350i fuel pump steering module

[TS22112]

After a fuel pump failure on my wedge i now require the red relay looking steering module as i have had to bridge mine but the fuel pump now runs all the time. Does anyone know were i can get one?

[Wedg1e]

I have a few spare if you get stuck. Rimmer Bros may do you a new one: alternatively there's next to nothing in them, anyone who's halfway competent with a soldering iron could replace all the components in 5 minutes (a couple of 10p diodes and three 3p resistors as I recall).

Decisions, decisions

[vampire222]

Yeah it's an easy fix to do yourself if you're a bit handy with electronics. Makes it work for lotsa years to come too and they cost an absolute fortune new (a landrover dealer quoted me something like 40 quid for it here)

[honestjohntoo]

This diagram shows the Steering Module innards and how they are connected.



If you need to know what components to purchase, take off the top, visit your local Maplins and tell them you need equivalent diode(s) (maximum 3 off) and the single matching resistor.

FYI, these units do rarely go wrong, having a more likely connection problem with the contacts in the 5 pin relay base.

[TS22112]

Thank you for your helpful relies. and thanks honestjohntoo for the diagram.
Maybe this is not my problem but the resister appears to be burnt.
After replacing my failed fuel pump i had no live, i checked the fuse which was ok but no live and bridged an ignition live to the fuel pump fuse. The pump now runs all the time the ignition is on.
My old pump was dead shorting but did not blow the fuse so what else could have blown?
Any further suggestions please.

[Ian350]

I bought one of these 6 months or so ago. I tried many, many places and in the end the only person who seemed to be able to get one was Neil at TVR Car Parts (I think that's the right name). And yes it was just over £40.

[honestjohntoo]

Generally the world is lousy with S/H Efi steering modules in breakers yards that deal with the RR/LR classic models of the period. Particularly in the London commuter belt, so many of these cars died in motorway crashes or simply wore out. Check your yellow pages for breakers in Surrey.

[honestjohntoo]

My diagram below has more information for you, regarding the actual components inside the SM.

The resistor is specified as a 'fusible resistor'.



If your resistor has been overheated and blown (easy to check with a multimeter) that means there had to be a serious malfunction of the fuel pump relay or its socket.

One hopes that such a fuel pump relay malfunction has not damaged the delicate contacts inside the AFM on pins 36 and 39.

Contrary to my earlier advice, getting a replacement fusible 2.7 ohm resistor may take a bit of googling

https://www.google.fr/search?sugexp=chrome,mod=8&a...

so the easiest route has got to be tracking down a S/H SM.

---

Moving on - my Efi SD1 has no conventional fuse in the pump circuit, perhaps the TVR is different???

Assuming not, if your pump went short circuit as you describe, then it would seem the most vulnerable components in the circuit would be the Fuel Pump relay contacts and/or the Fuel Pump 1.2 ohm Resistor. This would encounter about 10 amps dissipating as much as 120 watts, way too much for both components.

It's hard to say whether such a large, damaging current in the fuel pump circuit could also have caused the problems with the SM blown resistor.

Technically (circuit-wise) not, but if some of the wires around the SM socket have melted, anything is possible.

To eliminate that possible cause you have to visually inspect that part of the wiring loom.

Edited by honestjohntoo on Wednesday 4th July 20:41