GM

GM repair problems? Ask a GM repair expert now.

Ask an Expert,
Get an Answer ASAP!

Need experienced 01 6.6l duramax mechanic with electrical…

Customer Question
Need experienced 01 6.6l duramax...
Need experienced 01 6.6l duramax mechanic with electrical skills. Truck was fogging diesel while idling, but ran fine while driving. Replaced all injectors and fuel lines, bled system, no start. I am not getting any injector command on scan tool. Shows good fuel pressure while cranking, but obviously won't start if injectors won't open. New cam and crank position sensors and reluctor ring was solid. Where does the ficm get it's signal to command injector to open?
Submitted: 2 years ago.Category: GM
Show More
Show Less
Ask Your Own GM Question
Answered in 56 minutes by:
3/9/2016
GM Mechanic: Juan Crespo, ASE Certified Technician replied 2 years ago
Juan Crespo
Juan Crespo, ASE Certified Technician
Category: GM
Satisfied Customers: 1,532
Experience: A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
Verified

The FICM gets its signal from the PCM. As you describe it, it sounds like your anti-theft system has been activated and is currently not allowing the engine to start.

The Passlock(tm) system is designed to prevent vehicle theft by disabling the engine unless a mechanical key is used to correctly engage and rotate the Passlock(tm) lock cylinder. System components include ignition switch, Passlock(tm) lock cylinder, Passlock(tm) sensor, Passlock(tm) module and Powertrain Control Module (PCM).

Do you have a second passlock key that you can try? If not, you would need a scan tool capable of communicating with the various modules in the truck to see what's happening.

Ask Your Own GM Question
GM Mechanic: Juan Crespo, ASE Certified Technician replied 2 years ago

Thought you might need this:

30-MINUTE LEARN PROCEDURE
1. Turn ON the ignition, with the engine OFF.
2. Attempt to start the engine, then release the key to ON, vehicle will not start.
3. Observe the SECURITY telltale. After approximately 10 minutes, the telltale will turn OFF.
4. Turn OFF the ignition, and wait 5 seconds.
5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes. The vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK.
6. Start the engine. The vehicle has now learned the Passlock Sensor Data Code and/or password.
IMPORTANT: The vehicle learns the Passlock Sensor Data Code and/or password ***** the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.
7. With a scan tool, clear any DTCs if needed. History DTCs will self clear after 100 ignition cycles.

Ask Your Own GM Question
Customer reply replied 2 years ago
Juan, key on, there is no security light, my research shows no passlock on this truck. Also no "+" on the key to show it has a resistor. Please tell me about the security telltail.
GM Mechanic: Juan Crespo, ASE Certified Technician replied 2 years ago

If, as you say, there's no passlock on that truck, then there's no Security telltale nor, if the truck has the optional Message Center, the word SECURITY will be displayed.

In any case, I can't see where anything you've done would cause the engine not to start. So, the only way to find whether or not there is communication between the PCM and the FICM or if there is something else preventing the signal from getting through is with the help of a Tech-II or equivalent scan tool.

Ask Your Own GM Question
Customer reply replied 2 years ago
I do have a scan tool, that's how I know there is no injector command as stated in original message, I need to know which wires to probe to know if problem is in the ecm or ficm.
GM Mechanic: Juan Crespo, ASE Certified Technician replied 2 years ago

I'm sorry if I didn't explain it better: the computers in your truck communicate with one another through a serial data bus; probing these bus wires with anything but a scope won't show us much - even with a scope, all we'd see is a serial data signal if one was there. We still wouldn't know what that serial data meant.

What we need is a dealer-level scan tool such as the Tech-II that can communicate with all the modules in the truck, read serial data and interpret it for us. It can also tell us if any of those modules is preventing others from getting the signals they need to go to work. I wish the carmakers had made it easier for us to work on these vehicles, but they just want to push us back to their dealers where they can charge us whatever they want

Ask Your Own GM Question
Customer reply replied 2 years ago
Juan, So what your saying is you can't help me right?
GM Mechanic: Juan Crespo, ASE Certified Technician replied 2 years ago

I'm afraid I would have to agree with you, since you don't seem to have access to the tools you would need to use in order to follow my intructions. But wait, another expert on the site might know what to do. I'll opt out so others may try. Please don't reply until another expert responds or the site will cycle the request back to me.

Ask Your Own GM Question
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago
Chris (aka- Moose)
Chris (aka- Moose), GMC Technician
Category: GM
Satisfied Customers: 51,649
Experience: 16 years of experience
Verified

Welcome, I'm Chris (aka Moose). Experts aren't employees / agents of Just Answer. We are independent service providers using the Site to sell their Expert knowledge to Customers. I strive to provide EXCELLENT 5 STAR service, let me know what's needed from me so your pleased.

