Help please. Dashboard LCD's not switching off

I am hoping there is someone out there who can point me in the right direction with my dash LCD problem (digital speedometer, clock and odometer) The problem is they stay illuminated when the vehicle is locked and armed, thus slowly draining the battery. If the ignition key is removed, the LCD's shut off in just under 4 minutes (like they're supposed to), but as soon as I lock the car the LCD's momentarily shut down, and then come back on again either immediately or after 5 - 15 minutes. There are many threads covering similar dashboard issues, but nothing relating to my problem. I've had some diagnostics run on the car and two error codes were found (but no indication of when they occurred. My car is a 2004 model and I've owned it trouble free for 10 years, so I'm thinking the codes are old) Error codes 54 and 59. Searches on these codes indicate central locking issues, and the threads referred to earlier point towards door locks, ignition and light switches, but all of these modules are working fine, i.e. windows drop on opening, interior lights come on etc. Everything is working fine except these darned LCD's when the central locking is armed. Please has anybody experienced this fault, and what was the remedy?

I've not experienced it myself, so don't have an answer for you....but it sounds like the car thinks the door is open, or similar. You say the modules are fine, how have you tested these?

Hi PHS, thanks for the reply to my post. I agree with you, something in the car probably thinks the drivers door is open. From memory, opening the passenger door does not illuminate the dash LCD's The micro-switches in the door locking modules appear to be functioning correctly; unlock doors with remote, interior lights illuminate, so door unlocked switch OK. Lift exterior door handle, and window drops, and stays dropped, so handle and door open switches OK (if the door open switch is bad the window goes back up when you release the door handle) Closing the door raises the window to closed position, so door closed circuit is good (I think it's the same switch as door open) and central locking arms normally with no beeps, so the alarm module believes the door is closed and locked. nxi20 on PistonHeads is suggesting a faulty ignition switch, and this has been suggested by quite a few contributors on forums worldwide as well. It's not an expensive fix, so I might give it a try

Do the interior lights come on too, when it all comes back on? If not, that would rule out to my mind anything to do with unlocking or opening the door and would as you say point to the ignition switch, given that its a known 996 weak point.

Hi Robert, thanks for your reply - no, only the LCD's are energized

Ive only seen it once .. a car had been reverse jump started .. among several other defective items the dash wouldn,t go to sleep .. In that instance it was a faulty instrument cluster but at £2500 it was a hell of an expensive fault , i had a few sleepless nights after diagnoseing that i can tell you ... something called the gateway was stopping the car from going into sleep mode ... 996 and its inbuilt to the cluster .. 997 and its an external unit . Ignition lock is the first one to rule out .. so unplug it and lock the car .. youll soon know if its that or not . Check under the pasenger seat .. have a look as well .. no water there or drink bottles that might be leaking on the alarm control unit ? If none of that i think a garage is in order , get a 1 hour diag done .. basically they spend an hour and see what they can find .. after that any further investigation has to be authorised by you .

Thank you deMort - I've seen many of your posts, you seem to be the Wikipedia of Porsche!. Mercifully it's not raining so I'll get the car outside, disconnect the ignition switch, and see what happens. I'm wondering if I upset the system when I disconnected the battery a couple of months ago to repair the alternator. If if it's not the ignition switch, I'll also disconnect the battery and reconnect again using the correct procedure

Similar issue with mine last year and it was a faulty ignition switch

Dear All. Disconnecting the ignition switch didn't resolve the issue, neither did disconnecting the battery. I'll replace the ignition switch, as it's only £25, as there are just so many forum contributors in the Porsche community who have found that replacing the switch resolved their problems. I'll report back either way

I had a problem with lots of warning lights on mine, 9E took the instrument panel out, reset the computer and replaced it. All has been well since. They mentioned that a new panel is £2.5k but there is a firm in Yorkshire repairing and guaranteeing them for £150 if you need one.

Hi Maldren, do you happen to know the name of the company. I've searched the internet, but cannot find anyone doing Porsche instrument repairs in Yorkshire

Sorry I don't but Ken at 9E does and he'll probably help.

These lot were on Wheeler Dealer's: http://www.clusterrepairsuk.co.uk/about :thumb:

Hi, thanks to everyone who has responded to my post. OK, update,,, Ignition switch change did not solve the problem. The only circuit with a fault associated with the dash LCD's (OBC) is the OBC switch on the steering column which has has no function in the upward vertical plane. As actuating this switch (along with many others) energizes the dash LCD's, could a no signal (normally open/normally closed, I've no idea!!) cause the dash LCD's to remain on when the car is locked? Right now I am pulling fuse B1 to isolate the instrument cluster every night. Please let me know

I don't know but I believe you can unbolt and unplug the OBC stalk from the rest of the stalks. Just take the steering wheel off (disconnect battery for a while first so the airbag doesn't go off, and don't connect it back until the airbag is reconnected). Worth a go?