GMC

GMC troubleshooting questions? Ask a mechanic for answers

Ask an Expert,
Get an Answer ASAP!

Have 1997 gmc box truck with 5.7 throwing up code po1870,

Customer Question
Have 1997 gmc box truck...
Have 1997 gmc box truck with 5.7 throwing up code po1870 , po751 . Checked and ohmed out shift solenoid a a and b or 1 and 2 shows 25 so those check out okay is the po1870 code the Tcc connection on the valve body will that fix that problem for code po1870 also throwing code for crankshaft sensor but checked wiring no problem there any ideas
Submitted: 2 years ago.Category: GMC
Show More
Show Less
Ask Your Own GMC Question
Answered in 10 hours by:
1/19/2016
GMC Mechanic: Pete, GMC Mechanic replied 2 years ago
Pete
Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 33,398
Experience: GM training and dealer tech for 14+ years. Diagnostics
Verified

My name is ***** ***** I am a professional here at Just Answer. I noticed that your question had not received a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.

The codes P1870 here can indicate an internal mechanical fault in the transmission itself with the valve body or another internal mechanical component and is most likely tied into the P0751 code as well.If the valve body has not been tested at all this needs done to see if it needs replaced or if there is another internal mechanical fault in the transmission needing replaced to correct this fault here.

If you have a cam/crank correlation fault code set this may be an issue with a worn gear on the distributor shaft needing replaced as I have seen before.If you can post this code here this will help.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Ask Your Own GMC Question
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a gmc mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Pete Your Own Question
Pete
Pete
Pete, GMC Mechanic
Category: GMC
Satisfied Customers: 33,398
33,398 Satisfied Customers
Experience: GM training and dealer tech for 14+ years. Diagnostics

Pete 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

1,796 satisfied customers

GM Grand Master Technician 2007. 14 year experience.

Gary

Gary

ASE Certified Technician

1,588 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

626 satisfied customers

16 years of experience

Ron Z.

Ron Z.

- GMC Tech -

279 satisfied customers

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

JFN1

JFN1

ASE Certified Technician

270 satisfied customers

GM Master Technician

George H.

George H.