  1. The previous tech has opted out. Would you like me to help?
Ask Your Own GM Question
Customer reply replied 2 years ago
please
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

So your getting no trouble codes?

Are the cam and crank sensors getting an accurate signal back to the PCM?

Ask Your Own GM Question
Customer reply replied 2 years ago
as to codes, p0340 cam sensor or circuit. Sensor has ok volts(10.6), good ground and frequecy when tested aprox. 4" from sensor. not sure what pin or connector to check at ECM.
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

Using your scan tool and cranking the engine are you getting a CMP and CKP signal that is consistent and just about identical?

Ask Your Own GM Question
Customer reply replied 2 years ago
Using a ds 708. There is only cam reference signal missed(0) and no CKP signal( shown on this scanner) also no rpm reading i.e. (0) during cranking.
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

Your scan tool may not be sophisticated enough. Do you have the ability to try another. We need to confirm the computer is getting these signals to figure out why your getting no injector signal.

Ask Your Own GM Question
Customer reply replied 2 years ago
If you can tell me wich pins to probe at the ecm, I could at least verify a signal to the ecm. This truck has 380000 miles on it and it could be bad wire.
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

CKP:

low reference pin 21 YE/BK

CKP signal pin 12 LB/WH

12 volt reference pin 2 LG

CMP:

CMP signal pin 73 BR/WH

low reference pin 61 PK/BK

12 volt reference pin 39 RD this is the only one in connector 2 at the ECM

Ask Your Own GM Question
Customer reply replied 2 years ago
continuity to ecm checks good(CKP, CMP), still no rpm and p0340 code returns after clearing. I could get another scanner to check cmp and ckp, but if they read 0 as I assume they will, then it looks like ecm is the culprit. FICM will not command injectors if it doesn't see RPM, correct?
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

Your correct if the FICM is not getting a signal, it will not pulse the injectors.

Ask Your Own GM Question
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

Hello again Chris here,

1) When customers come to Just Answer the website and the experts want them to have a great 5 star experience.

2) We also want them to be so pleased that they come back for future needs.

3) I have the feeling you were not pleased with my help and or need me to help more. If so please do reply.

4) I have an option to upload diagrams, repair guides, find a repair facility, or call you if that would help.

Thanks Chris

Ask Your Own GM Question
Customer reply replied 2 years ago
Hi Chris, yes I would appreciate any additional help. Have you ever heard of air in the fuel line causing a po340 code? Also could you please walk me thru the fuel bleed process as you know it? Seems simple, but maybe I'm missing something.
GM Mechanic: Chris (aka- Moose), GMC Technician replied 2 years ago

A fuel issue that may be causing a misfire could cause a incorrect CMP and CKP code to store from the engine speed abruptly changing. There is a priming step, not a bleeding step.

https://dl.dropboxusercontent.com/u/90220402/prime.pdf

Ask Your Own GM Question
Was this answer helpful?
Ask Chris (aka- Moose) Your Own Question
Chris (aka- Moose)
Chris (aka- Moose)
Chris (aka- Moose), GMC Technician
Category: GM
Satisfied Customers: 51,649
51,649 Satisfied Customers
Experience: 16 years of experience

Chris (aka- Moose) 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:

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 LRochester 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!!!!

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

< Previous | Next >

Meet the Experts:

GM Tech (Cam)

GM Tech (Cam)

GMC Mechanic

5,792 satisfied customers

GM Grand Master Technician 2007. 14 years experience.

Gary

Gary

GMC Technician

1,537 satisfied customers

15 years gm master tech/15 years ASE master tech

car tech

car tech

ASE Certified Technician

449 satisfied customers

25 year master tech and shop owner

Chris (aka- Moose)

Chris (aka- Moose)

GMC Technician

51,649 satisfied customers

16 years of experience

Paul M ASE Master

Paul M ASE Master

ASE Master Tech

187 satisfied customers

ASE Master Tech 20+ Years

Anthony

Anthony

GMC Technician

489 satisfied customers

GM Certified

Amedee

Amedee

GMC Technician

455 satisfied customers

ASE certified tech with advanced level specialist. Wisconsin certified emissions state inspector

