U0146 fault

[Bogdoggirl]

I have a fault code of u0146 coming up on my T6 campervan. It appeared after starting the van after 4 days holiday where I'd accidently ran the battery down whilst running a fridge. I had it tested at kwikfit and they said the battery was fine, but was only 30% charged. I reset the alarm as I thought it was a low voltage fault on my battery but, I've driven the van a few times since and the fault appears once again on start up.
I can reset it and it stays off until I start it again.
I've tested the running voltage at the battery and I'm getting 14.6v.
Is this a common fault and has anyone got any thoughts on where I should look next?

 

[DXX]

It’s not good to run a fridge off the starter battery if you are not running the engine, many have a separate leisure battery or power bank for this purpose.
A lead / acid battery such as the starter battery has a minimum state of charge (SOC) of 50%, if it gets discharged below this it is going to be damaged.
Assuming that you drove from your holiday to kwikfit to test the battery I can’t figure out how you managed to start the van with what must have been less than 30% SOC?
By the way KwikFit would definitely not be my or many others preferred option for any maintenance or diagnostics.
Have you physically attached a battery charger and fully charged the battery?

 

[Bogdoggirl]

I had not adjusted the switches inside the van so the fridge had been draining the leisure battery and main battery . The van was sluggish to start but, it did (thankfully). We then drove for 2 hours home without changing the switches (fridge still on) and then went to KwikFit (as it’s very close to home) and they said the battery health was 100% but soc was 30%. We were advised to give the van a good run out but, I think we’ll attach a battery charger as you suggest

 

[DXX]

I had not adjusted the switches inside the van so the fridge had been draining the leisure battery and main battery . The van was sluggish to start but, it did (thankfully). We then drove for 2 hours home without changing the switches (fridge still on) and then went to KwikFit (as it’s very close to home) and they said the battery health was 100% but soc was 30%. We were advised to give the van a good run out but, I think we’ll attach a battery charger as you suggest

The van alternator will never fully charge the battery due to Bluemotion technology, charging occasionally with a separate charger or even better daily with solar extends the battery's life.

 

[Bogdoggirl]

The van alternator will never fully charge the battery due to Bluemotion technology, charging occasionally with a separate charger or even better daily with solar extends the battery's life.

We do have a solar panel on the roof

 

[mmi]

I have a fault code of u0146 coming up on my T6 campervan.

I've driven the van a few times since and the fault appears once again on start up.

How did you know there was initially a fault code? Any dash warning lights, or just daily routine check for fault codes?

 

[Bogdoggirl]

How did you know there was initially a fault code? Any dash warning lights, or just daily routine check for fault codes?

We got an amber engine management light on the dashboard. We later used our sons OBD reader and got the U0146 code

 

[mmi]

We got an amber engine management light on the dashboard.

Exactly which light - flashing coil or symbol of engine?

We later used our sons OBD reader and got the U0146 code

As U0146 is about CANbus communication issue, I would expect to see a fault code in the module which failed to communicate with engine.
Is the OBD reader just a generic reader (engine only)? I suspect the origin of the fault is communication with ABS.

 

[Bogdoggirl]

It was the symbol of an engine.
Yes, a generic reader (engine only)
Strangely enough, we changed a faulty ABS sensor a couple of weeks ago (just before this fault)

 

[Bogdoggirl]

 

[mmi]

Thanks.

It was the symbol of an engine.

Strange as that symbol should indicate only emission related fault. I have thought a communication issue wouldn't be a one.

Which engine you have. The code please, it's on a sticker under dash by steering column, or on a service booklet.

Anyways, would be helpful to get a full proper scan of the van to get better idea. Ideally a VCDS scan.

By the way, does the cruise control work?
Does the van have a swivel left front seat? Aftermarket?

 

[Bogdoggirl]

Sorry for the delay in responding. My husband has had the battery on charge all morning.
As far as we know, yes, the Cruise control does work although neither if us have actually used it. There us a double passenger seat which does rotate. The van is a conversion.
The engine is 2.0 TDI Diesel: CXGB

 

[mmi]

Strangely enough, we changed a faulty ABS sensor a couple of weeks ago (just before this fault)

Front or rear?

There us a double passenger seat which does rotate. The van is a conversion.

Rear ABS sensors are wired via a connector under left seat - hence the question.

As far as we know, yes, the Cruise control does work although neither if us have actually used it.

Asked because an issue in ABS circuitry would likely affect cruise control.

 

[Bogdoggirl]

We decided to purchase a TOPDON ArtiDiag600s which arrived today. It will probably save us a lot of money over time . We ran the diagnostics and discovered a couple of faults. One of these was an ABS issue on the rear left side (the one that we’ve recently changed). We’ve reset the alarm and everything has now cleared. My husband is going to take the van out for a decent run tomorrow and hopefully, all alarms will stay off