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Jared D
Jared D, ASE Certified Technician
Category: GMC
Satisfied Customers: 1699
Experience:  Shop Supervisor at County Fleet
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2004 gmc 2500hd won't start it died. It won't turn over in

Customer Question

2004 gmc 2500hd won't start it died. It won't turn over in the dash lights seem to stay on for some reason I could turn it over if I put a remote switch off of the starter it'll turn over but won't start
Submitted: 1 year ago.
Category: GMC
Expert:  Jared D replied 1 year ago.

Hi

Let's see if we can get you going again.

First, can you check the PCMB fuse to see if it's blown?

Also, check the fuel pump relay for signs of excessive heat.

Customer: replied 1 year ago.
No it's not. Seems like I'm looked out
Customer: replied 1 year ago.
I put a new relay in no luck
Expert:  Jared D replied 1 year ago.

Verify the "IGNA" 40 amp fuse in the Underhood Electrical Center (UHEC).

Check for voltage at the Red wire at the Ignition Switch in pin F.

If no voltage is present, check pin A10 at connector C201 at the base of the steering column.

If no voltage is present, check the bottom of the UHEC for rodent damage.

Check the Red wire in 68 cavity Gray connector at pin B12.

If voltage is present, replace the Red wire circuit #142.

Customer: replied 1 year ago.
Not sure where pin f is and a10
Customer: replied 1 year ago.
40amp good
Customer: replied 1 year ago.
Not sure what the UHEC is
Expert:  Jared D replied 1 year ago.

It's in the ignition switch connector.

Expert:  Jared D replied 1 year ago.

Sorry, the UHEC is just the book's way of saying under hood fuse box.

Customer: replied 1 year ago.
put a new ignition switch in
Expert:  Jared D replied 1 year ago.

Right, pin F feeds voltage to the ignition switch.

Customer: replied 1 year ago.
red has power
Customer: replied 1 year ago.
Where is #142 red wire circuit
Expert:  Jared D replied 1 year ago.

You would only need to replace the red wire circuit if there is no voltage at the ignition switch. The #142 circuit is at the PCM.

Expert:  Jared D replied 1 year ago.

Do any other electrical circuits work? Door locks, power mirror (if equipped), power window etc.

Expert:  Jared D replied 1 year ago.

How do the IGN0 and IGN3 fuses in the under dash fuse box look? Do they have 12 volts with key on or off?

Customer: replied 1 year ago.
The Ing0 and ing3 have 14v only when turn ignition on
Customer: replied 1 year ago.
Power door locks only work when key is turned on! Power Windows work
Expert:  Jared D replied 1 year ago.

When you first turn the key to the run position can you hear the fuel pump run for a few seconds?

Expert:  Jared D replied 1 year ago.

When you jumped the starter to get it to crank did you have the key in the run position?

Customer: replied 1 year ago.
It doesn't seem like could hear fuel pump. When I jump start it with key in run position dose not run just turns over. I did have I running just for a minute 2 times and yesterday about 10-15 minutes one time than it goes like dead and can't even get it to turn over
Expert:  Jared D replied 1 year ago.

If you jumper the fuel pump relay will the pump run?

Customer: replied 1 year ago.
How do I do that
Expert:  Jared D replied 1 year ago.

Jump pin 30 and 87 together. It should run the pump.

You should also be able to jump pin 30 and 87 together on the starter relay to get it to crank.

Expert:  Jared D replied 1 year ago.

Do you have a scan tool to check for communication with the PCM and BCM?

I'm leaving the shop in a few minutes here, I might have to catch back up with you this evening.

Customer: replied 1 year ago.
That's fine I did just buy a snapon scanner just not that good with it yet
Customer: replied 1 year ago.
I Jump fuel pump couldn't hear it and I jump starter relay and it cranked!
Expert:  Jared D replied 1 year ago.

Can you command the fuel pump to run with the scan tool?

Customer: replied 1 year ago.
It says no communication
Customer: replied 1 year ago.
I did jump relay for fuel pump it runs I was doing wrong one
Expert:  Jared D replied 1 year ago.

No comms huh? Might be a PCM problem. Let me look at the schematic and see where we should look next.

Customer: replied 1 year ago.
It just cranked over about 3 revolutions and stopped dead again! Strange
Expert:  Jared D replied 1 year ago.

1. Locate the splice pack SP205, which is taped to the harness above the left side footwell light under the Instrument Panel (IP) on the left side near the back of the fuse block.

2. Remove the "Comb". Connect a scanner to the DLC. Use a suitable jumper to short pin D, a Purple wire to the Dk Green wire at pin B. Attempt to communicate with the Powertrain Control Module (PCM).

3. If communications work, use another jumper to short pins B and D to each of the other pins in SP205 one at a time. Determine which wire/module is causing the communications failure. When that wire/module is shorted to pins B and D, the scanner will go to "No Communications".

4. Go to that module for a circuit failure in the Class 2 data circuit or power or ground issue going to that particular module.

Expert:  Jared D replied 1 year ago.

My guess is that it's the IPC- Pin G

Expert:  Jared D replied 1 year ago.

If you don't get any communication in step 3, then there is probably a PCM problem.

Customer: replied 1 year ago.
Not sure what you mean can specify more! A found the connector behind fuze block going by drawing 15305291 jumper B and D
Customer: replied 1 year ago.
On the drawing where you plug scan tool in it says splice pack - SP205 miss leading,
Customer: replied 1 year ago.
on bottom of drawing
Expert:  Jared D replied 1 year ago.

