DB9 "Gear display position not available" error (AGAIN)

[toptiger]

I though I'd start a new thread and hopefully someone can point me in the right direction. Went to fill with petrol (and yes, did fill with petrol). Afterwards, car would not start. Very short pulse from starter motor then all 4 P, N, D, R lights on (2008 DB9 touchtronic with ZF auto gearbox). Error "Gear display pos not avail". Called for recovery who checked every fuse - all ok. Also tried to start car from jump leads to no avail. Checked other threads but no clear resolution to the issue. One such thread pointed to Relay 4 in the Boot Fuse box. This also looks ok and I checked it with a multimeter. Some threads point to the battery but if that was the case why would the car not start when hooked to the AA van (direct to the DB9 battery not the jump terminal under the bonnet. Really hope someone can help.

[paulrog1]

Sounds like either your battery is maybe on it's way out or the tracker giving out CAN-BUS errors.

I would goto Bamford Rose to disconnect your tracker and then replace your battery, make sure you charge the new one up for around 24 hours with a battery conditioner after replacement as the new one don't have a full charge from the shop.

Did you press the battery reset button, maybe that prevented the car from starting, it's not on all cars but I believe it's near the battery.

Definitely do this above before going deep into the gearbox electrics.

Edited by paulrog1 on Tuesday 11th May 13:46

[toptiger]

Thanks. I have a new battery arriving shortly so hope that fixes the issue. We shall see. One would think that back in 2008 ECU software would be advanced enough to detect that the battery is at fault and not flag a gearbox issue instead! I will keep the post going until I find a solution. I'll get the tracker disconnected when I can get the car started and back on the road.

[toptiger]

New battery fitted, same fault. Finally traced the fault to the battery disconnect switch in the boot. Just removed the plug from the back of the switch and eureka, car now starts.

[4Q]

Glad you got it sorted and thanks for coming back with the solution.