ASE MasterTechnician

228 satisfied customers

15+ Years ASE Master Technician with Level 1 Certification

< Previous | Next >

Related GMC Questions
I have a persistent P0740 light on my 1998 GMC Suburban
I have a persistent P0740 light on my 1998 GMC Suburban C1500 with the 4L60E transmission. I replaced the TCC selenoid and while I had the transmission open, I checked the connector with a DVOM and go… read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
626 satisfied customers
2002 chevy express van 5.7 liter code P0758 2-3 shift
2002 chevy express van 5.7 liter code P0758 2-3 shift solenoid "B" Circuit fault any ideas will be great if you seen the problem and if it is the solenoid easy to get to. Thank you very much 350k on v… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
Have 1997 gmc box truck with 5.7 motor throwing codes po1870
have 1997 gmc box truck with 5.7 motor throwing codes po1870 ,po 751,po102. the po1870 is this a valve body problem or can it be the ignition switch causing this code, read uo on po751 said to check s… read more
supermechanic
supermechanic
Service consultant
Vocational, Technical or Trade Scho
10 satisfied customers
I am getting P0740, P0785 And P0001 after initially changing
I am getting P0740, P0785 And P0001 after initially changing out the inocente sensors due to getting coses for both of them. I also changed out both shift solenoids due to the transmission not shiftin… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
03 gmc sierra 1500 5.3l code p0740, 0753, 0758,0785, & p1860.all
03 gmc sierra 1500 5.3l code p0740, 0753, 0758,0785, & p1860. all tranny codes. Replaced ignition switch. Tested shift solenoids and tcc with were good too. Please point me in right direction… read more
Gm Tech (Cam)
Gm Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
1,796 satisfied customers
GMC K2500 Sierra 4x4: Got a P0894 code on a 2004 GMC 2500 6.0L
Got a P0894 code on a 2004 GMC 2500 6.0L Crew Cab 4 x 4. Harsh shifts from 1 to 2 and 2 to 4 once trans temp gets over about 110 degrees F on the gage. Issue started after having to "rock" the vehicle… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Seirra: 1998 GMC 1500 SLT 4X4 with 4L60E automatic transmission.
1998 GMC 1500 SLT 4X4 with 4L60E automatic transmission. Torque converter locking and unlocking. It does un lock when brake applied but starts unlocking and locking as soon as brake released. All sole… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Yukon Denali: 01 gmc yukon 6.0L 4x4 truck wont come
'01 gmc yukon 6.0L 4x4 truck won't come out first gear not even manual shifting scanner shows no codes and pcm is commanding shifts 1-2 2-3 and 3-4 I removed valve body and cleaned up checked all valv… read more
Pete
Pete
GMC Mechanic
General auto certifications
33,398 satisfied customers
Gmc Jimmy: 2000 gmc jimmy code p0740.trans shifts into all
2000 gmc jimmy code p0740.trans shifts into all gears.the tow engage button has no effect (will not engage).no power found at tow button.possible selenoid or do I go deeper?… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC 1500 Series: I have a 2005 GMC Sierra 1500. I have an engine
I have a 2005 GMC Sierra 1500. I have an engine code P 2761. This is the second time in six months this cold has come back. The first time I change the ignition switch. Where else should I look to try… read more
roy
roy
Associate Degree
3 satisfied customers
GM sonoma: 2000 gmc Sonoma 4.3l 2wd in limp mode, gear indicator
2000 gmc Sonoma 4.3l 2wd in limp mode, gear indicator locked In 3rd gear. p0740, p0758, p01860. shift seliniods where throwing codes, replaced ignition switch and dropped the pan tested shift selinoid… read more
Chris (aka-Moose)
Chris (aka-Moose)
GMC Technician
Vocational, Technical or Trade School
626 satisfied customers
GMC Envoy: I have a 2003 GMC Envoy with 180,000 miles. The
I have a 2003 GMC Envoy with 180,000 miles. The transmission was recently replaced for $3,000, with a three year warranty. Shortly after replacement, the new transmission failed, and was replaced. Now… read more
Eric
Eric
Retired
N/A
14,436 satisfied customers
GMC C3500 HD: 2000 GMC 3500 6.5 diesel no upshift into overdrive
2000 GMC 3500 6.5 diesel no upshift into overdrive after automatic downshift. If you shift the transmission manually into third then back into 4th it will go into 4th. If you turn off the engine and s… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Syclone: I have a 1991 GMC Syclone with a EGR system that
I have a 1991 GMC Syclone with a EGR system that does not work. I have all the OEM GMC service manuals and supplements. I have found the EGR control solenoid to be bad and have replaced it with a OEM … read more
Wolfgang
Wolfgang
11 satisfied customers
GMC: i have a 98 Gmc 1500. it runs fine in all the gears, but
i have a 98 Gmc 1500. it runs fine in all the gears, but when it is cold out putting it in reverse will stall the truck… read more
Gary
Gary
ASE Certified Technician
Vocational, Technical or Trade Scho
1,588 satisfied customers
GMC Yukon XL Denali: I own a GMC Yukon XL Denali package. The
I own a GMC Yukon XL Denali package. The other day the check engine light came on. I took it to the dealership and they scaned the code. It was P2761 Torque converter solenoid open fault. The Tech at … read more
Pete
Pete
GMC Mechanic
General auto certifications
33,398 satisfied customers
GMC 1500 Series: I have a 2000 GMC 1500 with 5.3 v8 I just
I have a 2000 GMC 1500 with 5.3 v8 I just replaced the rear main seal and now the transmission is real sluggish and my obd2 is showing error code 0785 shift timing sol… read more
Dave Nova
Dave Nova
GMC Technician
Associate Degree
929 satisfied customers
GM 1997: 1997 gmc sonoma 4.3 AT engine code X. trans fuse
1997 gmc sonoma 4.3 AT engine code X. trans fuse kept blowing in cab. trans in limp in mode. codes740 tcc solinoid circuit, p0753 1-2 shift soleniod a circuit p0758 2-3 shift soleniod b circuit po785 … read more
JHoop
JHoop
Owner,Technician
High School or GED
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