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 GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29427
Experience:  GM Grand Master Technician 2007. 14 years experience.
10949255
Type Your Chevy Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

We have a Chevy silverado 1 ton dump truck that won't crank.

Customer Question

We have a Chevy silverado 1 ton dump truck that won't crank. We have power and replaced the pass lock sensor and still have no crank. Starter has been replaced, battery connections have been checked, we have reset the pass lock sensor using the key, we have checked fuses and still have no crank. What should we do next?
Submitted: 11 months ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 11 months ago.

Hi there, I am Cam. Sorry to hear about this issue.

Is this a early 2007 or late 2007?

Customer: replied 11 months ago.
Early, march of 2007
Customer: replied 11 months ago.
Are you still here?
Customer: replied 11 months ago.
Hello??
Customer: replied 11 months ago.
Does the starter fuse have power to it even when the truck is off?
Expert:  GM Tech (Cam) replied 11 months ago.

Sorry, driving to work.

What's your vin?

The crank fuse in the dash should only get power with the key in start.

Try removing the starter relay, the wire jumper the pins to correspond to 30 and 87 stamp on the bottom of the relay. It will be opposite corners to each other. This should make starter turn. Can you tell me if it does?

Customer: replied 11 months ago.
1GBJC34K7E530754, working on the jumper wire now
Customer: replied 11 months ago.
That did not make the starter turn.
Expert:  GM Tech (Cam) replied 11 months ago.

Ok, as bad as it sounds, that tells me its not the computer. I need to verify that you made sure to use the proper terminals. Often people forget that looking at the bottom of the relay will be a mirror image to the fuse block. Please verify and if you did it correctly, tell me if one of those 2 pins have power all the time.

Customer: replied 11 months ago.
Ok yea you are right we got it to turn the starter over
Customer: replied 11 months ago.
What should we try next? And we cannot locate the crank fuse in the dash fuse box.
Customer: replied 11 months ago.
one of the two pins did have power all the time
Expert:  GM Tech (Cam) replied 11 months ago.

Ok, so one moment, pulling up the schematic again.

Expert:  GM Tech (Cam) replied 11 months ago.

You said you replaced the pass lock sensor, is this the black ring module around the key?

Customer: replied 11 months ago.
Expert:  GM Tech (Cam) replied 11 months ago.

That is a module that needs to be programmed using the GM programming server and programming tool. A simple repeal will not do that. There is nothing I Can do to help you program that over the internet. Do you still have the old one?

Customer: replied 11 months ago.
we still have the old one
Expert:  GM Tech (Cam) replied 11 months ago.

Put that back in please, then do a reset.
Take the battery cables off the battery, hold the ends together for 10 seconds then attach them to the battery and see what happens. This will reset the whole vehicle.
If you have 2 batteries, then remove both and touch only one set.
This reset is more about touching the cables together when off the battery than taking them off. The act of touching them drains the capacitors and forces it to reset.

Then after that, have someone hold their finger on the relay of the starter and see if it clicks. If not then I would look at the ignition switch itself. Its about 35$ to replace and usually the issue on these ones. That module you replaced is the passkey 3+ module and rarely do they fail.

Customer: replied 11 months ago.
If the pass lock is preventing the start sequence will the pass lock idiot light on the dash, the pad lock around the car, be showing on the dash steadily, or will it go out after a few seconds after the key is turned on?
Expert:  GM Tech (Cam) replied 11 months ago.

Its not pass lock though, its passkey, different system.

Try swapping and see.

Customer: replied 11 months ago.
After putting the pass lock sensor back in and touching the disconnected battery cables together. The truck started
Customer: replied 11 months ago.
The battery needed a boost from us messing with stuff so much but other than that it seems to be working properly now
Customer: replied 11 months ago.
Is there anything else we should to do now that we have the truck running?
Customer: replied 11 months ago.
I do have one more question fuse 54 Seo b1 (15a) and fuse 58 ECM-ign (15a) were both blown, what if anything does that tell us about what just happened with the truck. We're trying to figure out what caused this issue to begin with
Customer: replied 11 months ago.
Are there any known grounding problems with this particular model/year truck that you are aware of?
Expert:  GM Tech (Cam) replied 11 months ago.

The ignition switch are common for this. There is a special resistor inside and it may have changed.

It’s a messed up system, RFID chip in the key and a modified pass lock system IN the ignition SWITCH. I bet the relearn you did on that helped that.

Replace the switch.

Customer: replied 11 months ago.
We apparently didn't fix the truck, it died out on the road, any ideas what it could be?
Expert:  GM Tech (Cam) replied 11 months ago.

OK, what codes are currently set?

Customer: replied 11 months ago.
I'm not sure what you mean. Like warnings on the dashboard? Or ?
Expert:  GM Tech (Cam) replied 11 months ago.

No, codes stored in the computer. We must scan to to see what codes are now set. I feel that we might be spinning our wheels until we do that.

Customer: replied 11 months ago.
How do I scan to see what codes are set?
Expert:  GM Tech (Cam) replied 11 months ago.

You need a scanner. IF you don't have one, a simple reader called BlueDriver can be used. It uses an app through your smart phone to connect to the vehicle and will scan all system modules. Its 99$ on amazon and does most every vehicle from 1995 to present.

Customer: replied 11 months ago.
Same scanner they have an autozone or any of the automotive stores?
Expert:  GM Tech (Cam) replied 11 months ago.

The scan tool many of the part stores may only read engine codes. The little one I suggest will read all system codes. Of course the best would be to have a GM dealer scan it but that does defeat your coming here.

Customer: replied 11 months ago.
We can't keep it running, the ecm/ign fuse keeps blowing and the truck shuts off. It will run for about 1/4 mile and then shut off, once the fuse is replaced it will start up but then shut off again
Expert:  GM Tech (Cam) replied 11 months ago.

Ok so the fuse pops, that is actually good. IT gives us a direction. Something on that circuit is pulling too much power. That fuse feeds the ECM, the Fuel pump control module and the transfer pump if you have 2 fuel pumps. WE need to trace down that wire and find if its shorted to ground anywhere. If not then its one of those three items. Attached is the schematic.

Customer: replied 11 months ago.
Would having it scanned like you said isolate which of those three options or could be?
Expert:  GM Tech (Cam) replied 11 months ago.

It's possible, if it's only drawing too much or shorting to the frame then no. The fuel pump control modules are common for issues on these, corrosion resulting from water getting through the back. Let me add that with it running for a bit then popping the fuse, it does not sound as much like a short on the frame and more like a module drawing too much fuel.

Customer: replied 11 months ago.
Where are the fuel pump modules? Are they on the pumps or somewhere else?
Customer: replied 11 months ago.
The rear fuel tank supply lines have been disconnected since last winter due to corrosion. The plug and wiring to the rear fuel tank seems intact and is plugged in. Could the rear tank trying to transfer fuel be the issue? If so can we simply disconnect the rear tank wiring?
Expert:  GM Tech (Cam) replied 11 months ago.

The module is near the back. Usually a box on the frame with a large connector out of the centre. Being a dump truck it might have been moved. Yes you can try disconnecting the rear pump but it might disable your fuel level sensor and show empty but for testing this is a good idea.

Customer: replied 11 months ago.
Do you have a wiring diagram of the rear fuel pump plug??
Expert:  GM Tech (Cam) replied 11 months ago.

Here it is.