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MINI MINI Cooper, MINI Cooper S: 2002-2006 How do I bench test the power steering pump


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Last Post: Jun 17, 2017 11:40 AM Last Post By: WojtekMCSJCW
Courier

Posts: 4
Registered: 03/27/08
How do I bench test the power steering pump
Posted: Mar 27, 2008 4:31 PM
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2004 Mini power steering pump failed. Had it rebuilt by BBA Remanufacturing. Pump did not work when I reinstalled it. Upon further checking I discovered that terminal 1 and 2 of connector x6975 were bent flat. I straightened the pins but the pump still does not work. Is there a way to bench test the pump to determine if the problem is with the pump before checking for problems in the wiring? Fuses are okay and I am receiving power at the x13441 connector.

Message was edited by: Courier

Nick Czerula

Posts: 270
Registered: 10/16/06
Re: How do I bench test the power steering pump
Posted: Mar 27, 2008 5:53 PM   in response to: Courier in response to: Courier
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Hi,
I can give you a quick pun out description.

connector x13441 pin 1 brn chassis ground 0.0 volts
pin 2 red Battery positive, (should be same as battery volts.)

Connector x6975 pin 1 grn/wht Battery positivr
pin 2 yel battery volts.
pin 3 in the k-line. Will be less than 12 volts.

The pump does not run unless it senses pressure. You will not be able to bench test it. If the voltages are good to the pump. As described above. The pump is not good. Something may have gone wrong during the rebuild process.

Courier

Posts: 4
Registered: 03/27/08
Re: How do I bench test the power steering pump
Posted: Mar 27, 2008 9:09 PM   in response to: Nick Czerula in response to: Nick Czerula
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Nick,

Thanks for the info. Connector x13441 pin 1 and 2 test correctly. Connector x6975 pin 2 shows 15v while pin 3 shows 4v. Does this mean the pump is good or bad. Sorry I don't seem to understand all this good stuff but I'm sort of on my own with this repair. The dealer is three hours away and the auto electric shop I took the pump to for possible testing told me they never heard of an electric power steering pump and after looking at it said they had no idea how to test it.

Again thanks for the help and patience.
Nick Czerula

Posts: 270
Registered: 10/16/06
Re: How do I bench test the power steering pump
Posted: Mar 27, 2008 9:50 PM   in response to: Courier in response to: Courier
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Those numbers all sound ok. You must have a defective pump. Have you tryed buying a reman pump from MINI? They will ship it to you.
Courier

Posts: 4
Registered: 03/27/08
Re: How do I bench test the power steering pump
Posted: Mar 28, 2008 9:21 AM   in response to: Nick Czerula in response to: Nick Czerula
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After doing the check you suggested I contacted BBA Remanufacturing this morning since they rebuilt the pump and offer a lifetime warranty on the repair. They said to ship it back. I'll let you know how it goes. Hopefully by next week as their turn around time was less than a week.

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FlyTheCoop

Posts: 87
Registered: 04/24/06
Re: How do I bench test the power steering pump
Posted: Mar 28, 2008 11:09 AM   in response to: Courier in response to: Courier
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I an sorry to hear about your pump troubles....I have some more information on the operation of the pump.

On the 2 pin connector, pin 2 goes directly to battery + through a 100a fusible link located on the bottom of the fuse box under the hood (aka terminal 30). Pin 1 goes directly to battery - (aka terminal 31). These two wires provide the heavy current to run the pump.

On the three pin connector, pin 1 should have battery + when the key is on (aka terminal 15). Pin 2 goes to the alternator and should reflect the output of the alternator when the engine is running (this signal is used to tell the pump electronics that the engine is running). The pump will not run if it thinks the engine is off unless its bad). Pin 3 is used to communicate pump errors on the diagnostic bus.

The pump operates in two modes: standby and full output.When the car is idling and no steering demand is present the pump is in standby mode; it runs at 80% capacity and an rpm of 3500...the current draw is 7amps +/- 10%.

When the steering is turned, the pump senses a pressure change in the hydraulics..this change causes the pump to switch to full output and runs at 100% and at an rpm of 4500.

If the steering is turned to either end of its travel, or if the wheel hits a curb, the current to the pump is momentarily reduced to 30amps.

The battery voltage is monitored, it must be between 9 and 16vdc or the pump will not operate.

If the temperature gets to 230f (110c) the operating current of the pump will be reduced.

The pump contains the controller and will produce the following errors if a problem is detected.
Power supply fault
Electric motor fault
Fault caused by excess temperature
Control module fault

You reported pin 2 at 15vdc, I am not sure but this may be a bit on the high side for the alternator, could it be there is a concern with the charging system regulator?
Once it hits 16vdc the pump motor will be disabled. just a thought.

Hope this helps.
Courier

Posts: 4
Registered: 03/27/08
Re: How do I bench test the power steering pump
Posted: Apr 3, 2008 7:16 PM   in response to: FlyTheCoop in response to: FlyTheCoop
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Got my pump back from BBA Remanufacturing this morning. They told me the problem was in the pump. I installed it and everything works! BBA Remanufacturing was a bargain at $200.00 even though something went wrong. That seems to be the story of my life. After making the electrical checks you two suggested BBA Remanufacturing had no problem honoring their lifetime warranty. I wasn't even charged for the overnight shipping.
After a month I'm glad to have my Mini back. I read about a lot of problems with Mini's but this is the first problem I've had in four years other than replacing a wiper blade.

Again thank you both for the help.
WojtekMCSJCW

Posts: 1
Registered: 06/17/17
Re: How do I bench test the power steering pump
Posted: Jun 17, 2017 11:40 AM   in response to: FlyTheCoop in response to: FlyTheCoop
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My power steering pump is not turning on. 2 pin connector tests at 14V. Pin 2 of the 3 pin connector tests at 2V when the car is on .5v when car is off.
The system worked fine before i removed the subframe to service LCA bushings. I also had the ecu disconnect for a few days as is was replacing the transmission mount. Any thought on what is going on?

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