Abs problem

MELBUTCH · Jul 31, 2012

I have a 2001 4.0 Westminster running on petrol/Lpg.
The ABS, TC, and Handbrake lights have all come on with an ABS Fault Warning Light showing.

The car is working perfectly and when driving the breaking is OK.

I took the car into my RR garage this morning for a diagnostic check.

The check showed. No power to the ABS/Brake pump. Further manual checks to fuses and relay confirmed power was getting to the pump.

The garage advised they carry out tests on the wiring to find the fault.
Has anybody had a similar problem?
I would welcome any advice to rectify the problem.
Many thanks
Melbutch

aerofabrique · Jul 31, 2012

Burnt out pump or pressure switch fault. You have around 30 good braking applications left on reserve after the pump gives up before the whole thing fails.

Is the pump actually running with direct power?

Well documented on here... Due welded or stuck abs relay (black one) do a forum search.

You need to be more specific as to what was tested to the abs module under the fluid resivoir or the pump with the accumulator on? Both have very different price tags when it comes to replacing.

Equally may just be a sensor that got knocked out and needs putting back in if everything else is ok....when you say rr garage what do you mean?

Datatek · Jul 31, 2012

ABS ECU is a possible.

wammers · Jul 31, 2012

If there is power to the pump but it ain't running, can't be a lot else but pump motor. It is switched from pressure switch via relay 17 and fed direct from MF3. If there is power to it and it is earthed it has to run or motor is duff. However if it is running then it has to be ECU.

Datatek · Aug 1, 2012

If the brakes are working normally, I can't see how it can be the pump.

wammers · Aug 1, 2012

If you look at the diagrams there is a link to pin 8 from pump, to pin 9 from pressure switch that tells the ECU whether the pump is powered or not. Either that link is broken or the ECU is duff.

MELBUTCH · Aug 1, 2012

Many thanks to all of you who have replied.

I was at the garage this morning. They assure me the pump is working and the black relay is ok. The garage thinks it is either a sensor or pressure switch problem I will mention the ECU to them. The car is booked to go in for repair next Thursday. The garage is Range Rover Man based in Hailsham East Sussex. A top garage for Range Rover repairs and servicing.

Melbutch

wammers · Aug 1, 2012

The pressure switch pulls down relay 17, it also feeds a signal to pin 9 on the ECU to tell it the relay is active. When power to pump comes from MF3 via relay that signal is put through pin 8 of ECU. So basically when relay is pulled by pressure switch, it tells ECU that relay should be active. Power coming from MF3 to motor confirms that command. Only if either of those feeds are broken or the ECU is not recognising the signals would a "No power to motor" fault be generated. Still think it's the ECU.

MELBUTCH · Aug 11, 2012

Many thanks for all your replies.
The pressure switch was the problem.
New unit fitted.

Melbutch

Abs problem

MELBUTCH

Member

aerofabrique

Active Member

Datatek

Well-Known Member

wammers

No longer with us, RIP

Datatek

Well-Known Member

wammers

No longer with us, RIP

MELBUTCH

Member

wammers

No longer with us, RIP

MELBUTCH

Member

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