< Previous | Next >

Related GM Questions
Hummer h2 dont recognize my key start then cut off. New
hummer h2 dont recognize my key start then cut off … read more
GM Tech (Cam)
GM Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
5,792 satisfied customers
2004 Oldsmobile Silhouette brake and reverse lights are not
2004 Oldsmobile Silhouette brake and reverse lights are not working.. … read more
Mechanic01
Mechanic01
2,596 satisfied customers
Hummer h3 alpha '08. Low beam/daytime running lights have no
Hummer h3 alpha '08. Low beam/daytime running lights have no power to the fuses, but high beams work fine … read more
Mechanic01
Mechanic01
2,596 satisfied customers
I need to verify the input signal and output signal of a GMC
Hello, I need to verify the input signal and output signal of a GMC Acadia SLT Bose amplifier, also i need a diagram that show how factory speakers connected. … read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,284 satisfied customers
P0521 code. Previous owner changed the connector. P0521 oil
New connector, New sensor, checked voltage and oil pressure. Changed the filter screen … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
My 1994 Pontiac Trans Sport vacuum line seems not working
My 1994 Pontiac Trans Sport vacuum line seems not working properly. … read more
kalamykid
kalamykid
Pactor automotive
Vocational, Technical or Trade Scho
97 satisfied customers
I have a 2004 hummer H2 that has two problems. One is that
I have a 2004 hummer H2 that has two problems. One is that the key will not come out of the ignition. The other is it keeps going into limp mode . I am getting code P0740B code P0753B code 7058A code … read more
GM Tech (Cam)
GM Tech (Cam)
GMC Mechanic
Vocational, Technical or Trade Scho
5,792 satisfied customers
I have a 2004 GMC Yukon XL Denail. Every once in a while
I have a 2004 GMC Yukon XL Denail. Every once in a while when driving, the dashboard would light up like a Christmas tree for a few seconds, then everything was normal. Today, I start the truck and no… read more
Chad Farhat
Chad Farhat
Owner
Associate Degree
5,165 satisfied customers
I would like the complete gmvis reports for three different
I would like the complete gmvis reports for three different VINs, as they are used and I would like to know what the maintenance history of these was before committing to buying one. 1G1RB6S51HU113742… read more
GM Bob
GM Bob
Automobile Technician
High School or GED
1,035 satisfied customers
Anti freeze leak toward the rear passeger side. 9 years old
i know it is anti freeze. i put cardboard under it to see the type of fluid. there is a strong odor of antifreeze… read more
Chris (aka- Moose)
Chris (aka- Moose)
GMC Technician
51,649 satisfied customers
I have a 2002 gmc envoy 4.2 and I'm replacing the engine and
I have a 2002 gmc envoy 4.2 and I'm replacing the engine and I'm gonna lower the transmission but on the transmission brace at the back on the driver side there is a what looks like a Evap box that is… read more
David Craig
David Craig
OWNER/MECHANIC
Associates
5,284 satisfied customers
PROBLEM WITH BCM LOCATION OF BCM 2000 C3500 7.4L REPLACED
PROBLEM WITH BCM LOCATION OF BCM 2000 C3500 7.4L REPLACED FUEL SENDING UNIT 60 PSI NOW ENGINE STARTS THEN DIES TRY TO RESET PASSLOCK SECURITY LIGHT WILL NOT GO OFF AFTER 10 OR 15 MINS TRUCK HAS BEEN D… read more
Amedee
Amedee
GMC Technician
Vocational, Technical or Trade Scho
455 satisfied customers
What is the name of the part that the blend door actuators
what is the name of the part that the blend door actuators are connected to on a 03 H2 hummer? … read more
Gary
Gary
GMC Technician
Vocational, Technical or Trade Scho
1,537 satisfied customers
Diesel is leaking from the optic sensor of fuel driver of a
diesel is leaking from the optic sensor of fuel driver of a 1995 GM 6.5L turbo diesel in my Trek motor home Can the cover be removed and the sensor tightened to stop the leak? … read more
Jesse Southard
Jesse Southard
7 satisfied customers
Engine has ticking sound all the time except when
Engine has ticking sound all the time except when excelerating. … read more
Mechanic01
Mechanic01
2,596 satisfied customers
Looking for stereo wiring diagram for 2010 gmc Yukon slt
Looking for stereo wiring diagram for 2010 gmc Yukon slt with Bose speakers. Need to find which wire to tap for remote power on to amp … read more
Dan
Dan
Automotive Technician
Vocational, Technical or Trade Scho
25 satisfied customers
It's not a GM, Hummer H2, right front brake. Not sure, can
It locks up on a single pedal press, releasing as soon as I open the blead screw… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
My 6-speed allison (early 2007) is leaking oil out of the
my 6-speed allison (early 2007) is leaking oil out of the switch on the lower right side of the trans … read more
roy
roy
Associate Degree
3 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