Ford Tech at the dealership is dumb founded - Auto Start/Stop issue

[outlier]

I have a Ranger XLT Tremor (build November ‘21)
that started enabling/disabling the “Auto Start/Stop” function randomly by itself!!

Symptoms are repeated “Auto Start/Stop disabled by Switch” & “Auto Start/Stop enabled by Switch” messages in the dashboard in a loop, along with the actual auto start/stop switch light turning amber & then off & then on again with the corespondent dash message!!

My ford tech assumed that it was the actual switch that was shorted or sticky, so he replaced that but the symptoms came back right away. Before the replacement the symptoms would stop by itself after a while. Now it’s there constantly. Ford service manual says to replace the FICM as next step but he’s telling me that he doesn’t agree with that because in his opinion FICM shouldn’t have anything to do with this!

As for the truck itself, the few electrical/electronic changes that may have any relevance to this issue are mostly OEM ford parts and I’ve installed them according to Ford’s service manuals to the T. They’re as follows:

• Ford Performance Tune (though I am using WIX air filter instead of the K&N it came with)
• Ford trailer brake controller
• Ford (U1000) dashcam with Ranger specific OBDll pass-through harness
• WARN winch connected to Upfitter switch# 1
• Ford Performance hood mounted off-road lights to Switch# 2
• Eaton OEM electronic front locker to Switch# 3.
• Ford touch activated bed lamps
• Ford 12VDC bed outlet
• Auxito LED replacement for fog & headlamps, turn signals, side markers & rear bed lights
• Bambi mode enabled & turn signal rapid flashing disabled via FORScan
  
  These changes were done at least over a year/5000 miles prior to this issue and I doubt has anything to do with it but thought I should list them anyway for disclosure.
  
  Any suggestions or insight? Truck is still within the 30K miles/36 months bumper-to-bumper warranty.
  (Apologies for such long post and thanks for reading it)

I have a 2019 Ranger xt stripped no options and the auto stop/start stopped working after a few months. It turns itself on or off at random times. Decided diagnosing the problem was too expensive and above my skill level. I would be interested in the solution once you fix the problem.

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[shovonmshahriar]

Just got off the phone with the dealership and they basically has no solution for me. They said they contacted Ford after the repair steps (replacing FCIM and switch module) are followed but symptoms remain. It’s been a week and no response from Ford. I forwarded to the dealer’s mechanic every suggestions and ideas that were shared here by you good folks in the forum, my sincere gratitude.
Now the question is what’s my next step/options? The truck is under full bumper to bumper warranty.

 

[airline tech]

Just got off the phone with the dealership and they basically has no solution for me. They said they contacted Ford after the repair steps (replacing FCIM and switch module) are followed but symptoms remain. It’s been a week and no response from Ford. I forwarded to the dealer’s mechanic every suggestions and ideas that were shared here by you good folks in the forum, my sincere gratitude.
Now the question is what’s my next step/options? The truck is under full bumper to bumper warranty.

Its either a wiring issue between the Switch and FCIM or bad ground at the switch

or

Communication (Data Bus) MS-Can Bus
If there are no other data bus or module issues are present, then check Connector C211
C211 to FCIM - Wiring Check
C211 to the Splice Points - Wiring Check

HOT - PAY ATTENTION TO THIS
I just noted how the Trailer Brake Controller and the Tailer Harness, tie into the MS-CAN bus, this is a POINT TO NOTE.

Now being that you have a Trailer Brake Controller Installed, I have a hunch that this is where the issue may be at.
The ASS is deactivated or inhibited when a trailer is connected.
Note how the data bus communicates to the TRM, this is looking at (Trailer Connected) signal through the trailer tow connector (Input) in the TRM

Now look at where the Trailer Brake Controller - Taps into the circuit
Upper Left (Taped to Harness) is the tap source for the TBC.

Try Disconnecting the Trailer Brake Controller and see if the issue is resolved.
Check the Trailer Connector mainly the Ground for it.

If this is data bus related, the issue will most likely be here as the system thinks you have a trailer connected.
Now I am not sure is this disable the switch or just disables the ASS from enabling (Green)

The flickering of the switch (enable / disable) which appears to be wiring between the switch and the FCIM, could possibly be a misleading event.
and a possible secondary source of failure and a separate input could very well be the truck thinking a trailer is connected.

And with this issue pointing greatly towards a bad ground, I would check Ground for the Trailer Harness G400 and Ground G302 for the TRM

I am giving this a What IF? Outside the Box thought

I do not have ASS or a TBC, so I can only rely on wiring diagrams.

Or:
Just another outside the box thinking here and it depends on how they did the PMI software load on the NEW FCIM.
If they downloaded the OLD FCIM software to the Laptop and Reinstalled the software to the new FCIM
The software could be Corrupt.

If they view the As-Built Data for the FCIM
Look at: This Data String - This is the string that Enables and Disables the Switch Input
7A7-01-01 ---- 0076-81DC-1497 - Enabled.
7A7-01-01 ---- 0076-80DC-1496 -Disabled

Ensure the data line = ENABLED

Plus check the IPC: for Correct Data String:
720-01-01 - --- 2FOF-3464-7271 - Indication Enabled
720-01-01 -----2FOF-1464-7251 - Indication Disabled

Ensue the data line = ENABLED

I believe I have covered ALL possibilities here for the issue.

 

[shovonmshahriar]

Thank you @airline tech !

one thing I also forgot to mention, the dealer keeps asking me about the Ford Performance Tune that is installed in the truck. Apparently after installing the new FCIM, everything works fine with the stock tune but as soon as they switch to the Performance tune the ASS switch becomes “inert”! The repeated dash messages (enabled/disabled) is gone after FCIM replacement. I’ll have to ask the tech specifically what is the exact symptom now after they replaced the FCIM.

