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 Daniel Wilson Your Own Question
Daniel Wilson
Daniel Wilson,
Category: Chevy
Satisfied Customers: 5569
Experience:  Owner at DJ Wilson
65405794
Type Your Chevy Question Here...
Daniel Wilson is online now
A new question is answered every 9 seconds

I have a 1996 C3500 6.6 Diesel, Three scan tools will not

Customer Question

I have a 1996 C3500 6.6 Diesel, Three scan tools will not communicate with the truck. One thing I found is that the number 5 pin signal ground is not grounded. Can I run a new ground for this pin.
Submitted: 1 year ago.
Category: Chevy
Expert:  Juan Crespo replied 1 year ago.

Hi there.

Perhaps I can help. Can I ask what is it you're trying to diagnose?

Customer: replied 1 year ago.
My scanners with not do any kind of diagnose with the truck all 3 will power on but no communications. same as my first question.
Expert:  Juan Crespo replied 1 year ago.

Based on your reply, I don't think I can help you. I'll opt out so others can try. Please don't rate or reply until another expert responds or the site will cycle this back to me.

Expert:  david craig replied 1 year ago.

Hi Im David , so you're not getting a ground on pin 5 of the dlc?

Expert:  david craig replied 1 year ago.

hello?

Expert:  david craig replied 1 year ago.

do you still need assistance?

Expert:  david craig replied 1 year ago.

hello?

Customer: replied 1 year ago.
i still need help was out of town for a few and no ground on pin 5 of dic
Expert:  david craig replied 1 year ago.

OK. im going to pull up a print and we'll get this thing fixed.

Customer: replied 1 year ago.
sounds good to me this truck is driving me crazer
Customer: replied 1 year ago.
the main thing that I need is for the abs pump to cycle to bleed the brakesBut the new scaner that will do the job will not connect to the truck
Expert:  david craig replied 1 year ago.

ok. there only thing it says for 5 is its a signal ground and doesnt show where it goes. it obviously has to go to the pcm so ive attached the pcm pin outs and the only grounds are on connector c3. i believe thats going to be where it goes.

Customer: replied 1 year ago.
Thanks for your help will check it out tomorrow and will let you know what happens.
Expert:  david craig replied 1 year ago.

you're welcome. its gotta be broken between the dlc and pcm

Expert:  david craig replied 1 year ago.

any luck?

Customer: replied 11 months ago.
sorry about the late response but I had a radiator tank split and I got second-degree burns on my right arm,so I have not been able to work. I am starting back to work on it today. Will let you know when I find the problem.
Customer: replied 11 months ago.
I check the ground wires on C3 # 6&7 and they are grounded
Expert:  david craig replied 11 months ago.

ok, let me get home and ill dig in ti this

Expert:  david craig replied 11 months ago.

gotta hit the sack. ill be back on tomorrow morning.

Customer: replied 11 months ago.
when are you going to answer my question
Expert:  david craig replied 11 months ago.

sorry, been in hospital with 4 tia's ......ill opt out and let another tech answer. please dont respond back as it will send the question right back to me.

Expert:  Daniel Wilson replied 11 months ago.

Hi my name is***** will be glad to help. When you say #5 is not grounded.... What connector and what pin exactly? C1. C2. C3, etc? Pin A5, C5, D5, etc? Let me know

Customer: replied 11 months ago.
5 on the obd port my scanners will power up but no communication with the the truck
Expert:  Daniel Wilson replied 11 months ago.

Thanks for the update. #4 and 5 should be grounded. Yes you can run a separate ground to see if it resolves your problem. Let me know

Expert:  Daniel Wilson replied 11 months ago.

Click here for the pinout.

Customer: replied 11 months ago.
I ran new wires to pin 4&5 to ground but still no communication with the the truck
Expert:  Daniel Wilson replied 11 months ago.

If you have power at 16 then check the wiring for the data connections between the PCM plug and the diag connector for continuity.

Expert:  Daniel Wilson replied 11 months ago.

if okay then I would have to say it is an ECM/PCM problem

Customer: replied 11 months ago.
16 has power can I run a wire from the obd port to the PCM . If so witch plug and wire do I use