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Ryan Schott
Ryan Schott,
Category: GMC
Satisfied Customers: 83
Experience:  technician at Demarois Buick Gmc
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GM silverado 2500hd: 2004 chevy 2500 hd. drove to gas station,

Customer Question

2004 chevy 2500 hd. drove to gas station, put in half a tank, went to start engine....no crank. dash background lights and chime came on but no odometer, no prndl lights, no gauges are functioning and no crank. radio, hcac headlights ....everything works otherwise. battery 13.23volts
Submitted: 1 year ago.
Category: GMC
Customer: replied 1 year ago.
(Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
it said I would have a response in 8 minutes, we are going on 23 minutes and no response.....not off to a good start
Expert:  Amedee replied 1 year ago.
Hello and welcome! Sorry you did not get a reply sooner. I just came on line and saw that you were waiting for a reply. Are you looking for some possible causes or would you like me to walk you through this diagnoses?
Customer: replied 1 year ago.
Yes please, thank you
Expert:  Amedee replied 1 year ago.
NO problem! I am glad to help! I will need to know if you would like some possible causes or if you want me to walk you through this diagnoses.. because there is a big difference here. If you would like I can explain how this system works and what I think is going on here.
Expert:  Amedee replied 1 year ago.
Keep in mind, if you would like to speak on the phone at any time, please fee free to request a phone call and I can call you right now.
Customer: replied 1 year ago.
Diagnosis please. I checked the pcm ground on right rear cylinder head and under the drivers side door on the frame, replaced the electrical ignition switch. No change problem still exists
Expert:  Amedee replied 1 year ago.
Ok, what we need to do is start by clearing all codes in the computer. Then try starting the engine to see which code or codes come back first.
Customer: replied 1 year ago.
I did that, no codes came back
Expert:  Amedee replied 1 year ago.
The U codes are communication codes. The B codes are body codes. Which modules on board the vehicle will not communicate?
Customer: replied 1 year ago.
This is beyond me, im just a transmission rebuilder. What ever module controls the digital odometer and prndl indicator is my guess because they are not powering up. I verified voltage at all ignition, accessory, 12+ and the crank wires on the switch and all tested good
Expert:  Amedee replied 1 year ago.
Can you communicate with the instrument cluster using your scanner?
Customer: replied 1 year ago.
No I cannot connect to it with scanner. It says there's no communication and to ensure my scanner is plugged in. Also 2 dtcs came back in the pcm. U1026 and u1041
Expert:  Amedee replied 1 year ago.
So which modules can you communicate with? The PCM and or the BCM?
Customer: replied 1 year ago.
Heres the modules i can comminicate withPcm
Bcm
Both door modules
Heating and air conditioning
SIR
ABS
VSES
TPMS
EHPS
Expert:  Amedee replied 1 year ago.
But not the cluster? If this is the case, then the instrument cluster might just be bad causing your no crank condition. Try disconnecting it and see if there is any improvement..
Customer: replied 1 year ago.
Bcm has a class 2 data link malfunction dtc u1000
Expert:  Amedee replied 1 year ago.
YUP! This is a communication issue
Customer: replied 1 year ago.
I disconnected the ipc, turned key on and still no crank
Expert:  Amedee replied 1 year ago.
Ok, check to see if the MAP sensor is getting 5 volts to it on the gray wire with the key on.
Customer: replied 1 year ago.
Yes it has 5.02 volts
Expert:  Amedee replied 1 year ago.
And there is no anti theft or security lights on or flashing on the dash with the key on?
Customer: replied 1 year ago.
No the only light is check engine light and ipc backlighting
Expert:  Amedee replied 1 year ago.
Ok, plug the cluster back in and see if the starter will engadge if you ground the starter signal wire between the PCM and starter relay.
Customer: replied 1 year ago.
Which wire is that?
Expert:  Amedee replied 1 year ago.
It is a yellow wire with black stripe. It goes from the PCM to the starter relay. If by grounding this wire allows the engine to crank over, then we know the issue with with the PCM or prior to the PCM. We would then need to check the inputs to the PCM with the key on and possibly the other modules on board the vehicle if they are shorting out the BUS circuit. Sometimes you can disconnect one module at a time to see which one allows the engine to crank over. The last module you disconnected is the culprit. If you want to check the inputs to the cluster, here is the inputs that need to be checked. Be sure to run this test with the key ON. Verify battery voltage at the Orange wire at pin B11 all the time. Verify battery voltage at the Pink wire at pin B9 when the key is on. Verify a good ground on the Black/White wire at pin B12. Verify scan communications with the ECM are lost when the Gray wire at pin A6 is grounded. If OK replace the IPC.
Expert:  Amedee replied 1 year ago.
I am going to log off line for a little while. I will check back with you shortly. Let me know what you find!
Customer: replied 1 year ago.
I followed your diagnostic instructions exactly and it led me to replace the IPC got IPC programmed at the dealership still have the same problem somewhere you missed a step and cost me hundreds of dollars today but I followed your directions exactly
Expert:  Amedee replied 1 year ago.
Hello! Justanswer.com is not to be used as a substitute for a full blown diagnoses on your vehicle. This web site is for INFORMATIONAL PURPOSES ONLY.
Expert:  Amedee replied 1 year ago.
.
Expert:  Amedee replied 1 year ago.
You expressly release Just Answer! (including our officers, directors, and employees) and the Specialists from any liability of any kind that results from your use of or reliance on any of the responses given on the site. The site and the services provided by Just Answer! are provided "as is" with no warranty. Just Answer! is not responsible for the quality of information given by Specialists on the site and makes no representations or warranties regarding the qualification of a Specialist in providing responses. Responses and comments provided on Just Answer! are general information and are not intended to substitute for informed professional advice (such as medical, legal, investment or accounting) and do not establish a professional-client relationship. Please read carefully the Terms of Service.
Expert:  Amedee replied 1 year ago.
In other words.. This web site is for INFORMATIONAL PURPOSES ONLY.
Customer: replied 1 year ago.
You said " If OK replace the IPC" if you can't stand by your work the very end then what makes you an expert? You asked I I wanted possible causes or a diagnosis. I feel you steered me in a wrong direction, I feel you didnt read my whole question from the begining due to the redundant questions you asked that had you read it all you wouldn't of had to ask. I'm not satisfied and I'd like a true expert to assist me from here.
Expert:  Amedee replied 1 year ago.
Sure thing.
Expert:  Ryan Schott replied 1 year ago.
Have you looked at the park position switch on the side of the transmission? I would remove its connector,which may be difficult as they sometimes get a little melted in, and look for water intrusion.
Customer: replied 1 year ago.
Hi ryan, thanks for your response and willingness to help I have already checked that it is not the issue background on me ASE Master Certified been expired for about four years transmission shop owner and Rebuilder since 2007 however it then a professional in the industry since 1999 so needless to say this one's really got me stumped
Expert:  Ryan Schott replied 1 year ago.
Can I get your VIN so I can look up the RPOs so I know I'm looking at the correct diagrams?

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