2021 VW crafter intermittent charge fault on dash , codes U105200 U140600, battery stays charged
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- Опубліковано 22 сер 2024
- 2021 VW CRAFTER diesel
Could this cause a dpf fault 🤔🤔🤔🤔🤔🤔🤔🤔🤔
HERE IS SOME GREAT INFO I FOUND
Smart charge alternators have been around for a number of years but the complexity of their design has evolved considerably, according to starter motor and alternator specialist Autoelectro.
Smart charge alternators can usually be identified from their regulator plug type (LIN, BSS and COM)
To check if a vehicle has a smart charge visit the Autoelectro website that contains information on the plug regulator and the pin functions for each vehicle application.
An Autoelectro spokesperson said: “In a non smart charge alternator, when the engine is running, the a constant voltage of between 13.8-14.4 volts is produced, depending on the battery charge level and engine speed.
“The higher the output the greater the mechanical load upon the engine, causing the vehicle to consume more fuel.
“Conversely after a cold crank start a smart charge alternator can work to maximum output capacity, and the ECU can instruct the alternator to send up to 18 volts to the battery.
Correct battery is essential
“For this reason it is essential that the correct type of battery is fitted to the vehicle.
“The incorrect battery may not stand up to the charge rate of a smart charge system and could easy overheat causing failure of the battery and may also cause damage the alternator and other electrical systems within the vehicle.”
Smart charge alternators are controlled externally by the ECU with information being sent between the two via the communication cable as a signal.
The output of these alternators can vary dependent on the information sent to the ECU from the various sensors, the state of charge of the battery, demands from the vehicles electronic parts and accessories such as heated screens/seats, infotainment systems etc.
The benefit of the smart charge system is it can output a lower voltage over a longer period thus reducing the drag upon the engine, this reduced drag leads to improved fuel efficiency.
How smart charge alternators work
The spokesperson said: “During acceleration the ECU can effectively turn off the alternator, and this means the vehicle has more power as the alternator bears no load on the engine, and on overrun the alternator can be allowed to overcharge as this does not affect vehicle performance.
“A battery accepts charge more efficiently when it is cold, for this reason a smart charge alternator will charge at a higher rate to maximise the charge performance and bring the battery back to optimal operating level.
“Once this level is obtained the ECU will reduce the alternator output to supply the vehicles demands.”
According to Autoelectro, the majority of smart charge alternators do not actuate the battery charge light itself - this is controlled by the ECU.
Related: Autoelectro invests in new test bench for latest starter and alternator technology
“The battery charge light can illuminate for various reasons and the vehicle should always be checked for underlying faults before condemning the alternator.
“An example of this is on the three-pin regulator Ford type Alternators fitted to Fiesta, Focus, Kuga and other models, such as Autoelectro part number AEK2815.
“Common faults can exist on the vehicle wiring loom, which is around 40cm long.
“It has been found that corrosion within the wiring loom can occur and will interfere with the communication between the alternator and the ECU, using the battery charge light to illuminate and possibly low or no output form the alternator.”
Oscilloscope diagnostics
When testing a smart charge alternator, the communication between the alternator and the ECU is in a wave pattern form that requires a suitable device to read such as an oscilloscope.
Conventional testing methods will not suffice, Autoelectro say.
“The signal from the ECU to the alternator should be a square wave pattern that will change with load request.
“If there is no change in the pattern this signifies no request from the ECU, and further investigation is now required on the vehicle.”
All Autoelectro smart charge alternators are tested to OEM specification on the very latest OEM end of line test benches
because you car has automatic stop/start and AGM battery your car automatically chooses when to charge the battery, so after you start the engine it may not charge the battery straight away, the charging system is disconnected giving more power at the wheels and fuel saving and reduced emissions , all of the electricity being used by the car is coming from the battery, the charging system waits until the car has unused energy available, say coasting down a hill or using the brakes its then able to charge the battery very fast with what would have been wasted energy this can save upto 10% of your fuel costs and have a big effect on your vehicle emissions it will also postpone charging until engine is at running temperature unless there is a risk of a depleted battery
Thank you sir it was only a gut feeling of watching the data and thinking out of the box
You certainly help me understand this system a lot more ,so it could be used for the dpf regeneration as well 🤔🤔🤔🤔
dont do static regen !!@@trevorchillery1019
That was a good one Trevor most would have condemned that Alternator. Got to say that I’ve gained some useful information thanks to yourself and johnfountain 8143🙏
Thank you sir if it help one person ,apart from me this time it’s worth doing 👍👍🤠
You have a request in the video about some parameters to start charging the battery, possibly something to do with temperature? Can you put that in a Comment with your post on DDTSB, I am guessing that not loads of members will also watch the video but will read your post and possibly give you an answer. cheers.
Has anybody changed this alternator? If the wrong part number was installed, it might not be speaking the same LIN header??
Original alternator was fitted sir but I’ve learned a lot more since I fixed the lin bus wire and I now have more questions
Same problem with my crafter, changed battery, alternator, found the same wire damages. But with all new staff it worries me that without load there is no charge on the battery, only when you put lights on and etc...
It’s a good learning curve sir but at least you can test it 👍👍👍🤠
@@trevorchillery1019 looks like working as supposed to, gives 12.5 on cold, then 13.1 on idle, when coasting 14.6, press gas - no charge as to limit emissions) . So confusing ) but as supposed to i guess)