Starter button / fuel pump doesn't kick in advice?

[Juddder]

Hi everyone

Went to take the Cerbera for a bit of a spin this afternoon, and the fuel pump / starter button process doesn't seem to want to kick in??

Alarm - on off with remote fine and lights flash once / twice
Doors - open and windows drop fine both sides
Lights - work fine
Horn - works fine

Checks:

Silver key in dash turned fully to the right - Check
Dashboard alarm light off when trying to start - Check

So basically I go through the whole standard pre-flight procedure - get in car, disable alarm with fob, check dash light is out, check silver key turned to the right fully, listen for fuel pump noise, press start button - but I don't get any fuel pump noise and the start button doesn't fire starter motor.

Any good ideas where to start to diagnose the problem?

Things I did notice:

Pressing the air nobs in turn them on doesn't have any effect (but guess this is because the car isn't started)
Steering wheel windscreen wiper buttons have no effect (but guess again that this is because the car isn't started)

The car was working fine when I last parked it, and the battery is registering 12.8V after being charged so don't think that's the issue.

Any advice much appreciated!

Alex

[kevin63]

It might be an idea to check the big fuse, the 100amp one, you never know.

[sonnylad]

Sounds more like silver key to me.

[pmessling]

the fans will run without the car starting, as will the wipers, lights etc,

how many times you touched the silver key?

[Juddder]

A couple of other pointers to help the potential sleuths out there

- I _do_ use the silver key to turn off the battery / save power when I'm not using the car, and that whole bike key socket is slightly loose in the dash

- Neither the fuel pump or starter do anything which points at one of the cut-outs still being enabled, although the dash alarm light DOES go out so I don't think it's the alarm

- Fuel pump and starter are on different fuses according to the manual (13 Starter / Drivers door lock, 19 Fuel pump / Lambda heaters) and the door is locking so wouldn't indicate that a fuse was the issue.

So... my thoughts are maybe the silver bike key socket has a wire lose?

Any good tips how to get to the back of it to check (I can run a multi-meter over it tomorrow to check continuity if I can get to it :-) )

And thanks for the big fuse suggestion - manual says the biggest fuse is 25A so not sure where that one lives!

[kevin63]

You have an 100amp fuse which is located in the Vee of the engine right at the back near the baulk head.

[jackwibble]

DONT TOUCH THE SILVER KEY EVER!!!
Ok rant over if you have been using it your probably correct and a wire is Fubared (sorry FUBES) at the back of the housing they really are a cheap piece of crap!!

[pmessling]

easist way to get to the back of the key switch is to remove the dash instrument pod, you'll then be able to to down into it, although your head will be pressed against the screen.

I think there is a valuable lesson to learn here judder!!!

[Gazzab]

As said don't touch silver key. It's a pita to fix.

[Juddder]

Gazzab said:

As said don't touch silver key. It's a pita to fix.

B*ll*x

OK - I think the strategy tomorrow is going to be to pull the radio out (I fitted the current one so know how to get that out easily enough) and then I should be able to 'somehow' get my fingers down to the back of the SILVER KEY and try and un-tighten the locking bolt.

I can also pull the ash tray out on my dash (there's a secret cut-off switch in there too incredibly enough (earlier post on Piston Heads when I first got the car trying to work out WTF it was!)) and access it that way maybe.

If I can get the SILVER KEY socket out, then I might just replace it with a push switch - much easier if anyone else has done the same?

[pmessling]

remove the top dash pod, save struggling through a tiny hole.

Remove the knee panel, then the dash pop, you can see right down into the behind of the silver key area.

[Tanguero]

kevin63 said:

You have an 100amp fuse which is located in the Vee of the engine right at the back near the baulk head.

The 100 amp fuse is only in the charging circuit between the alternator and battery. A problem with it would prevent the battery from charging, it has nothing to do with these symptoms.

This sounds like either a wire dropped off the silver key switch or an immobiliser problem.

[Griffithy]

Had something very similar yesterday. No Petrol pump and no start.
I disconnected the battery for a few seconds. Armed and disarmed
it and afterwards everything worked fine.

[ridds]

Tried pressing the alarm fob button with the ignition on?

[dempsey]

This is a relatively common fault (search for similar threads).

Often the culprit is the immobiliser where the fuel pump and starter motor circuits are
routed through it but fail to reach a critical required minimum voltage.

If you know what you're doing it's quite easy to temporarily bypass the immobiliser (which
will invalidate your insurance) to check that it's this.

Having said that, I checked this and all the other possibles (relays, big fuse etc) and in the end
it was the black button switch itself which needed replacing.

[Jhonno]

dempsey said:

This is a relatively common fault (search for similar threads).

Often the culprit is the immobiliser where the fuel pump and starter motor circuits are
routed through it but fail to reach a critical required minimum voltage.

If you know what you're doing it's quite easy to temporarily bypass the immobiliser (which
will invalidate your insurance) to check that it's this.

Having said that, I checked this and all the other possibles (relays, big fuse etc) and in the end
it was the black button switch itself which needed replacing.

I thought it was the starter circuit that was the one that seems to suffer from it..

Also the temp fix doesn't bypass your immobiliser.. So insurance is fine.

[Mr Cerbera]

The ECU turns the fuel pump on by grounding pin 25 but it will not do that if the Inertia Trip has been tripped (This is identified by the MIL(F) light illuminating for 3 seconds when the black button is pressed).

If that's not the case then check that Relay No. 4 has a 12V supply to pins 85 & 30/51. If it does not then check Fuse 19.

HTH

[Juddder]

dempsey said:

Having said that, I checked this and all the other possibles (relays, big fuse etc) and in the end
it was the black button switch itself which needed replacing.

Thanks for the advice Dempsey - which black button switch did you need to replace?

The only ones i can think of are the one by the alarm dash light (that I thought was to lock the doors and boot from inside) or the one on the key fob...

I've two key fobs so I'll try both (and will test disconnecting the battery and reconnecting, and turning the alarm on/off while trying to get some life from it )

I'll also check the fuses as per Mr Cerbera's advice and report back!

Final note is that the immobilise light DOES go out, so the immobiliser does appear to believe it has disengaged!

Edited by Juddder on Sunday 3rd February 13:07

[jackwibble]

I think he means the starter black button on the steering wheel?

[Juddder]

jackwibble said:

I think he means the starter black button on the steering wheel?

Ah.. Yes that would make sense

Forgot about THAT really important one