L322 L322 2008 TDV8 Transmission fault, High Voltage

My tdv8 keeps giving me transmission fault limited gears.
Accompanied by HDC and suspension errors.
I have connectors to check and some loom stuff.
But I noticed today 15v showing in gap IID.
Could my alternator be failing and voltage too high causing faults like voltage too low dose.

I cleared codes and started it up this morning gap iid said 14.7 volts volt meter across battery said same with engine running.

got a mile up the road and the below faults came up, voltage was 14.7 at the time.

I tested battery with it disconected from car 12.4 volts, my battery charger reports battery as low so it is on charge now.

I think i am looking at a new battery this one is about a year old and then perhaps an alternator. I prefer that to new gearbox or transfer box.

Get the battery fully charged and test the testing voltage, it should sit at 12.7.. low volts can cause spurious errors
15 sounds high check it with a meter directly

This time of year my D3 will run 15.1 volts pretty much all the time.
I mainly do short commutes, but even when I go further afield it is rare for it to drop under 14.5 volts.

15 volts is quite likely correct if the battery's state of charge is low. As the battery's state of charge rises, the voltage will drop as low as 13.8 eventually.

Didn't know the L322 went that high, it's all a learning curve!!

kermit_rr said:

Didn't know the L322 went that high, it's all a learning curve!!

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Even my P38 with a mobiltron regulator will go that high if the battery is very low. Normally just after starting from cold it hits 14.8 briefly, but having just come off the solar charger the battery only needs the starting drain replaced.

A failed or failing battery will often cause the voltage to remain high for much longer that necessary, simply because the battery isn't able to absorb the excess energy.

Nodge68 said:

A failed or failing battery will often cause the voltage to remain high for much longer that necessary, simply because the battery isn't able to absorb the excess energy.

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A bad earth from engine to chassis can also cause high voltage