High Rate of Battery Discharge Error

[Pjwmhere]

X5sport,

When you were talking about the transmission fluid change, you mentioned a kit, I have seen there is a ZF kit advertised on AUTODOC with the transmission fluid and the oil pan for less than £250, it says it’s suitable for this model. I’m going to get the garage to do it but wondered if worth buying one of these kits and just getting them to do the work?

[X5Sport]

If you were in the car and the sensor was showing then that sounds like the alarm one. It will only draw a tiny amount of current as part of the alarm system. There are also tilt sensors built into the stability and crash protection systems, neither of which can be completely disabled. If your alarm has gone faulty then it could be keeping the car ‘awake’

Hunting parasitic drains needs an accurate ammeter that can read down into mA and time. Every time you ‘wake’ the car you have to wait for it to shut down again in order to proceed. These cars should draw very little power in standby, 25mA according to the manual. Then it’s a case of pulling fuses. A BMW Dealership may have the right software for a full diagnostic, they certainly found one when I had a Road Angel connected to the upper USB port in the glovebox. You need a current clamp, or an ammeter with a ‘bridge’ that protect the meter from high current. My X6 draws more than 60A just with the ignition on.

These are the shutdown cycle steps:
Time Event Typical current values
0 ‐ 3 min Reaching the idle state 6 to 15 A depending on the equipment.
3 ‐ 8 min Vehicle sleeping 0.4 to 1.5 A depending on the consumer units that are switched on (e.g. map-reading light or glove box light).
8 ‐ 9 min FRM wakes up the vehicle: Consumer unit shutdown. 6 to 10 A depending on the equipment.
9 ‐ 30 min or 9 ‐ 60 min Vehicle sleeping 500 to 650 mA depending on the equipment.
30 or 60 min Shutdown of terminal 30 switched 25mA.

The proper way to check it needs ISTA (Integrated Systems Technical Application), part of the BMW Diagnostic Software Suite. You may have to bite the bullet and take it in for a full check.

[X5Sport]

X5sport,

When you were talking about the transmission fluid change, you mentioned a kit, I have seen there is a ZF kit advertised on AUTODOC with the transmission fluid and the oil pan for less than £250, it says it’s suitable for this model. I’m going to get the garage to do it but wondered if worth buying one of these kits and just getting them to do the work?

Sounds about right. Good price too. Mine was £1k but that included front/rear diffs and transfer box. Mine was done by a BMW Specialist in Bletchley (Milton Keynes). He charges about £100/hr, much less than BMW - assuming you can find a main dealer who would even do it. There’s a specific sequence and set temperature needed to change the transmission oil. It’s not difficult, but you need to be able to read the tx oil temp.

The transfer box drain and fill is a pain as you have to get a structural cross member out of the way and support the gearbox. The car was obviously designed to be built, not serviced!

[Pjwmhere]

Thanks for your very detailed clear explanation, you are a star

[IanP]

On my x6 the main engine relay latched in occasionally giving this battery discharge fault