Thread: Safe to drive D2 with ACE pump bypassed?

Just be aware that there will be less belt contact on the power steering pump pulley although in my testing I couldn't get the belt to slip. The shorter belt was my remote area get home solution.

Did you go for a drive when testing and if so did the amber Ace light come on?

Originally Posted by Graeme

Just be aware that there will be less belt contact on the power steering pump pulley although in my testing I couldn't get the belt to slip. The shorter belt was my remote area get home solution.

Just read the workshop manual which was helpful.

It describes ACE failure modes but doesn’t state what happens with a loss of pump pressure.

But it does provide a solution to deactivate ACE.

Just by cutting out ( eg with a simple switch in the wiring harness going to the ACE ecu ) the road speed input or the engine speed input the ACE will go into the “locked bars” mode and is safe to drive.


Fluid will keep circulating from the pump to the ACE valve block only, not to the rams, so I won’t loose fluid.

So a simple ACE OFF switch I can install in the car to provide a good backup along with the short drive belt should the pump fail.

Originally Posted by simonmelb

Just read the workshop manual which was helpful.

It describes ACE failure modes but doesn’t state what happens with a loss of pump pressure.

But it does provide a solution to deactivate ACE.

Just by cutting out ( eg with a simple switch in the wiring harness going to the ACE ecu ) the road speed input or the engine speed input the ACE will go into the “locked bars” mode and is safe to drive.


Fluid will keep circulating from the pump to the ACE valve block only, not to the rams, so I won’t loose fluid.

So a simple ACE OFF switch I can install in the car to provide a good backup along with the short drive belt should the pump fail.

I will look into to a ACE off switch too but I have a speedo correction unit installed for my taller tyres which intercepts the Road Speed Signal - and I wouldn’t want to loose my speedo too…..

Simplest way to send it o "locked bars" is to remove the ACE relay(R14) and if the leak is in one ram that will stop too cos the fluid will be recirculated

A leak at a ram will eventually loose enough oil for the bars to become floppy, but otherwise no harm.
The pump needs to be bypassed if the reservoir is out of oil as it will very quickly destroy the pump including its bearings.

Thanks all!

Reservoir still nearly full so will pull the relay and take a drive to buy a new ram. Hopefully Karcraft import them at a decent price.

I’m wondering whether a good hydraulics shop would be able to refurbish one of those. I suppose someone must have tried.