Thank you again for you inputs.

 

[airline tech]

I do not know about the Tunes:
and I do not know the specific data lines in the PCM (As-Built) files
But:
I think these 2 data lines are the PCM data lines for the ASS, I have no way to confirm this, and I am only using various sources for what each PCM data lines actually set (configure)
I have broken down all the modules except the PCM Data in my research.

7EO-165-31
4B42-3350-2072 - ASS Enabled
4E42-3350-20A2 - ASS Disabled

7EO-165-33
5544-2020-201F - ASS Enabled
4641-2020-20FE - ASS Disabled

It is quite possible that the Tune has corrupted these 2 Hex-Data Lines, or the tune has these programmed to disabled.
Might be worth looking at these data lines - to confirm.

 

[shovonmshahriar]

Update on the status: Auto-Start/Stop issue resolved. It was poor workmanship of the technician!!! The technician pinched a connection between the switch module and FCIM when replaced those. That’s why the new FCIM wasn’t receiving any signal from the new switch module, causing all kinds of confusion. ASS works fine now, no issues as far as ASS goes. BUT, there’s a new issue!!

The turn signals aren’t working at all (that’s all I’m told ATM, I don’t know the exact symptoms yet). Technician saying the BCM needs reprogramming!

I can’t figure how BCM got affected when he was working on ASS!

 

[PltFX4]

I have a 2019 Ranger xt stripped no options and the auto stop/start stopped working after a few months. It turns itself on or off at random times. Decided diagnosing the problem was too expensive and above my skill level. I would be interested in the solution once you fix the problem.

As noted in another thread, a low battery charge will turn ASS off till it is fully charged again (at least it does on my 2019 Lariat). I would not imagine low battery would cause the cycling of the switch as the OP is see, but maybe(??).

Given all the "extra stuff" the OP has on his rig, there is likely some extra parasitic draw when turned off(??)

 

[shovonmshahriar]

I have a 2019 Ranger xt stripped no options and the auto stop/start stopped working after a few months. It turns itself on or off at random times. Decided diagnosing the problem was too expensive and above my skill level. I would be interested in the solution once you fix the problem.

are your symptoms similar to what is shown in this video?

 

[Frenchy]

I would say, the Tech is on the right path but needs to follow through with his assessment of the switch.

Yes - The FCIM has something to do with it.

If he pulls up the wiring diagram, he will see that the switch has 3-Wires for control & indication.

Now I cannot confirm this, since there is not a full description of how it operates (Internally - FCIM)
But I believe that when you push the switch (Momentary) it tells the FCIM you are in disabled (selected-mode) and it holds that (within the FCIM) until a power cycle has been performed or you press the switch again (to enable)

The (power cycle) event (shut off truck and restart) is the reason for having to press the switch (if you HATE the ASS System) Every Time you start the truck.

So, YES the FCIM can be the issue here.

Now to focus on what's happening, the FCIM sees that the switch is being pressed - multiple times in succession. (Enable/Disable)

So, there are 3-Wires on that switch connector that control that information to the FCIM
1. Switch Input - To FCIM
2. Indicator - Light (Feedback from FCIM)

The above 2 - go into an Inline connector between the FCIM & Switch
If there is a bad connection here, it could be seeing that the switch is being pressed (Circuit Disruption)

3. Ground, this is where I would focus, I have a feeling you have a bad ground, causing the issue.

With getting the same symptoms after the switch replacement but more prevalent, then I highly suspect a bad connection in the switch connector, most likely the ground wire.
as he disturbed the connector (Removed & Reinstalled)

So, before condemning the FCIM, do some simple wiring checks as I strongly feel that is the issue here.

One thing I would think to do before replacing the FCIM is to use the appropriate scan tool and reset it using as built data from Ford. It should not affect the tune whatsoever and sometimes doing a reset of a module is helpful. I know I had to do it with my PCM when my transmission wanted to act up momentarily. That'd be my thought

 

[shovonmshahriar]

One thing I would think to do before replacing the FCIM is to use the appropriate scan tool and reset it using as built data from Ford. It should not affect the tune whatsoever and sometimes doing a reset of a module is helpful. I know I had to do it with my PCM when my transmission wanted to act up momentarily. That'd be my thought

That’d be ideal. ASS issue resolved as posted in the message #21 above. Now we are dancing with the BCM. Somehow the technician managed to screw that up!!

 

[shovonmshahriar]

Got a call from the dealership, the tech flushed/reprogrammed the BCM but no results. The truck still has no turn signals!

 

[outlier]

are your symptoms similar to what is shown in this video?

are your symptoms similar to what is shown in this video?

Thanks, I will check my battery and see if that clears up the mystery. I miss my old Ford Ranger sans computers and easier to diagnose

 

[moorejl57]

Unfortunately, not many technicians have good electrical troubleshooting skills. Even though I am a software engineer, I get called into the fab at work to troubleshoot the laser micro-machining tools. I used to be a microwave tech at a military contractor where I learned how to troubleshoot complex systems. It's a skill that takes a lot of experience to get good at.

 

[airline tech]

Got a call from the dealership, the tech flushed/reprogrammed the BCM but no results. The truck still has no turn signals!

The tie in is the Hazzard Switch, at the FCIM , this is where they need to look

 

[airline tech]

I have a hunch that the Switch and FCIM are not the root problem (original issue)
The switch was replaced and created another issue.
My thoughts point towards the Trailer Brake Controller or Inline connector going to the Rear Taillights affecting both the ASS and Turn Signal Circuits
or
Since they have had the FCIM off, then possibly missed reconnecting the Hazzard Switch connector.

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