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Jared D
Jared D, ASE Certified Technician
Category: GMC
Satisfied Customers: 1346
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: 8 months ago.
Category: GMC
Expert:  Jared D replied 8 months 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 8 months ago.
No it's not. Seems like I'm looked out
Customer: replied 8 months ago.
I put a new relay in no luck
Expert:  Jared D replied 8 months 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 8 months ago.
Not sure where pin f is and a10
Customer: replied 8 months ago.
40amp good
Customer: replied 8 months ago.
Not sure what the UHEC is
Expert:  Jared D replied 8 months ago.

It's in the ignition switch connector.

Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months ago.
put a new ignition switch in
Expert:  Jared D replied 8 months ago.

Right, pin F feeds voltage to the ignition switch.

Customer: replied 8 months ago.
red has power
Customer: replied 8 months ago.
Where is #142 red wire circuit
Expert:  Jared D replied 8 months 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 8 months ago.

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

Expert:  Jared D replied 8 months 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 8 months ago.
The Ing0 and ing3 have 14v only when turn ignition on
Customer: replied 8 months ago.
Power door locks only work when key is turned on! Power Windows work
Expert:  Jared D replied 8 months 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 8 months ago.

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

Customer: replied 8 months 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 8 months ago.

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

Customer: replied 8 months ago.
How do I do that
Expert:  Jared D replied 8 months 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 8 months 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 8 months ago.
That's fine I did just buy a snapon scanner just not that good with it yet
Customer: replied 8 months ago.
I Jump fuel pump couldn't hear it and I jump starter relay and it cranked!
Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months ago.
It says no communication
Customer: replied 8 months ago.
I did jump relay for fuel pump it runs I was doing wrong one
Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months ago.
It just cranked over about 3 revolutions and stopped dead again! Strange
Expert:  Jared D replied 8 months 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 8 months ago.

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

Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months 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 8 months ago.
On the drawing where you plug scan tool in it says splice pack - SP205 miss leading,
Customer: replied 8 months ago.
on bottom of drawing
Expert:  Jared D replied 8 months 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 8 months ago.
it is communicating !
Customer: replied 8 months ago.
Not sure what is next!
Customer: replied 8 months ago.
No engine codes! But there is codes on BCM - B2961, U1000, U1305, U1160
Expert:  Jared D replied 8 months 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 8 months ago.
The BCM is right at lower steering column?
Expert:  Jared D replied 8 months 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 8 months 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 8 months ago.

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

Customer: replied 8 months ago.
Should I try it with B to D jumper in? Or remove it!
Expert:  Jared D replied 8 months 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 8 months ago.

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

Customer: replied 8 months 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 8 months 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 8 months ago.
Not sure what you mean? I jumped B and D on diagram 15305291
Customer: replied 8 months ago.
On that sp205 connector there was only a female end
Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months ago.
right
Expert:  Jared D replied 8 months 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 8 months ago.
Just so no confusion the drawing number is ***** this is the view of connector
Expert:  Jared D replied 8 months 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 8 months ago.
It's saying no communications ( portID=0x0002 BEN=G2209)
Customer: replied 8 months ago.
What a IPC
Customer: replied 8 months ago.
What is a IPC ?
Expert:  Jared D replied 8 months ago.

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

Customer: replied 8 months ago.
Could I try one from other gmc truck? Or are they specify to one vehicle
Customer: replied 8 months ago.
I have a 2002 sitting here
Expert:  Jared D replied 8 months 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 8 months 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 8 months ago.

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

Customer: replied 8 months ago.
No luck does same thing it's dead no attemp to turn over!
Expert:  Jared D replied 8 months ago.

Disconnected or with the 2002 IPC?

Customer: replied 8 months ago.
Didn't turn over with it plugged in or unplugged
Expert:  Jared D replied 8 months ago.

Did your communication come back at the scan tool?

Customer: replied 8 months ago.
No it didnt
Expert:  Jared D replied 8 months 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 8 months 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 8 months ago.
Can you wiring schematic on the ignition switch to the starter and neutral safety switch wiring
Expert:  Jared D replied 8 months ago.

Here is the starting circuit.

Customer: replied 8 months 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 8 months ago.
I tried a new computer it did same thing
Expert:  Jared D replied 8 months 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 7 months ago.
Where is the ground point G103?
Expert:  Jared D replied 7 months 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.

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