I can double check tonight my R52 is in the garage. Staying out of the salt.

 

Thanks for the reply, I think it's the run position but I need to check
I did take a video, but maybe should have left in ACC for a while to see if it ran like the op's

​​

 

Hi just to answer you questions, only happens in the second key turn position (assume first is acc, second is run)
And it ramps up, as per video above.
Haven't driven or for a while now, it's not my daily and I haven't got around to sorting a few bits on it yet (oh and it's an R52 and weather isn't ideal at the moment !) But it does start and run ok, battery terminal voltage is 14.x when running, so alternator appears to be working.

 

I just double checked my 2005 MCS. The PS pump does NOT run in ANY key position with the engine off. I put it in RUN like yours, no pump. Tried to turn the steering wheel, confirmed no power steering. Start it up and the PS works.

 

Beat me to it. Yep i thought it got power in second position key on.

 

Thanks both of you for taking the time to check this, much appreciated

Now just need to narrow down if it's the pump or alternator at fault
Not sure of the best way to do this, but don't really want to blindly replace one of them and hope for the best 😂

 

Oh definitely, 100%. I really, really disdain throwing parts at a problem, hoping for the best.

I'm not sure what the test is, seems like there must be some electrical meter tests that can be performed on the alternator. You'll have to check the manual and internet for that. Or maybe this forum. My gut tells me it's probably not the pump. I worked on mine a long time ago. But I seem to remember there are two large wires to bring power straight from the fuse block, and some smaller control wires the flip a relay in the built-in control module. Those wires would get power when the car calls for it, that is, engine running and steering wheel moving. In my case the pump was just sitting there running in the garage because that control relay got stuck "closed", so pump ON even with the key off. Your problem is more subtle, in that it comes on at an odd time, but not all the time. So your pump relay is not fused closed. I don't think the pump module has that capability, so it must be coming from somewhere else. The slow ramp-up thing that alconk describes, I can't make any sense of that.

But here's another question, is the behavior of yours actually a problem?

 

Thanks again
Whether it is likely to cause a problem day-to-day, I guess not, just thinking I'd quite like to get this fault over and done with, before I try and sort another (these minis have a few lol)

I'll have a think what to do
It's not my daily car, in fact not in use at all currently
But would like to know it's done too
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Can anyone advise of the Violet wire's function on this diagram please?

The other wires are pretty self explanatory
Ground, Permanent live, ignition switched, signal from alternator, and then the Violet...

 

My first question about the control circuit is, where’s the ground? Green/wht is keyed hot, so ground must be YEL or VIO. I do wonder if the VIO is the ground, that could explain why it connects to so many different things. I bet that’s the case, and YEL tells the control unit that the engine is actually running.

BTW, I also think the PS pump only runs when you are steering, that it turns off in between. I seem to remember noticing the sound one time. Can anyone confirm if that’s the case? If so, that control must be built in

 

It makes noises and when you turn it makes more noise. Like a whirl noise. So it runs and then runs more when you turn.

 

Thanks guys

For PSP connector,
​​​​​​I'm thinking that if yellow has NO voltage when engine NOT running, then that would be correct and as expected

If yellow HAS voltage while engine NOT running, then PSP incorrectly thinks alternator is running, and it's likely the alternator at fault somehow

maybe Violet is some signal to say steering wheel is being turned then...

 

VIO/WHT is probably a bus wire. I can check when I have access to the Bentley later.

 

Thanks
I can see it goes to X9397 but don't know what that is
If it's a bus wire is that just a signal to/from ECU in layman's terms? Assume that signal isn't likely to cause my issue...

 

Looks like it's the diagnostic bus.

From the manual:
"A small electric fan is used to cool off the EHPS. It is mounted on rubber bushing to the subframe to prevent vibrations from transmitting to the chassis. There is no connection nor communication between the EHPS and the cooling fan. The EHPS cooling fan power is supplied from a relay that is activated by the "same" wire that supplies power to the engine cooling fan. When the EMS2000 activates the engine cooling fan, the EHPS also gets power up."

