Troubleshooting ABS U0401:68-48

[Nondisclosed]

2014 2.2l Transit Custom
Duratorq-Turbo Diesel common Rail Injection
2 x battery under driver seat

Thanks for taking the time to read this and help me out.

I'll give a brief recent history of the van, though I have had a bit done to it over the past couple of years, including a new PCM fitted by Ford. Battled with the dreaded DPF for a while as it's not my main vehicle so don't get to drive it as much as I'd like. It had a new turbo fitted a year and a bit back. Been a steady dance with DTCs but starting to think I'm getting everything ironed out.... for now For the past few months it hadn't had much use unfortunately and unbeknownst to me I wasn't doing it any favours by idling it outside the house to "keep it ticking over". Once I stopped that, after a mechanics advice , I quickly realised one of two batteries was on it's last legs so I replaced it a couple of weeks back. Recently I was fighting against turbo DTC's but have been told it'll be due to back pressure from the DPF. Fingers crossed, I've been out in it today and it's running fine and the turbo & DPF codes haven't returned. However, at some point it developed
U0401:68-48 on the ABS system and I'm getting the traction control warning light and service engine light. I have cleared the code multiple times today and it returns, some times instantly or other times not long after clearing it and driving. I've performed OBD tests to the ABS system and that normally gets rid of it, but then it returns.

I have also just noticed in a past saved report U0073:88-28 control module communication bus A off & U0074:882C Control Module communication bus B off.

So my question to you fine people is, what have a done wrong? What troubleshooting can I do to find out what the culprit is?

Again, thank you for any time you can spare me solving this.

[metalworker0]

Don't know what you are using to see the codes

if you were using forscan ..it would give you "real time data" ..from which you would be able to see all 4 wheel sensors and their signals .. so if wheel sensor fault you would see it, and the relevant wheel it refers to, in the graphs it would draw whilst driving.

i'm only as good as anyone else here, no one has a head full of codes - ...i just put the codes into google and read what it says.

of which part of the answer is this list of possible causes:

1.Communication Problems: Issues with the Controller Area Network (CAN) bus, which allows modules to communicate, or wiring harness problems.

2. Faulty Modules: A problem with either the ECM or PCM itself.

3. Low Voltage: A low voltage issue could be interfering with the communication.

4.Other Codes: The U0401 code could be triggered by other underlying issues, such as a problem with a sensor or a blown fuse.

of which i would check out number 4 first ..as it the easiest to rectify.

all the best.mark

[knobby1]

Uxxxx fault codes are "usually" Can-Bus communication issues....I'd be checking all earths and wiring for issues first. ABS modules rarely fail.

Lord Knobrot

[Nondisclosed]

Don't know what you are using to see the codes

if you were using forscan ..it would give you "real time data" ..from which you would be able to see all 4 wheel sensors and their signals .. so if wheel sensor fault you would see it, and the relevant wheel it refers to, in the graphs it would draw whilst driving.

i'm only as good as anyone else here, no one has a head full of codes - ...i just put the codes into google and read what it says.

of which part of the answer is this list of possible causes:

1.Communication Problems: Issues with the Controller Area Network (CAN) bus, which allows modules to communicate, or wiring harness problems.

2. Faulty Modules: A problem with either the ECM or PCM itself.

3. Low Voltage: A low voltage issue could be interfering with the communication.

4.Other Codes: The U0401 code could be triggered by other underlying issues, such as a problem with a sensor or a blown fuse.

of which i would check out number 4 first ..as it the easiest to rectify.

all the best.mark

Thanks for the reply Mark, slightly ashamed to say I'm not using Forscan yet... all I have to hand is a Topscan, I'll have to see if it has that level of data, seems fairly comprehensive but I understand its not going to be ideal.

[Nondisclosed]

Uxxxx fault codes are "usually" Can-Bus communication issues....I'd be checking all earths and wiring for issues first. ABS modules rarely fail.

Lord Knobrot

Lord Knobrot, thank you Sir!

Could there be any correlation to the battery issue? It was dying while it was parked up and to get in I would have to recharge the battery.

More direct to your point, could you advise on an order of checks for me to perform?

[knobby1]

Lord Knobrot, thank you Sir!

Could there be any correlation to the battery issue? It was dying while it was parked up and to get in I would have to recharge the battery.

More direct to your point, could you advise on an order of checks for me to perform?

As mentioned, ABS modules rarely fail, if your front battery requires charging to get into the van, it's probably dead or dying...the front battery does the majority of the work and usually fails first, when the van isn't running it keeps the van alive, it supplies the alarm, clock, interior lights, central locking etc...and will slowly disharge over time if not used frequently. The rear battery is just connected for starting and running but is not connected when shut down.

Get both batteries properly load tested, not just voltage, some batteries can show decent voltage until loaded, then they fail miserably.

Lord Knobrot

[Nondisclosed]

Done that, sorry didn't make it clear in my original post. Before I replaced the dead battery, I maybe charged it 3-4 timed. Just wondering somewhere along this process something could of happened?

[Nondisclosed]

Ok, so I've moved to Forscan and I have now found another code coming up on the ABS U0422:68-08. Does this at all narrow it down?

[metalworker0]

Unless im wrong ./.has nothing to do with the ABS system or has it ????

this video gives the Fuel system in the tank, there is fault detailing at end of the video, where to focus , what to look closely at.

https://www.youtube.com/watch?v=SsMnXHUdFAQ

google AI says

U0422-68 in Ford models, such as the Transit, can sometimes point to issues with the fuel tank pressure sensor or related components.

other places point to ABS

[Nondisclosed]

Unless im wrong ./.has nothing to do with the ABS system or has it ????

this video gives the Fuel system in the tank, there is fault detailing at end of the video, where to focus , what to look closely at.

https://www.youtube.com/watch?v=SsMnXHUdFAQ

google AI says

U0422-68 in Ford models, such as the Transit, can sometimes point to issues with the fuel tank pressure sensor or related components.

other places point to ABS

Q
OK I can go that, thanks. It came up on the ABS dtcs so assumed it was associated with my original U0401:68-48 with them both coming up as ABS faults. I am also having issues with the DPF auto regennin, had to static regen it today. Was told having DTCS can stop it