Posts: 406
Joined: Mon Jan 21, 2013 8:58 pm
Location: So Cal

Re: Stop Safely Now Warning

Thu Jun 13, 2019 4:07 pm

Here's some comments from my experience. The SSN issues doesn't necessarily mean it is a EV related (8yr 100k) problem. I had an SSN issue a year and a half ago where my battery was replaced. However, the week before that diagnosis was made, the dealer diagnosed a relay that was not covered under the warranty. Cost me $100 for the $25 part and $75 for the labor. However, I don't believe for a minute that this was the real issue...but I think that was the best diagnosis they were able to make. This was before I got my OBDII Bluetooth module and Forscan running. No hard feelings...I give the dealer the benefit of the doubt. However, it does reinforce something that I have come to know...there are likely 100s of possible issues that lead to the same symptom...SSN. This is why I purchased the Forscan setup; so I don't have to rely on the dealer to tell me what's wrong.

In this case, I'd try a different dealer. When I had my issues, they didn't charge me to diagnose. Their position was that they would do the diagnosis and then seek payment from me or from Ford depending on the outcome. Sure, you have to trust they do the right thing, but I've been doing pretty good by my dealer...even with the $100 I paid for what I thought was an incorrect diagnosis. But, I think my dealer is much better than the one who wants to be paid for the diagnosis. Could be they don't know how to effectively diagnose the car and want to be paid for their time in case they are not efficient. If possible, find a dealer others have used for EV troubles. I do agree that Forescan is a good first step; but it isn't always a slam dunk.

Here are my Forscan experiences.
1) After I had the battery swap, the car was getting charging faults. Took me 2 days to notice that the temp of the on-board charger was getting too hot...using Forscan. Oringinally I was monitoring the charging current and noticing that it was starting out with a high current but eventually throttling back...eventually down to 1 to 2 AMPs before stopping and issuing a charge fault. I also noticed a funny sound which turned out to be one of the cooling pumps running dry. Eventually I noticed the high temp of the charger using Forescan and then noticed the coolant was very low. Dealer forgot to put coolant back in after swapping the battery. The charge circuit is in the same coolant loop. No cost to me; dealer fixed.

2) After about 1 year after the battery swap, I got SSN again. Got it quite a few times. Using Forscan I could see a communication fault between the TCU and the battery. There was another issue logged, but I don't remember what it was. After taking it to the dealer, they double checked the TSBs and sent me on my way. I got an SSN 2 times on the way home but I was able to get it home. Called the dealer and dropped it off the next day. Got a call mid day that it was ready. They went from connector to connector looking for an issue and found that the main battery connector at the rear passengerside wheel was not fully seated....likely another issue from the battery swap a year earlier. Forscan wasn't too helpful to me at the time, but in retrospect it made sense. No cost to me.

3) I got a yellow wrench thrown. I had this issue off and on well after the 3 year 30k warranty with respect to the cruise control. Cruise control would work, but if I tried to press the "resume" after disengaging with the brake or "cancel", I'd get a yellow wrench. I read the codes with Forscan and it indicated an issue with the steering wheel module. After a wrench was thrown a subsequent time, I noticed that the cruise control wasn't working at all. Later, with no yellow wrench, I noticed that the cruise control wasn't working at all. The error code, when searched online, indicated some issue with other steering wheel controls. Long story short, I suspected that the switch contacts were likely not conducting very well due to lack of use. I ended up just working the switches a bit aggressively and the problem went away. No more yellow wrenches and the Forscan errors are no longer generated....and cruise control is working. There is a good chance it is a coincidence, but at least I do see correlation with Forscan and its ability to help diagnose.

Anyway, for this case, find another dealer :)

Posts: 33
Joined: Mon Oct 22, 2018 2:23 pm

Re: Stop Safely Now Warning

Tue Jul 09, 2019 1:04 pm

I'm resurrecting this thread to report another SSN on my 2012 FFE. DTC code is P0A0A. This issue has been going on for 2 months now. Dealer has already replaced the harness, the PCM. Car always shut down coming to a stop as I remember. It happens very random so I don't know. The good thing is that this car is still under the extended warranty. The bad thing is that I have taken it into the shop so many times that I rarely drive it now.

Posts: 33
Joined: Mon Oct 22, 2018 2:23 pm

Re: Stop Safely Now Warning

Fri Jul 19, 2019 8:47 am

Has anyone had this issue with their cars? I believe that the SSN for my car will come on if I hit the accelerating pedal and release it too many times in a short interval. I have a feeling that the voltage fluctuation causes the interlock circuit to lock up. Anyone got any idea? Thanks.

Posts: 14
Joined: Thu Feb 21, 2019 11:46 pm

Re: Stop Safely Now Warning

Fri Jul 19, 2019 10:55 pm

I just did a quick google search on P0A0A. So generically, when there is an HVIL failure, this code is set.
HVIL is High Voltage Interlock Loop.
I made a post a couple of weeks ago about a poorly connected high voltage connector in my 2017. In that, I talked about 2-stage high voltage connectors.
Well, for the more important high voltage connectors, the second stage has an additional set of contacts, that sense when the connector is connected or disconnected.
This separate set of wires that do not carry high voltage, but run along the with the high voltage cables, form a loop through out the vehicle. The Wiring diagram shows this best.
Anyway, whenever a high voltage connector is disconnected, the loop opens up. This open is sensed, and the high voltage system shuts down.
So imagine that you have a crummy connection for the HVIL. The car will think that a connector is becoming loose, and will shut down the high voltage as a safety precaution.
I will describe the HVIL loop as I see it in the wiring diagram.

(sorry, drop box rotates the image)

The first loop "starts" in the PCM powertrain control module. Connector C175B pin 59
It then goes to the BJB battery junction box. Connector C1035C pin 5
It then goes to the GFM2 generic function module 2. Connector C1838A pin 9
It then loops through GFM2 connector C1838C out pin 3 and in pin 4
It then loops through GFM2 connector C1838D out pin 3 and in pin 4
It then loops through GFM2 connector C1838E out pin 3 and in pin 4
It then leaves the GFM2 connector C1838A pin 7
It then goes to the BJB connector C1035C pin 13
it then goes to the TCM transmission control module. Connect C1822A pin 13
It then loops through TCM connector C1822B out pin 4 and in pin 3
It then leaves the TCM connector C1822G pin 1
It then goes to the DCDC DC to DC converter control module. Connector C1457A pin 4, where it "ends".
The second loop "starts" in the DCDC connector C1457A pin 3.
It then goes to the TCM connector C1822G pin 2
It then loops through TCM connector C1822E out pin 1 and in pin 2
It then loops through TCM connector C1822C out pin 1 and in pin 2
It then leaves the TCM connector C1822A pin 14
And finally goes to the PCM connector C175B pin 55, where it "ends"

So by looking at this diagram, it appears that if there is a break in the HVIL, it will either be reported by the PCM or the DCDC.
It also appears that there are 12 connectors where as HVIL is sensed. This is for a 2017, so for a 2016 and earlier, it would be fewer connectors.
The connectors are:
C175B - 12v logic connector
C1035C- 12V logic connector
C1838A -

Posts: 51
Joined: Fri Nov 02, 2018 2:14 pm
Location: Belarus, Minsk
Contact: Website

Re: Stop Safely Now Warning

Sat Jul 20, 2019 1:33 am

On my FFE, I soldered a HVIL control circuit. Near PCM)
I use translator. Sorry for the mistakes.

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