Check battery first

[Pondy]

Happy new year everyone!
I have read many, many threads on here about batteries being the root cause of all sorts of issues on the E89, so I thought I would share how important it is to check the charge of your battery before any other (and potentially expensive) avenues are pursued.
Today I drove my E92 (same electronics as all E89s and same N54 engine as the 35 and 35s) around the corner to pick up beer (it is new year's eve).
When I started the car and moved off in Sainsbury's car park the dashboard lit up with multiple failure/ warnings. These being: TPMS failure, DSC failure and ABS failure. I drove home with all the above showing on the Idrive and dashboard display.

First thing I did was check the tyre pressures; all OK. Second thing was to try and reset the TPMS; no joy it said it couldn't read tyre pressures and take it to a BMW dealer asap. The DSC and ABS warnings said there was a malfunction and ditto with the dealer visit.

So I googled the issue and most answers were either wheel sensor or hydro unit failure.

I thought I would try putting the battery on charge with my cTek charger, as it couldn't hurt. It took only 4 hours to fully charge. So I thought "it's not going to be the battery".

It was! Started the car, drove around the corner, all lights went out and the TPMS reset first time.

If I hadn't known the fussiness of BMW battery charge I would have booked it in for a diagnosis at the very least.

Lesson learned re the battery. Hope this helps some others

 

[flybobbie]

Thanks to car videos of dodgy battery connections, fixed an aeroplane.
Seemed like the battery was knackered again, couple of cranks, seemed like battery flat.
With maintenance we looked at the wiring diagram.
I did notice in past loose wires from battery box to a earth stud. We removed, stood had shoulder on which the nut tightened to, but not the eyelets of the earth cables.
Few washers and anti shake washer, all honky dory.
Starts like a goodun.
So always check you have good positive and body earths.
Especially on 45 year old aeroplanes.

 

[Mr Tidy]

Good advice there.

My 2nd E86 threw up an amber EML for post-cat O2 sensors on both banks. Got them cleared by my Indy then a couple of months later the amber EML came back so I booked it in again.

The 10 year old battery died while the Indy was running diagnostics.

New battery, codes cleared, sorted.

But I didn't learn. :lol:

The battery on my current one died in March. I got it started using a jumper pack, but then got the trifecta of ABS, DSC and TPMS.

Fitted the new battery but they didn't go out until someone with diagnostics cleared them.

 

[B21]

How old is the battery?

 

[Pondy]

How old is the battery?

Don't know Peter, I can't find anything on it apart from the amperages. It's a Yuasa so is not original.

 

[B21]

How old is the battery?

Don't know Peter, I can't find anything on it apart from the amperages. It's a Yuasa so is not original.

Maybe the battery is on its way out? If the car has been a garage queen it doesn't help..batteries that appear dead (or give the symptoms) and charge quickly are often short of capacity..FWIW..

 

[Pondy]

Maybe the battery is on its way out? If the car has been a garage queen it doesn't help..batteries that appear dead (or give the symptoms) and charge quickly are often short of capacity..FWIW..

The battery wasn't dead. The whole point of the thread was that it doesn't take much discharge for BMWs to throw a wobbly.
I have had intermittent bulb faults showing too when they are all fine. I've got a feeling this is battery-related.

 

[B21]

Maybe the battery is on its way out? If the car has been a garage queen it doesn't help..batteries that appear dead (or give the symptoms) and charge quickly are often short of capacity..FWIW..

The battery wasn't dead. The whole point of the thread was that it doesn't take much discharge for BMWs to throw a wobbly.
I have had intermittent bulb faults showing too when they are all fine. I've got a feeling this is battery-related.

If its the same charging logic as on the E89 /E90 which I assume it is then..

The battery is never fully charged by the chargimg circuit..it leaves quite a bit of capacity for the regenerative charging

As the battery ages then its capacity declines

Also if the Yuasa battery wasn't registered then it can throw things.

My 20i and XC70 both started showing signs like switching the radio off after a short period of time.

It takes about 6 weeks of inactvity for a healthy battery to start throwing those issues at least.

Again FWIW

 

[Pondy]

Thanks Peter. I will keep it charged and keep an eye on it. I'd rather change the battery than a hydro-unit; so it's not the end of the world.