Good Evening,

I am getting a P0603 code on my 04 6.0PSD, Excursion. A little back story. Engine bay fire, right side battery cable shorted against oil cooler, wiring harness burnt, several connectors on right side burnt. All engine wiring harnesses replaced, FICM replace (FICMRepair.com), new stand pipes and dummy plugs, new nipple cups and o-rings, new injector o-rings, new custom made battery cables, new battery terminals, and probably some other stuff I can't remember. Batteries were out of the truck for about 3 months, put new batteries back in, reading 13.4v when truck is running and over 12v when off. Each battery has a ground to the frame, chassis and engine. Each battery cable is 00 for positive and 1ga or 0 for ground. Connectors are hydraulically pressed on and soldered with heat shrink.

I have a OBDLink MX adapter and using FORSCAN Lite on my iPad and iPhone to monitor the engine and other components. I recently updated the firmware on the adapter and made sure my app was updated. When I first got the truck running, about a month ago, I was able to use my iPad without issue. Lately, truck only has about 20 miles on it since the fire, I have been able to connect to the adapter and the app would start and connect. Within a few minutes the app would stop working and I would get an error which stated the "Unable to run data stream. Please make sure the ignition key is ON and try again", the truck is running when this happens. I have done a factory reset on the adapter. This happens with both devices, iPad and iPhone. I can connect my ScanGuageII and it will display engine water temperature but will not display engine oil temp, fan speed and ficm voltage, these are the items I have chosen to monitor on ScangaugeII, a reason why I am moving to FORSCAN.

Can someone PCM smart tell me what trouble shooting procedures I should follow to ensure my PCM is operating correctly. I am sure I have missed some information, rather tired. Anything you can suggest will be helpful. Tomorrow afternoon I am removing the grounds from both batteries, removing the left side battery and removing the PCM. I will check all of the wires, connectors and will install a new ground cable, just to be sure.

Thank you,
Jeff

 

Scangauge will display those things, and a whole lot more. Just needs to be programmed to do so. You just have to ask for the information.

FICM Vehicle Power (Volts) (Should be 12 Volts)
TXD: 07E02209CE
RXF: 0462450906CE
RXD: 3010
MTH: 006401000000
NAM: FVP


FICM Logic Power (Volts) (Should be 12 volts)
TXD: 07E02209CF
RXF: 0462450906CF
RXD: 3010
MTH: 006401000000
NAM: FLP


FICM Main Power (Volts) (Should be 47-48)
TXD: 07E02209D0
RXF: 0462450906D0
RXD: 3010
MTH: 006401000000
NAM: FMP

Engine Oil Temp
TXD: 07E0221310
RXF: 046245130610
RXD: 3010
MTH: 00090005F05F
NAM: EOT

Fan Speed Sensor (RPM)
TXD: 07E022099F
RXF: 04620509069F
RXD: 3010
MTH: 000100040000
NAM: FSS

 

Yes, thank you, I know it will display much more but those are just the 4 things I have chosen at the moment. My only issue with scangauge is the fact it will only display 4 things at a time and it doesn’t log the data so it can be downloaded later.

thank you,
jeff

 

Your APP is just saying it can't see the data (e.g. HS CAN +, HS CAN -) on the OBD2 bus, no "wake up" from the PCM, nor indication its memory is alive and well....................seems you might (I'm not even close yet given the fact I'm not there) have an underlying computer (or power) related issue.

I'd walk down the PCM power feed leg first:

@ PCM Power Relay in the Central Junction Box, then downstream thru its fuse
Then @ the 1381 connector into the PCM looking for PCM Power Relay Switched Power (back probe pins 34 and 46)

Let me know if the power feed is correct and we'll walk you thru PCM troubleshooting next.........

 

ok, I can do that. Any schematic showing which pins are 34 and 46 and a schematic for the wiring showing which is the power leg? I hate electrical issues, I’m not that great at tracking them down and I haven’t put much effort into learning about them. Guess it is time for that to change.

thanks for the help

 

Ok, found which pins are which.


I used this connector, voltage was 12.4v. I checked the wires and have looked at each fuse and nothing was blown. Still looking for the PCM relay. Once I find it I’ll let you know what I find.

 

Before reconnecting the PCM I added a 12ga wire from one of the PCM mounting bolts to an existing ground strap near the PCM. I reconnected everything, connected the batteries and started the truck. I plugged in my Scangauge II and it displayed all 4 items. I cycled through the options and each displayed. I also noticed the ABS light, which has been on for some time, went out. I read in another thread how that can be an indication of an issue with the PCM. I would still like to do some more trouble shooting on the PCM.

thank you,
jeff

 

well that did not solve the issue. After a couple of days my ScangaugeII started doing the same thing. It would try to connect then restart and try to connect. It seems to be intermittent because it started working again last night when I was looking for an oil leak.

anybody have some trouble shooting suggestions??

thanks,
jeff

 

If you have access to a Windows laptop, the full version of FORScan lets you see the data traffic on each individual bus. Seeing one die would at least confirm or rule out the issue but not pinpoint it.

 

Ok, I’ll see if I can get my laptop to connect to the ODBLink adapter. Sometimes that is also an issue, it won’t connect. That’s why I went back to ScangaugeII because it is hardwired and I can see when it is working and not.

 

You can get a hard wire for your laptop to run Forscan, that is what I have,and use when doing diagnostics. You get faster connection when koeo. It also has your can switch from high speed and medium. Works well.