Various module communication issues and J2534 adapter suggestion

[whtbronco]

BLUF: looking for a J2534 pass through adapter verified to work with the Gen 2 Expeditions for Forscan troubleshooting

Long version/story:
My wife called to say that Message Center showed Tire Pressure Monitor Fault on our 2004 EB. BTW, I think EB stands for too much crap. She was 400 miles from home and I did not send her with a scanner, oops. I figured it was likely just a TPMS sensor battery so I told her not to worry about it, she'd already checked all tire pressures. After refueling and thus restarting the fault did not return. When she got home I used my OBDII scanner and found the following DTC's.

DSM (Driver's Seat Module)
B2324 - Driver's mirror vertical position sensor circuit fault
B2320 - Driver's mirror horizontal position sensor circuit fault
B2316 - Passenger's mirror vertical position sensor circuit fault
B2312 - Passenger's mirror horizontal position sensor circuit fault

HEC (Hybrid Electronic Cluster)
U1262 - SCP data link fault

PCM (Powertrain Control Module)
B1600 - No PATS(Passive anti-theft system) ignition key transponder signal received
-Possible Reasons-
-Ignition key damaged
-PATS antenna/wiring damaged
-PCM (Powertrain Control Module) damaged

TPM (Tire Pressure Monitor)
U1041 Missing or incorrect vehicle speed signal

I cleared the DTC's and scanned it again. I repeated this process numerous times. Consistently getting the expected P1000(didn't finish test), occassionally getting B2320 and B2324 again. However, the scanner showed various systems with communication issues. Most common were EATC, 4x4, VMS and DSM, but they varied. So with that being all I could get from my scanner I grabbed the laptop with Forscan. I then learned Forscan couldn't see the modules on the MS bus unless I get a J2534 pass through adapter. I'm sure the problem on the MS bus will likely get worse so before that happens I need to get setup to identify and resolve it. I have looked all over and the only adapter that seems to consistently work on the early 200x Fords is the CarDAQ-Plus at $1780, ouch. Any suggestions on a more reasonably priced unit? Anyone have successful experience with the Mongoose-Plus that's only, cough, cough, $540?

Another day, ~100 miles and 3 drive cycles so I checked it again despite no noticable symptoms or CEL.

DSM (Driver's Seat Module)
B2324 - Driver's mirror vertical position sensor circuit fault
B2320 - Driver's mirror horizontal position sensor circuit fault

PCM (Powertrain Control Module)
P1000 - OBD Systems Test Incomplete

VDM (Vehicle Dynamics Module)
C1991 - Module Calibration Fault

I then cleared the DTC's and hit refresh. I hit refresh multiple times and got different modules showing No Fault Code|! . So I decided to read the data stream for these modules and each of would randomnly change from the correct value to N/A. This was the case for everything I would prefer not to have, 4x4 CM, EATC, DCSM, DSM, VDM, VSM, TPM, PCSM. PCM, ABS and RCM all remained rock steady reporting the correct data stream info, but I believe these are on a different bus.

Only one recent vehicle change and that was to move my stereo amp wire from under the carpet against the driver seat to the center row. I simply moved it out to the wire path along the doors. Maybe I fubar'd something as it is a rather snug fit next to the driver seat.

 

[whtbronco]

So while continuing to look for evidence of an adapter that will work I had the bright idea to try and update the driver for my OBDLink EX. I mean it is supposed to be able to read both the HS and MS bus, I'm calling BS on that, haha. The driver update didn't help, but being an IT admin I should have tried that the other day, duh.

I'm now reviewing wiring diagrams since for now I have given up on using a computer to help me troubleshoot the computer issues. My wife has started looking for a 78 Bronco to replace the Expedition. No computer needed, simple, reliable and tough as nails. These trucks have gotten so frickin expensive now days though, I guess they all have. I would love to have another 78 Bronco, but I doubt I'll be willing to pay for it despite wanting to get this computer controlled vehicle out of my life.

 

[whtbronco]

According to AllData the buses are called SCP and UBP.

SCP is for the PCM, ABS, LTPM(Low Tire Pressure Monitor) and the IC(Instrument Cluster).

UBP is for EATC(Auto Temp COntrol), 4WD, PAM(Parking Aid), ASM(Air Susp), DSM(Driver Seat), CCSM/Driver(Climate Control Seat), CCSM/Passenger, VSM(Vehicle Security) and IC. UBP is bus that FORScan is not seeing. Shame I can't just eliminate the entire UBP bus and convert 4WD to manual hubs and T-case and the HVAC to manual switches/levers.

This clearly identifies that I have an issue on both buses with common links being the PCM and IC. I'm still trying to track down additional common links, but I suspect that's it. I doubt the issue is due to the IC. Just for grins I inspected the PCM connectors and despite seeing no corrosion or dirt I went ahead and cleaned them with electronics cleaner spray, figured it can't hurt. Course it didn't help.

 

[Yupster Dog]

I'm still trying to track down additional common links

In this whole thread i have not heard you say anything about grounds.
Check your grounds everywhere.
So many diferent things wrong usually points at a lifted or intermitten ground.

 

[whtbronco]

Good point, thank you. Easy enough to check/verify and repair if needed, yet often overlooked as I have done. Sometimes I ain't all that bright .

Next up verify grounds.

 

[BlackCoffee]

I would check the grounds with so many problems. Next, go through the pinpoint tests. Unfortunately, one bad box will take out the buss. I had a bad EATC and the indications were on the transfer cases 4x4 indications.

 

[whtbronco]

Boy this is really taking some time to troubleshoot. I have checked 12 of the 18 grounds I know of. Thus far I have found no issues, but I did pull them all and clean them a bit. 4 of the grounds had some corrosion, the 2 at the headlights, the one on the front frame rail and the starter all had a bit of rust. The 3 by the PCM actually look brand new. I started at the front and I'm working my way towards the back. The rear grounds will take a few hours.

I use a turn signal harness and bulb to test grounds. A couple mechanics I used to associate with said that most test lights aren't good enough and just to use any automotive harness and buld to actually put a bit of load on it and that's good enough. it's also super cheap to make with supplies from the junkyard.

Noteworthy I think are that I have found 2 grounds that I can find no documentation to support in AllDataDIY. Being the original owner I am certain these were installed at the factory. 1 is behind the driver side kick panel, only 1 is documented and I found 2, and the other is a body to frame mesh ground strap under the passenger front foot well.

Next ground to check is G300 on the driver side B pillar. Several of the effected modules use this ground.

Well with all these modules sharing a bus it makes sense that one faulty module can impact the others. I sure hadn't considered that yet though. Thanks for the idea. I'll add the pinpoint tests on the test plan as the next step.

 

[Yupster Dog]

I use a turn signal harness and bulb to test grounds.

Or you can use Voltage Drop Test to check. All you need is a digital volt meter.

 

[Vincent Vega]

@whtbronco here is a list of grounds and locations from the shop manual. 90% chance you already have this, but just making sure. Good luck

 

[whtbronco]

@Vincent Vega , thank you sir. Yeah that's the same list I have from AllDataDIY.

Clearly I'm just blind as there are 2 listed for the driver side kick panel, G202 and G301. I guess listing them separately was enough that I didn't see it in the list. So there's only 1 that I found and don't see on the list.

@Yupster Dog , voltage drop is not something I'm familiar with, I'll look into this. I have a DVM, one of the most useful tools so gotta have it.