More problems with my coupe

[220bhp]

I have just started the car and the diflock green light,the one that indicates the rear diff,is on all the time, and when you press the switch the red light on the switch wont always go of.
Should the green light be on all the time or not.
I take it the red light means that the difflock is ingaged.

[Drummer87]

Hmm you now tricked my thinking.

I thought when engaged it went green or amber. And when not engaged it didn't show anything. But I could be off the mark as I'm not looking at the diff switch alot.

[LHD_Kid]

Should the green light be on all the time or not.
I take it the red light means that the difflock is ingaged.

If it is the old style (I think all 3B's have this), large button type diff-lock switch, the only illumination should be the basic diagram and the word "DIFF".

Once engaged, a triangle lights on the buttoin - similar to the fog light switch and a green light shows on the diff area on the diagram...

Once engaged you will also get the ABS warning light up on the main instrument cluster, to say ABS is no longer operational.

[220bhp]

The diff is locked and wont go of.What worries me is That I have never used it,and did not knowingly turn it on when it locked itself.The first thing I noticed was that the car was hard to park and the ABS light came on.So what would cause it to lock itself and how do I unlock it.
I have been told to run it in reverse and slam the brakes on,but I dont like the sound of that.
Might be alright for an old land rover,but not my s2.

[irishs2]

The diff is locked and wont go of.What worries me is That I have never used it,and did not knowingly turn it on when it locked itself.The first thing I noticed was that the car was hard to park and the ABS light came on.So what would cause it to lock itself and how do I unlock it.
I have been told to run it in reverse and slam the brakes on,but I dont like the sound of that.
Might be alright for an old land rover,but not my s2.

The diff lock actuator may have broken free, at this age they are very brittle. It might be worth a look at the rear axle to see if you can move the arm manually.


This is the position when the difflock is disengaged.

[Monkeymagic]

first off i haven't really had experience of the rear diff yet. but. your fault sounds electrical to me. the rear actuator is vacuum fed. however i would think most faults would be diff not locking due to leaks in system. you obviously have the opposite diff won't come off. if it were mechanical i wouldn't expect all the switch and abs to recognise it. also it sounds like you are having a number of electrical problems.
does anyone know if you can talk to the diff. with vcds

[Monkeymagic]

just a thought attach a mityvac to the black/yellow vac line from the diff controller under back seat. see if when applying vac and pressure the actuator moves.

[Error404]

Sounds like the switch needs replacing to me. The ABS switch is the same as the diff lock internally, try plugging that in instead and see if it gives you proper control of the diff lock. In the mean time you can diconnect the vac line from the diff lock actutor under the rear seat and plug it. That will bypass the actuator and leave the diff lock permenantly off.

[Tonks4x4]

Also worth a check is the one way valve on the vacuum pipe under the rear seat on the passenger side.
If this gives up the ghost it will engage diff lock every time you are on boost.

[Monkeymagic]

i second that about non return valve. been reading some more try manually moving the actuatn
as already mentioned it could be the mech has seized in the on position. could be the vacuum is not enough to pull it off. ha ha pull it off!

[220bhp]

I jacked the car up and moved the lever on the side of the diff ,and it dissingauged,and all the lights went out.I checked the one way valve and could not find any thing wrong.
But I am going to change it.anyone know the part no for a 3b.
I dont want this happening again,so what else could cause it to come on by itself.

[Tonks4x4]

The diaphragm could be split on the rear actuator or the plastic housing could be cracked allowing movement in only one direction.

[220bhp]

The diaphragm could be split on the rear actuator or the plastic housing could be cracked allowing movement in only one direction.

Thanks I will check it out

[220bhp]

The ABS lght started to flicker,and also the green diff indicator,continued to flicker on and of again.When I got home the diff lock had self engaged.
I have taken the one way valve of,and can't see any thing wrong .I can only blow through it one way.
I have now dissconected it and blocked the incoming pink line and both the out going pink and white lines,I assume the white line go's to the vacume resivour.Is this the one that opperates the central locking,which incedentely has recently stopped working. I also pulled the electrical connector of the control box,and pushed the leaver under the.
The dif lock is now of but the ABS light and the green indicator are still on.pressing the ABS switch and the diff switch has no effect.S where do I look now.

[220bhp]

The diaphragm could be split on the rear actuator or the plastic housing could be cracked allowing movement in only one direction.

Just read this again,are these locations on the side of the diff under the car. O.r inside