That is worded kind of weird. The scan tool plugs into the Data Link Connector like normal, not the SP205. You just unplug SP205 and jumper the pins while you have the scan tool plugged into the DLC.

Customer: replied 1 year ago.
it is communicating !
Customer: replied 1 year ago.
Not sure what is next!
Customer: replied 1 year ago.
No engine codes! But there is codes on BCM - B2961, U1000, U1305, U1160
Expert:  Jared D replied 1 year ago.

Check the connector at the BCM for corrosion or water intrusion. All of those codes have to do with the BCM connector.

You should also check the ground point at the back of the engine; that point to the U1305 code. It's right at the firewall on the transmission bell-housing or the cylinder head.

Customer: replied 1 year ago.
The BCM is right at lower steering column?
Expert:  Jared D replied 1 year ago.

Just to the right of the column. Here is the replacement procedure. It shows where the connectors are. I would pull the connectors and put some dielectric grease in there and then plug them back in.

Customer: replied 1 year ago.
I took all connectors off they look fine and the terminals look good. I opened BCM up looked at both sides of board didn't see anything bad
Expert:  Jared D replied 1 year ago.

So will it crank now that the communication network is back up?

Customer: replied 1 year ago.
Should I try it with B to D jumper in? Or remove it!
Expert:  Jared D replied 1 year ago.

I didn't realize you hadn't yet jumpered the other module pins. I thought you meant it just started communicating again.

You will want to jumper the other pins one at a time to the b-d jumper until the scan tool drops communications.

Expert:  Jared D replied 1 year ago.

Whichever pin it drops communications on has a faulty corresponding module.

Customer: replied 1 year ago.
If you put one end of wire to B and other end of same wire to D . How could you tell what drops
Expert:  Jared D replied 1 year ago.

You need another wire to jump from those two to another pin in the connector. Going from B to D just wakes up the network.

Customer: replied 1 year ago.
Not sure what you mean? I jumped B and D on diagram 15305291
Customer: replied 1 year ago.
On that sp205 connector there was only a female end
Expert:  Jared D replied 1 year ago.

This should be the SP205 pin out view. This is where the jumper from b-d is currently right?

Customer: replied 1 year ago.
right
Expert:  Jared D replied 1 year ago.

I forgot the attachment.

From there you jump to each of the other pins one at a time while watching the scan tool.

Customer: replied 1 year ago.
Just so no confusion the drawing number is ***** this is the view of connector
Expert:  Jared D replied 1 year ago.

I would probably start by jumping b-d to pin g. Then check communication. The most common fault on these trucks is the IPC.

Customer: replied 1 year ago.
It's saying no communications ( portID=0x0002 BEN=G2209)
Customer: replied 1 year ago.
What a IPC
Customer: replied 1 year ago.
What is a IPC ?
Expert:  Jared D replied 1 year ago.

Instrument panel cluster. If it dropped comms when you jumped to that pin then the short is in the instrument cluster.

Customer: replied 1 year ago.
Could I try one from other gmc truck? Or are they specify to one vehicle
Customer: replied 1 year ago.
I have a 2002 sitting here
Expert:  Jared D replied 1 year ago.

The mileage is the only thing that won't be correct. It should allow the engine to start if the connector is the same on the 2002. I couldn't say off hand whether they are the same.

Expert:  Jared D replied 1 year ago.

You might even be able to start it if you unplug the cluster connector. I know the 2000 and back models will start with no cluster; never tried on a 2004.

Expert:  Jared D replied 1 year ago.

It's worth a try since you can get the cluster out in about 2 minutes on this one.

Customer: replied 1 year ago.
No luck does same thing it's dead no attemp to turn over!
Expert:  Jared D replied 1 year ago.

Disconnected or with the 2002 IPC?

Customer: replied 1 year ago.
Didn't turn over with it plugged in or unplugged
Expert:  Jared D replied 1 year ago.

Did your communication come back at the scan tool?

Customer: replied 1 year ago.
No it didnt
Expert:  Jared D replied 1 year ago.

How do the wires look under the underhood fuse box?

It's a good place for rodents to chew wires.

You can remove the plastic cover and pull the box up and see all of the harnesses underneath.

Customer: replied 1 year ago.
under hood the fuze box looks fine! It just won't turn over its like some how lost pos. or neg. to starter. I'm puzzled
Customer: replied 1 year ago.
Can you wiring schematic on the ignition switch to the starter and neutral safety switch wiring
Expert:  Jared D replied 1 year ago.

Here is the starting circuit.

Customer: replied 1 year ago.
Still trying things! Any info on 3 wires on top of ignition switch an 2 behind it they have something to do with passcode lock. Would that keep truck from not turning over?
Customer: replied 1 year ago.
I tried a new computer it did same thing
Expert:  Jared D replied 1 year ago.

I'm sorry I didn't notice your response the other day. Your question dropped onto my timed out list for a lack of rating.

I'm not showing a pats option on the 2004 2500hd. That could be wrong though. What does your key look like? Is it black with the little plus symbol on the key?

Customer: replied 1 year ago.
Where is the ground point G103?
Expert:  Jared D replied 1 year ago.

Your question has dropped to my timed out list for a lack of a positive rating. This also means that I have not been compensated for my time; we initiated this conversation a month ago.