101 replies to this topic

[DaveyC]

My car wouldn't start this morning after changing the oil filter last night - I'm getting code P1512 which relates to a throttle body issue. I assumed I had pulled some connection loose when manhandling the oil cooler adaptor but I've just checked and all the wires going into the throttle plug are functioning. I've tried clearing the code but the code immediately reappears as soon as ignition is switched on.

 

The throttle body looks pretty clean and the butterfly opens and returns under spring easily.

 

Is there a way to check if the throttle body is functioning when it isn't on the car so I can rule it out? Or what voltages I should see when measuring the harness on the car?

 

If it is any help, I don't think the fuel pump is priming but I know on some cars it won't unless all the initial electrical checks are passed anyway.

[CHILL Gone DUTCH]

You get that fault when your relay has gone Normally yellow one in boot

[DaveyC]

Cheers, I'll take a look tomorrow.

[CHILL Gone DUTCH]

Happened to me when I tried to start car without putting relays in recently, lol

[DaveyC]

A bit more background to clear things up.

 

The car turns over, but does not start. I believe this means the yellow relay is OK otherwise the started would not work at all?

 

I've tried cleaning the two harnesses in the N/S rear wheel arch and tested continuity across a number of the wires so I think everything is OK there.

 

In its current state I'm getting this throttle body error, the fuel pump does not run and my charge cooler pump doesn't run (it is tapped into the brown/pink wire in the aforementioned wheel arch harnesses and usually comes on with the ignition).

 

Whilst I was messing around trying to find any signs of dodgy wiring I unplugged the coil pack and noticed the charge cooler pump started to run. It stops running as soon as the coil pack is plugged in. I can't check to see if the TB error goes away in this condition because the OBD reader gets disconnected when the coil pack is unplugged.

[CHILL Gone DUTCH]

Fuel cut of switch ?

[DaveyC]

I've tried pressing that several times, with and without the ignition on.

 

Also just checked the coil pack for water - it is bone dry, as are the plugs.

[CHILL Gone DUTCH]

ARe you able to measure voltages around the brown relay next to yellow one I think that does fuel pump Or maybe it's the actual fuel pump it self

[CHILL Gone DUTCH]

there are also two yellow fuses next to relays worth a look

[CHILL Gone DUTCH]

Could also be a earthing issue Or coil pack

Edited by CHILL Gone DUTCH, 29 January 2015 - 12:07 PM.

[DaveyC]

I'll go and prod the relays with the miltimeter now.

 

I've checked the earth points I know of and they all look OK.

[CHILL Gone DUTCH]

Are you Supercharged or NA

[DaveyC]

Supercharged.

[CHILL Gone DUTCH]

Is there a chance the crank sensor was knocked

[DaveyC]

I don't think so.

 

I literally drove the car home, switched off, unplugged the throttle body, changed the oil, plugged the throttle body back in, tried to start it.

All happened in the space of an hour.

 

I'd expect the fuel pump to continue to work if the crank sensor was the culprit.

[CHILL Gone DUTCH]

Mmm The throttle body has to have some wires reversed/ repositioned which some time is done by soldering on to the new position Maybe worth looking at loom around TB plug or maybe the pins within the plug have come out

Edited by CHILL Gone DUTCH, 29 January 2015 - 12:50 PM.

[DaveyC]

I've checked the wires at the plug, there is good contact between the wires as they enter the plug and the pins themselves.

[CHILL Gone DUTCH]

Can you film it ?

[DaveyC]

House move now complete. Time to look at the car again. Is there anyone local to Warwickshire who runs an lsj throttle body and wouldn't mind plugging mine into their car to check it works so I can rule it out? You wouldn't even need to unbolt anything, just unplug yours, plug mine in, flick ignition on, see if pedal controls butterfly. Should only be a 5 minute job and could save me a lot of time chasing the problem elsewhere.

Edited by DaveyC, 06 February 2015 - 06:46 AM.

[vocky]

seen this fault recently, was a duff brown relay