I'm hoping someone can help with this issue. 

I have a 2019 ford focus 1.5 eco blue. My start stop system works fine no issue. I first got the car in January and my auto hold and hill start were intermittent they would work but I noticed that on a hill it would stop working. Suddenly one day it stopped working all together and hasn't worked in months. 

I believe the button is working as if I don't have my seat belt fastened and the door open, I push the button and a message that this can only operate once the door is closed and seat belt fastened appears. 

But anytime the door is shut my seat belt is on "Hill start assist not available" "auto hold malfunction" 

The only two consistent codes that appear to keep reappearing are these. 

 

U0404 - invalid data recieved from Gear Shift Module A

Module - antilock breaking system. 

&

P166B - drivers door status correlation 

Module: Gear Shift Module 

I have attached photos of this please ignore the other codes as these are not consistent and one is linked to my disconnecting the battery cable earlier. 

What is bothering me is that both of these codes are linking to the Gear shift module and the Abs which operates the auto hold is featured. 

If anyone has any thoughts I'd be really grateful as it's got me baffled 

 

This may, or not explain (do let us know)...

The door switch looks like the culprit to me (test with live data to make sure?) as it is intimately involved with HLA especially auto?

2011 S-MAX handbook:

So i have ran a live data test on the system. 

There are a couple of normal event's and likewise a couple of strange ones. 

DR_AJAR_HWI - No - so we know the door isnt seen as ajar

DVDR_DR_COUNT - 0 This figure didnt change at any point

LK_DOOR_LK_0 - This changed to Lock door active every time i pushed the lock button before returning immediately to no control active.

What I have noticed is 

DR_UNLCK_HWI - This tells me there is a door unlocked. This didnt change no matter how many times i pushed the lock and unlock button and the value remained Yes. 

but the strangest one is

SS_INHIB_G1_17 - This tells me that the start stop function is inhibited because the drivers door is open and the value remained at Yes. Now I havent really had a problem with my start stop it's the auto hold and hill start that dont work, but what I am aware of is that my start stop doesnt work straight away. Sometimes this takes ten minutes of driving if not longer before this function starts working but i've never had an error. What I am now wondering however, is if this system is detecting the driver's door is open even though it isnt is this whats causing the malfunction in auto hold and hill start because these systems are malfunctioning straight away and at that point will remain out of action. 

I could just be speculating here but thoughts would be appreciated. 

Liam, just a reminder re Stop/Start - its working depends on various things including

Battery SOC (state of Charge), Low water temperature of engine, Ambient temperature 

Yes this was another thing. 

I did notice yesterday that my car appeared to have a soc of 73% on forscans analysis but this confused me as the car had a voltage on multimeter of 12.6v (after 45 minutes of driving and being shut off) I have noticed that before driving the soc seemed to be 12.5 and on my initial check as low as 12.35 but I've not had any issues with starting and the car is driven daily. 

Just for information, there are between 110 and 114 conditions (depends on model options) that have to be correct on a Focus Mk4 before the Stop/Start system will be activated. The major point that seems to be over looked by many drivers is that the system is designed to operate when the car has determined the conditions to be correct and not when the driver thinks it should.

Regarding the possible problems with the with the detection of the drivers door lock status. Have you run the same tests on the front passenger door to see if the results are the same ?

If the results are different to that of the drivers door lock then that would confirm a problem. What is confusing is that the micro switch inside of the door latch is used by many circuits to detect the status of the door. I'm assuming that: (a) the drivers door locks as normal (b) there is no door ajar warning light (c) the courtesy lights operate correctly (d) the alarm system is operating. This could well be a software glitch with the body control module. Using FORScan you could reboot the BCM to see if things change.

I would say battery voltage is low.

Fully charge the battery and increase the charge limit in the BMS to 95% 

If you are still getting issues I would be tempted to have all the software updated as there were a lot of glitches in early MK4s

Thank you for the suggestion's, I will run the same tests on the passenger side door and see if this makes any difference however, some of the tests are only available for the drivers door and the fault code did link to the drivers side door correlation so that made me suspect this. 

I have previously increased the charge limit on the BMS as this was suggested months ago when I first began trying to identify the problem but this doesnt seem to have resolved matters but I am going to be getting my hands on a trickle charger later today and identifying if after use this makes any difference. I am unsure at this stage but it never hurts to try and a battery charger is always useful to have around so thank you for the suggestion. 

In regard to unofix's comment about the systems operation yes on all counts no errors with locking, courtesy lighting, alarm system or warning lights and all of these systems function as they should. 

Only one slight thing that I am wondering is I saw a post in recent months about the transmission not in park warning appearing on the dash. I cannot find the post now but it indicated this can occur if the drivers door is open, and I do get this message daily when slowing down, or when first beginning to drive the car when the car is moving I have always thought this was rediculous as obviously it's not in park I'm driving but unsure if that could be related. 

I will report back later with any findings

Thank you

25 minutes ago, FordWL said:

I have previously increased the charge limit on the BMS as this was suggested months ago when I first began trying to identify the problem but this doesnt seem to have resolved matters but I am going to be getting my hands on a trickle charger later today and identifying if after use this makes any difference. I am unsure at this stage but it never hurts to try and a battery charger is always useful to have around so thank you for the suggestion. 

You probably need a new battery then

 

25 minutes ago, FordWL said:

Only one slight thing that I am wondering is I saw a post in recent months about the transmission not in park warning appearing on the dash. I cannot find the post now but it indicated this can occur if the drivers door is open, and I do get this message daily when slowing down, or when first beginning to drive the car when the car is moving I have always thought this was rediculous as obviously it's not in park I'm driving but unsure if that could be related. 

Try updating all the software first

another owner the software is good, it must be something else...

 

all cars are thrown together with barely functioning software that's so buggy it defies belief - but somehow between the user and the people maintaining it they know best - even if faced with 5 separate TIPS documents mentioning issues that can only be resolved with an update

6 hours ago, FordWL said:

this can occur if the drivers door is open, and I do get this message daily when slowing down, or when first beginning to drive the car when the car is moving I have always thought this was rediculous as obviously it's not in park I

This is kind of confirming that either you have an intermittent fault with the door latch circuit, which could just be a faulty microswitch in the latch, or, you have a software fault. The lack of other problems is kind of pointing to a software issue, this could be with the BCM, PCM,TCM (now that I know you have an automatic).

16 hours ago, unofix said:

this could be with the BCM, PCM,TCM (now that I know you have an automatic).

And GSM and DZMs definitely

I'd update everything possible on an early MK4

Sorry for the late response all it took me a few days to get to the bottom of this. Turns out most of my modules have had updates done already so that was a no go. 

I charged the battery although I wasn't sure if this would be the problem I have been wondering about the charge state for awhile but again that didn't sort it. 

Finally I obtained a second hand door lock actuator mechanism and bracket from a local breaker. After a battle getting the old one removed I installed the new one, connected it all up and boom malfunctions are gone auto hold and hill start assist are working again and the transmission not in park message has vanished. Turns out on these actuators there is a second microswitch for sending signals to the GSM which wasn't working correctly while the other switch which controls the other functions was. 

Sorry it took so long to update you but it took me two days to figure out how to get the window glass out of the way to work on it because on one side of the window the rail clip holding the glass was missing and someone had installed a clamp mechanism as a replacement 🙄

But finally sorted!! This problem has been bothering me for months thank you all for the advice! 

 

 

 

 

2 minutes ago, FordWL said:

finally sorted!! This problem

Thanks for coming back and updating the thread. That's very useful information to know and I'm sure it will be of help to others in the future 👍