"There are two modes of operation for the EHPS: no steering assistance and steering assistance. With the engine running and no steering assistance required the pump operates at approximately 80% capacity at a speed of 3,500 rpm. Movement of the steering changes the hydraulic pressure within the circuit which in turn affects the operation of the pump, this is identified at the control electronics by the increase in current, the pump speed is increased to 4,500 rpm and now operates at full (100%) capacity. The unit's DC motor, is capable of drawing a maximum current of 120 Amperes, but running at an average 11.5 Amperes, powers the system. In standby mode with the engine running but the vehicle stationary the draw is 7.0 Amperes ±10%."

"The EHPS consists of two connections:

2-pin cable connection

• KL30
• KL31

3-pin connector

• KL15
• KL61 (used to determine if the engine is running)
• Diagnosis bus (used for communication with the control electronics integrated in the pump)

The pump motor is activated only if the engine is running. If the pump overheats the pump will reduce output to 80%. If the temperature keeps rising, the pump will eventually shut down to protect itself (electronics) from damage."

 

I suspect your answer lies in KL61, but my brain is a bit mush at the moment. I'm not sure if I have the mental bandwidth to dig further tonight.

edit: I bet KL61 is the yellow wire, and something there is shorted downstream. The green/white wire that supplies power to the controller is hot in on or start, but you have a running pump when the key is set to on with the engine off.

 

I'm pretty sure there's more info on this in the Bentley towards the back, but I don't have my physical copy. I think the digital copy I have is incomplete, but I'm not positive.

edit, part deux: I expect that the black/yellow wire here is the one telling the cluster that the alternator is charging and to turn off the light. Probably the same signal the pump controller is using to know the engine is running.

 

Thanks for looking into this so much, really appreciate the help

Yesterday I came to a similar conclusion after finding these wiring diagrams
I could test if I have voltage at the yellow wire at the pump without engine running
If there is power there, I likely have an alternator issue.
If there is no power, it's likely an issue with the circuitry in the pump itself, as it's running without that voltage it should look for.

I did read 'somewhere' that the pump looks for a higher voltage on that yellow that the battery voltage, thus knowing that the alternator is running

 

I'm still curious though, where's the ground on that control circuit? If the violet wire is CANBUS, then the yellow or green can't both be power.... One of them must be ground, right?

 

Honestly don't know
Is it not a common ground for everything, there is the brown wire?This is a little beyond me to be honest!

 

To be pedantic, the violet is d-bus, not CAN bus.

I agree with the suspicion that the controller grounds through the pump. I don’t know for sure though, and I’m not actually familiar with how those are connected internally.

 

Thought it was worth an update...

Finally got an hour to get under the car and multimeter the psp control plug
With the key in the on position, but engine not running:
Pin 1 Green 12v
Pin 2 Yellow 0.6v
Pin 3 Violet 10v

Engine running:
Pin 1 Green 13v
Pin 2 Yellow 13v
Pin 3 Violet 13v

All very approximate readings, but I think that's pretty much what I'd expect.
Pin 2 from alternator goes from 0.6 (when not running) to 13+(running)
I'd assume the 0.6 wouldn't be enough to trigger the pump to start.

Long story short, with my limited knowledge I think the fault is in the pump rather than alternator or wiring
Happy to hear any other opinions though!

 

The pumps are known to trap the carbon dust from the brushes and coat the circuit board causing it to short. There are some videos showing how to clean it out, but I’m not sure how safe that is or how long it will last.

Have you run your VIN on the mini USA website to see if it’s part of the power steering pump recall?

 

Thanks
Yeah I have read up on these failures, and understand the likely causes

I'm in the UK, pretty sure there's no recall for this fault here
There's no outstanding recalls on my vehicle anyway, according to the Mini site

 

Relevant to this thread: I recently replaced a failed alternator (rear bearing gone bad) in my '05 MCS.

With the alternator removed, the PS pump runs when the key is in the ignition position (i.e. all electrical accessory operational, but engine off).

With the new alternator installed, the PS pump runs only when the engine runs.

So the PS pump can be fooled into believing the engine is on if there's a problem with the voltage regulator in the alternator.