Scenic II - battery drain, key card not recognised

mikeschhorn · Jul 30, 2012

Hi all,

I'm desperate for help for my wife's 2005 grand scenic II, 1.6 petrol.

Symptoms:
constant drain of ~ 1.5 A on the battery with the car "at rest", which flattens the battery quite quickly . This is coincidental with the key card not being recognised by the ECU; when fully charged, the card gets recognised and the car starts ok, but even the slightest drop in battery voltage results in intermittent card recognition and eventually in total failure to start.
The car had recently the dashboard and the engine compartment fuse board replaced. It also shows a “Check parking brake” message on the dashboard after the pads and one of parking brake callipers had been replaced. The electronic parking brake works absolutely fine otherwise.
There is no other apparent failure in any other system (writing this, I will check again tonight).

I’ve replaced the battery with a slightly bigger one and changed the key card reader, which obviously didn’t make any difference.
I removed all accessible fuses in the glove compartment and under the passenger seat, one by one to check by process of elimination which circuit would cause the battery drain. With the majority of fuses, when removed, the load on the battery even increased to ~ 4.5A. Removing the fuse for the electronic barking brake (which according to a French service manual is one of the fuses under the passenger seat) didn’t make any difference.
Disconnecting the alternator also didn’t change the load on the battery. I also tried to check the newly installed engine compartment fuse board, but only partly succeeded because of its inaccessibility. I have not checked the solenoid on the starter motor yet, but I doubt it’s that.

1st: Am I right in assuming that the battery drain and resulting drop in voltage causes the ECU to NOT recognise the key card? Unfortunately I don’t have a second card to eliminate a possible intermittent card failure. Obviously, a key card failure wouldn’t explain the drain on the battery.
2nd: What could cause the battery drain? I’m still suspicious of the coincidental parking brake fault but I would otherwise guess its faulty earth somewhere.

I’m pretty handy with the spanners but have up to now refused to touch the car. Our local mechanic is quite good and trustworthy but has honestly admitted of being out of his depth with car electronics. Our experience with the dealers has been atrocious, so it’s my job now.
Any help would be greatly appreciated.

Tom

mikeschhorn · Jul 30, 2012

Hi all,

just read my text again:

electronic barking brake

how fitting, lol :d

Read in an other thread that the dephaser solenoid has been known to cause battery drain.
However, there is no noticeable rattle and the car has a good pull.

Any ideas?

madnoel10 · Jul 30, 2012

The dephaser solenoid is a known problem - have you done a voltage drain test with it disconnected.

mikeschhorn · Jul 30, 2012

Thanks,
will try and post result.

mikeschhorn · Jul 31, 2012

Same battery drain with dephaser solenoid disconnected

Rentech · Jul 31, 2012

Unplug the radio and see if that helps, also under the passenger carpet under the seat is 2 big multiplugs you have to take the seat out, water collects here and shorts or rots out the connectors. Check when you lock the car with all the doors and bonnet shut that all the dash lights go out except immobiliser light. Also if it is fitted with second fit alarm this unit can draw amps when faulty.

MickR · Jul 31, 2012

For what its worth I had battery drain problems when my camshaft position sensor was playing up. Some mornings the battery would be flat and I had to use the key to get into the car. Since a new sensor was fitted 2 years ago I have not had a similar problem.

mikeschhorn · Aug 16, 2012

Update after two weeks:

After driving the car with always carrying a fully charged battery in the boot and disconnecting the battery every time the car was parked, I finally decided to have the key card checked to make sure that the reluctance to recognise the card was not due to a faulty card (don't have a second card to check). What convinced me in the end was that the card rattled when shaken.
Sent the card away (ebay service £20, turn around 1 week) and presto the "card not recognised" message on the dashboard has gone. Great job, can only recommend it.

Car still won't start though.
ECU powers up, checks lights and oil level but doesn't turn engine. Fully charged battery, no click on the starter solenoid.
Same symptoms as a few month ago. Changing the engine fuse-box cured that.

I would find it hard to believe that it's the fuse box again. I'm aware that they are prone to take in water (had a lot of rain recently since the car has been standing in the yard). Am I right to believe that it could be the main loom leading to the fusebox? How can I check that (I've got access to a FR704 CAN bus OBD scanner)?

Any ideas anyone?

Rentech · Aug 16, 2012

very hard to tell when it is not plugged in to clip, the loom that runs across the battery spilt the tape there and check for rotton wires there and check and you can check whether there is feed to the starter fuse. If the system is working ok the immob light should come on and go out after you have put the card in.

mikeschhorn · Sep 6, 2012

Fixed

Looks like it was several faults coming together:

The key card was faulty. It probably had a loose solder connection of a board component - that initially caused the intermittent "card not recognised". When the component came of the board the cat totally failed to start. This would explain the why the car initially could be started by squeezing the card case.

With the key fixed but the car still failed to start we found a loose connection on the starter motor.
With that fixed and the electronic parking brake fault cleared from the ECU the battery drain also stopped.

What finally caused the battery drain I still don't know. :crazy:

Scenic II - battery drain, key card not recognised

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