gave me the codes p0016 p0017 i changed the crank shaft sensor 1 were is the second one located i cant find it… read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
I have a 2010 gmc with the 5.3l engine, first the traction
I have a 2010 gmc with the 5.3l engine, first the traction control light came on shortly after that the check eng. light and about 10 min. later it started running ruff. any ideas why/ … read more
Michael Solis
Michael Solis
237 satisfied customers
My check engine light flashing car losing speed. It stayed
it stayed on at first replaced water pump an heater hoses. … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
2010 gmc Arcadia engine codes p2090 p0008 p0301 p2090 p0010
2010 gmc Arcadia engine codes p2090 p0008 p0301 p2090 p0010 p2088 p2094 p0443 p0445 they also said there might be a wiring that is shorting out . What is the issue? … read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,542 satisfied customers
Truck will not remote start and check engine light on.
Truck will not remote start and check engine light on. Advance Diagoned: Getting code P0674 GP cyl 4 issue, U0101 TCCM no comm, and code C0550 … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Engine turns over but wont start. Trouble codes as follows
ok trouble codes as follows PO 301, PO 69E , PO 25A , PO 606...WHERE DO I START? … read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
3,996 satisfied customers
My stepvan utilimaster gas engine Gmc Workhorse is cranking
My stepvan utilimaster gas engine Gmc Workhorse is cranking but not starting. Seems like the ECM isn't getting power. … read more
roy
roy
Associate Degree
3 satisfied customers
I'm having engine surging problems too. ~160k, Automatic.
I've cleaned and reassembled the Mass Air flow sensor, made sure there were not leaks in the pipe … read more
ricardo hohl
ricardo hohl
automotive instructor
Associate Degree
1,818 satisfied customers
With the engine running an turn the headlight switch on the
with the engine running an turn the headlight switch on the engine goes into reduced power mode. If you pull the dimmer the engine dies. … read more
roy
roy
Associate Degree
3 satisfied customers
Creplacet the engine and the instrument cluster does not
creplacet the engine and the instrument cluster does not operate at all now … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
2012 GMC Arcadia engine died will restart takes a time for
2012 GMC Arcadia engine died will restart takes a long time for it to start had code P069E fuel pump module were is this located and is there any specific diagnostics to troubleshoot this issue… read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
3,996 satisfied customers
Traction control light on reduced engine power, No i was
No i was just driving home and power reduced and engine and traction control light came on just happened ten minutes ago no stores open … read more
eauto
eauto
self employed
High School or GED
74 satisfied customers
On the 2012 gmc sierra 1500 the engine harness ends with the
on the 2012 gmc sierra 1500 the engine harness ends with the ecm/pcm, fuse block, throttle control module transmission module what are other two connection ends for… read more
Marvin the Mechanic
Marvin the Mechanic
82 satisfied customers
Engine suddenly stopped when driving and will not even turn
Engine suddenly stopped when driving and will not even turn over … read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
2,066 satisfied customers
Check engine light is on, onstar tells me it is an air
check engine light is on, onstar tells me it is an air filter, yet engine is now sluggish and wont stay on … read more
baddad1
baddad1
technician
High School or GED
5 satisfied customers
Aveo 2009: replaced engine. Engine starts but shuts off with
Aveo 2009: replaced engine. Engine starts but shuts off with in 2 or 3 seconds. Any suggestions … read more
Jerry Newton
Jerry Newton
Vocational, Technical or Trade Scho
2,066 satisfied customers
The reduced engine power symbol is on but with no arrow.
The reduced engine power symbol is on but with no arrow. Have not experienced any change in engine performance since I noticed it today. What does this usually indicate? … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
Just swaped engine and it will not crank, it will not turn
it will not turn over nuthing to do with fuel or spark … read more
AMEDEE
AMEDEE
AUTOMOTIVE TECHNICIAN
Vocational, Technical or Trade Scho
9,105 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x