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Related Medium and Heavy Trucks Questions
In need of the ecm pinout for a 1997 cat 3116e engine serial
In need of the ecm pinout for a 1997 cat 3116e engine serial #8WL05369 on 1999 gmc vin # ***************** I'm swapping the engine with a 3126 out of another gmc but the harness plug that goes into th… read more
Nich1019
Nich1019
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Vocational, Technical or Trade School
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Shut off engine and won't start in morning, in shop and
Shut off engine and won't start in morning, in shop and warm. No fuel getting as in shutdown switch or something … read more
Wayne
Wayne
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I'm working on a 2001 Kenworth t300, with a cat 3126 and an
I'm working on a 2001 Kenworth t300, with a cat 3126 and an Allison trans. I have a crank no start situation and am unable to communicate with the ecm.… read more
Nich1019
Nich1019
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Vocational, Technical or Trade School
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I am working on a 98 gmc c7500 with 3126 Cat that I could
I am working on a 98 gmc c7500 with 3126 Cat that I could not get started. I checked powers and grounds and I found o had no key switch power to pin 70. I jumped key switch power to that pin. Truck st… read more
Gary A.
Gary A.
Associates in Diesel Technology and Business Management
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1999 freightliner fl60 with cat 3126. Will not start. Wait
1999 freightliner fl60 with cat 3126. Will not start. Wait to start light not coming on and scanner will not communicate with ecm. Unplugged wiring harness going to sensors to rule out a shorted senso… read more
Cat Man
Cat Man
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Vocational, Technical or Trade Scho
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I am working on a 1998 GMC C7500, with CAT 3126, No cruise
I am working on a 1998 GMC C7500, with CAT 3126, No cruise control. Truck will start when it wants to and will run for 30 min. and shutdown, like someone turned the key off. Check engine flashes. I ca… read more
Wayne
Wayne
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Vocational, Technical or Trade Scho
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1999 GMC C8500, Cat 3126, Allison MT 653. I installed a
1999 GMC C8500, Cat 3126, Allison MT 653. I installed a reman Allison. It now gives random check engine lights and derates the engine. No codes stored, but a drive test says loss of vehicle speed sign… read more
Daniel Wilson
Daniel Wilson
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Would like to start diagnosing a problem with my 3126 using
Would like to start diagnosing a problem with my 3126 using cat man … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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2003 f650 3126 cat died wont start check engine light does
2003 f650 3126 cat died wont start check engine light does not come on now communication with cat et, have power and ground to ecm and ignition hot on pin 70, replaced ecm with reman from cat still ca… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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Have a 6500 GMC cat 3217 dies intimately sometimes ruse for
Have a 6500 GMC cat 3217 dies intimately sometimes ruse for weeks before it dies. … read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
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I have a 2003 GMC 7500 with a 3126 cat, truck came in no
Hello, I have a 2003 GMC 7500 with a 3126 cat, truck came in no start no crank, could not communicate with ecm, checked power and grounds found all ok, replace ecm, now I can communicate with ecm and … read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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98 fl70 with cat motor. Doesn't crank below 32 deg. Replaced
98 fl70 with cat motor. Doesn't crank below 32 deg. Replaced starter and solenoid with no change. Is there another electric relay or could it be the ign. Switch?… read more
Daniel Wilson
Daniel Wilson
Auto Mechanics 1&2/diesel mech
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HAVING TROUBLE STARTING OUR CAT ENGINE. TRUCK IS A 98 GMC
HAVING TROUBLE STARTING OUR CAT ENGINE. TRUCK IS A 98 GMC 6500. ENGINE IS A 3126, ALLASON TRANS. ENGINE RAN GREAT A FEW DAYS AGO. NOW IT WONT START. STARTS WITH STARTING FLUID, BUT WONT CONTINUE TO RU… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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Cat man got 98 3126 in a gmc t7500 truck that starts and
hey cat man got 98 3126 in a gmc t7500 truck that starts and runs fine but goes into limp mode and only revs to 1700 unless u shut off and restart, it only has a obd2 connector and doesnt want to comu… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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1999 GMC C7500 3126 Cat. Occasional hard start. "No ECM
1999 GMC C7500 3126 Cat. Occasional hard start. "No ECM detected" when hooking up scanner.… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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2003 GMC c6500 runs fine, no communication on data link. CAT
2003 GMC c6500 runs fine, no communication on data link. CAT 3126, Allison auto, hydraulic abs. I use both nexiq USB link or CAT adapter II with all OEM softwares. My equipment connects to every other… read more
Travis A. Wells
Travis A. Wells
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GMC C6500: I need the accelerator position sensor wiring diagram
I need the accelerator position sensor wiring diagram for a 2001 gmc 6500 w/ a 3126 Cat please.… read more
Cat Man
Cat Man
Cat Engine Expert
Vocational, Technical or Trade Scho
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2000 GMC topkick with a 3126 cat engine. Shut off while running,
2000 GMC topkick with a 3126 cat engine. Shut off while running, will not restart. Checked voltage to ecm. 12 volts to pins 52 an 53 .I have 1200 psi. pressure in high pressure manifold while cranking… read more
Cat Man
Cat Man
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10,344 satisfied customers
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Meet the Experts:

Daniel Wilson

Daniel Wilson

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cumminsdr

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Chris (aka-Moose)

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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.

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