Thread: Losing All electrics after trying to insert GAP Tool

Originally Posted by John_D4

After reading this thread I’m feeling less like getting an iiD to be honest! The TD5 nanocom was plugged in all the time and I would turn it on as I started the car as a habit.

Best to wait until Gavin has resolved his problem as it may be entirely unrelated to the GAP tool. Nick

Originally Posted by John_D4

After reading this thread I’m feeling less like getting an iiD to be honest! The TD5 nanocom was plugged in all the time and I would turn it on as I started the car as a habit.

G'day John.
apart from Pippin's comment, I'm not sure that the Nanocom can give as much instrument mode information as the veritable plethora available with the GAP Tool. Really spoilt for choice with the GAP - alternatively, maybe consider a BBS IQ, which can be left in permanently? Have to admit, I'm not too keen on the IQ black background display with my old eyes, but would be worth talking to EricSDV6 if interested as he has one.

My gut feel is that its loose pins in the OBDII port (or not previously considered, potentially in the GAPTool?) that is shorting out and causing mayhem for me, but time will tell.

Originally Posted by gavinwibrow

My gut feel is that its loose pins in the OBDII port (or not previously considered, potentially in the GAPTool?) that is shorting out and causing mayhem for me, but time will tell.

I think you are on the money here - the comment from GAP that the earth pins MUST engage first combined with my own experience of using the wrong lead on my Nanocom confirms that bad pin connections and shorting out wrong circuits does create mayhem.

Originally Posted by gavinwibrow

G'day John.
apart from Pippin's comment, I'm not sure that the Nanocom can give as much instrument mode information as the veritable plethora available with the GAP Tool. Really spoilt for choice with the GAP - alternatively, maybe consider a BBS IQ, which can be left in permanently? Have to admit, I'm not too keen on the IQ black background display with my old eyes, but would be worth talking to EricSDV6 if interested as he has one.

My gut feel is that its loose pins in the OBDII port (or not previously considered, potentially in the GAPTool?) that is shorting out and causing mayhem for me, but time will tell.

The IQ isn’t Apple compatible. Cross that off the list.

Originally Posted by John_D4

The IQ isn’t Apple compatible. Cross that off the list.

True, but works fine on Android and background colours, themes etc are selectable.

Gavin - just further on your dramas and a possible explanation. My comments relate to the D3 but the D4 is similar.

The diagnostic port is connected to the Central Junction Box, which is also is the interface for the key FOB immobiliser.

A bad connection somewhere could not only cause a short circuit (which when left unattended resulted in the battery drain) but also if 12v went somewhere it shouldn’t have (such as a spike down a CAN Bus line) this could have damaged the electronics in the Central Junction Box.

The diagnostic port connects to a few different places, so possibly connecting the GAP tool then completed this circuit causing things to go haywire.

On the D3 and D4 it also connects to the ABS module and Transmission Control Module in addition to the Central Junction Box.

Plus on the D4 I believe the diagnostic port connects to a device called the “Relay Transit” which sits between the battery and starter motor, plus it connects directly to the Engine Control Module (possibly same for D3 via the Instrument Cluster CAN Bus).

So plenty of places for a rouge 12v supply to end up and do damage if something has shorted out.

What does the immobiliser light do between when you lock the car, then unlock, and then insert key? It should show different flash rates.

Have you also checked all fuses? (Yes I mean painfully all).

Terrible when you sleep at night and think about someone else problems with their Disco.....🤪

The other line of investigation would be the earth connection points starting with the two earth lines from the diagnostic socket.

If the diagnostic socket earth has become free then when you insert the tool it will cause a bunch of problems as has been described before as it seems it must make an earth connection first.

On the D3 one earth point is shared with the instrument cluster, and the second earth point is shared with the key FOB transponder coil. Hmmmm....interesting.

So a bad earth on the D3 could result in being unable to start car, and electronics going haywire when you plug the GAP tool in - same as what you experienced on the D4.

Have not found if the D4 is earthed the same way but it would be similar. Could be as simple as the earth points shared by the diagnostic socket coming loose (remember there are two).

Update: D4 key transponder may be earthed differently but the manual does list bad ground to the central junction box as a reason for why the keys are no longer being recognised.

Just a small addition that I forgot to add after the reply from GAPTool, in case anyone is/was unsure like me.

QUESTION
Have just updated Tool from 3.00.00.2712 to 2728.
I also previously did some upgrades purchased from you a few months ago at 3.02.00.32742 (suspension, Auto trans/transfer case from memory (on Tombies recommendation)
Can I assume I not have to re-insert the custom mods after the generic update to 2728

ANSWER
Correct, they are flashed thus no need to repeat.