Ford Power Stroke Nation banner
1 - 15 of 15 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I recently acquired a 2005 f250 that was doing some weird stuff. It would run for random amounts of time, then shut off like you turned the key off. You would hear a clicking noise from the relays under the dash and the CEL and glow plug indicator would come on and off like you were cycling the key. Then, it suddenly stopped running at all and not will not crank or communicate with scan tool. The fuel pump isn't running and injectors are not cycling either. Here's my checklist so far:
1) Checked all the usual fuses, all good
2) Swapped relays out from another truck
3) Manually manipulated relays to no avail
4) Verified power to PCM and good VREF at PCM connector
5) Unplugged the engine harness at pcm and it still wouldn't even turn over.
6) Found no ground from PCM to relays with ignition power, so I know the issue, but not the cause
7) Swapped out PCM from another identical truck, no luck, this pcm ran the other truck though
8) Pinout on PCM shows good pwr/grd circuits
9) Built a couple of ground wires for battery to pcm bracket and fuse box to body ground

Have good base voltage on the truck as well. I am just frustrated with it at this point and need a someone else's 2 cents, I know I am missing something.
 

·
"resident smarty pants"
Joined
·
4,815 Posts
Check the electrical supply (connector and wiring) to the fan. Sometimes (with the aging plastic in our trucks), the support for the wiring pigtail and the harness fails and the wiring gets damaged by the fan blades.

If your 12V buffered power has been shorted out because of the above (this is regulated in the PCM), it will behave as you describe.
 

·
Registered
Joined
·
3 Posts
Check the electrical supply (connector and wiring) to the fan. Sometimes (with the aging plastic in our trucks), the support for the wiring pigtail and the harness fails and the wiring gets damaged by the fan blades.

If your 12V buffered power has been shorted out because of the above (this is regulated in the PCM), it will behave as you describe.
If what bismic1 suggested, does not work, consider the GEM. Also, did you see any water or corrosion around the fuse block/ GEM connector block blades when you had the fuse block out? Another thought- when you jump across the starter solenoid high amp side, will the starter engage and crank the engine? More than one person has said that the first thing to check is the batteries for charge condition and the battery terminal connections for corrosion and tightness. Any doubt about the terminal conditions, I suggest removing the battery connectors one battery at a time and thoroughly cleaning the battery posts and the terminals. That may make a difference.
 

·
Super Moderator
Joined
·
5,271 Posts
His truck does not have a gem. Just the CJB
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #5 ·
If what bismic1 suggested, does not work, consider the GEM. Also, did you see any water or corrosion around the fuse block/ GEM connector block blades when you had the fuse block out? Another thought- when you jump across the starter solenoid high amp side, will the starter engage and crank the engine? More than one person has said that the first thing to check is the batteries for charge condition and the battery terminal connections for corrosion and tightness. Any doubt about the terminal conditions, I suggest removing the battery connectors one battery at a time and thoroughly cleaning the battery posts and the terminals. That may make a difference.
All batteries, terminals, and alternator are new. I took it out and took it apart to inspect the board, no burns or corrosion on the circuits. I provided a ground to the starter relay and it will crank over with the key.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #6 ·
Check the electrical supply (connector and wiring) to the fan. Sometimes (with the aging plastic in our trucks), the support for the wiring pigtail and the harness fails and the wiring gets damaged by the fan blades.

If your 12V buffered power has been shorted out because of the above (this is regulated in the PCM), it will behave as you describe.
Unplugged the fan, no changes. Unplugged the GPM and a few other things, no changes. One thing I forgot to mention is that when it was dying, it was throwing a pcm failure code (p0605) and a slew of glow plug codes. That is what led me to the GPM to start.
 

·
"resident smarty pants"
Joined
·
4,815 Posts
Did you inspect the wiring to the fan connector?

P0605 - Most programs will set the P0605 ROM Error code if the checksum hasn't been done properly in the calibration file. This is typically only a problem if you need to get inspected. It shouldn't have any effect on the way the vehicle runs.

Put the truck in reverse and see if you get the backup lights. The TRS is also on the 12V buffered circuit.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #8 · (Edited)
Did you inspect the wiring to the fan connector?

P0605 - Most programs will set the P0605 ROM Error code if the checksum hasn't been done properly in the calibration file. This is typically only a problem if you need to get inspected. It shouldn't have any effect on the way the vehicle runs.

Put the truck in reverse and see if you get the backup lights. The TRS is also on the 12V buffered circuit.
Put truck in reverse and immediately got a TBC fault and no backup lights. I also unplugged the pcm to see if I could communicate with any of the vehicle modules and was able to access the cluster and tbc without issue.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #10 ·
Sounds like a shorted out Transmission Range Sensor, or a short in the wiring to that sensor.

Which of the three PCM connectors did you unplug (radiator end, firewall end, or center)?
Every combination imaginable, same results no matter what, I can get into the security, tbc, and airbag module, no matter what combo I have plugged in. Still no com with PCM or ABS, so it would appear the CAN network itself is intact, we are having module issues of some sort. I got some expected CAN codes and a C2803 brake pressure transducer code out of the TBC, looked at pids and all modules are seeing battery voltage. Everything pins out correctly at the pcm plugs for grd/pwr/vref and all appropriate power circuits for the CJB at the main power plug on it.

I unplugged the trans plug from the pcm and still had no change, so I would think that would rule out the trans harness/range sensor short since it still wont communicate with the pcm. I pinned out the egr, fan clutch, and a few random sensors and got VREF and 12v where appropriate.

If I had hair, I would pull it out at this point. My next step was to start back tracing circuits at the CJB I can't really manipulate, like the fuel pump, and see what's missing to make it go (which I would assume is going to be switched GRD from the pcm and see what it does.

Any input is greatly appreciated.
 

·
"resident smarty pants"
Joined
·
4,815 Posts
That is why I was asking about which PCM plug you disconnected. The result should be a little bit different with each one unplugged, but you should see SOMETHING different happen.

Yes, the fuel pump relay is actuated by the PCM applied ground. Just like the IPR valve, starter relay and the fan clutch operation.
 

·
"resident smarty pants"
Joined
·
4,815 Posts
My guess would be the CJB, after seeing all of what you have tested. I am heavily basing this guess on the fact that a "known working" PCM acted the same way in your truck as its own PCM.

I believe that CircuitBoardMedics can repair failed CJBs.

Any signs of water exposure to it?
 

·
"resident smarty pants"
Joined
·
4,815 Posts
Oh, btw - the fuel pump not running usually is a fuse 2.22 issue . Are you absolutely sure that this fuse is good?

TRS issues will prevent a crank and not produce the backup lights, but the fuel pump should run even when the TRS has issues.

If V-Ref issues exist at sensors, then unplugging the engine harness should return the starter function AND the fuel pump operation.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #14 ·
My guess would be the CJB, after seeing all of what you have tested. I am heavily basing this guess on the fact that a "known working" PCM acted the same way in your truck as its own PCM.

I believe that CircuitBoardMedics can repair failed CJBs.

Any signs of water exposure to it?
No water, she was spotless minus some dust. I have another 2005 sitting out here I will borrow the JCB off of tomorrow and she what happens.
 

·
Registered
Joined
·
14 Posts
My guess would be the CJB, after seeing all of what you have tested. I am heavily basing this guess on the fact that a "known working" PCM acted the same way in your truck as its own PCM.

I believe that CircuitBoardMedics can repair failed CJBs.

Any signs of water exposure to it?
I used Fordfusebox.com I learned my lesson on trying to save a dollar if you decided to replace your cjb.
 
1 - 15 of 15 Posts
Top