ECU and Alarm

[matttav]

well... my fuel supply problem is not the Pump or relays/fuses.. which puts it down to the ECU or alarm

Help....
I have a 93 4lt and the alarm appears to be working ok.. but is there any common probs I can check in case its cutting the fuel supply.... or perhaps a ECU reset technique??

I have read the bible faithfully and drawing a blank on
where to look etc

Cheers all

PS If anyone had a decent wiring diagram they could email/fax I would gladly beg pathetically

[shpub]

Errrr it might help to describe the fuel problem...
Not all of us have telepathic powers!

Is it coming on? Is it dying? Does it get power at the pump end?

Common fault is either the fuel pump relay in the footwell or a dead immobiliser.

>> Edited by shpub on Wednesday 18th June 19:46

[spend]

According to my Rover info:

With the ECU plug disconnected - temporarily earth pin 16 - you should get battery voltage between fuel pump relay and earth. If not suspect ECU.


This is from Range Rover Tech doc, but I've found it to be reasonable diagnosis.

HTH, Dave

[sparkythecat]

I had a similar problem. It turned out to be corrosion in the cheap and nasty loom connecting block behind the trim in the 'B pillar' (that void space between the door striker and the rear wheel arch)This meant there was no current getting to the pump. The trim is only velcro'd on so it's easy to check.

[macone48]

Fuel pump supply goes through Central Door locking Control Unit, under dash top, via the alarm, also under dash top. Wiring colours appear to be Green/Black. Fuel Pump power also is via interia switch above passengers knees (after lowering document holder).

If your fuel guage reads zero despite having fuel in tank, the alarm is isolating your fuel pump i.e. it is on and in imobiliser mode!!

[matttav]

Sorry.. to explain further... fuel pump not working when I start up... but it works fine with a direct supply. Relay has been testing and is fine, fuses fine,

Thanks for all the pointer so far... I can start checking them

Any tips on best access to the alarm?

.... Lets hope the rain holds off after work!!

[macone48]

To get to alarm you need to undo the two nuts on dash top. You get to these from Document holder under dash above passengers legs. This also gives access to inertia switch which also can remove power to fuel pump. Nuts are: One is at front and the other at the rear. The top will "lift" up sufficiently to get at alarm & wiring. Does sound like either Alarm, Central Locking CU or inertia switch are "cutting" power to pump. Yellow with black tracer and Yellow wires at Inertia switch and Alarm/Central locking CU. Have fun ;-)