Slow power steering pump???

[dsakko]

I've searched the forums and can't find another case like this. I have an absolute lemon. After fixing a blown water pump the power steering is now acting up.

Fault:
- When I turn on the ignition the power steering pump immediately starts to spool up (Doesn't wait for me to start the engine).
- It takes a long time (maybe 30 seconds) for the pump to come up to speed, then works perfectly as if there is no fault (makes the usual noises, and the steering feels perfect).
- NO fluid is being lost from the power steering system. There is wetness around one of the high pressure joints but it's been like that for its whole life.
- The ECU is reporting the P0500 fault (speed sensor "A") - gotta look at that. Possible that the dealership left a wheel sensor unplugged after replacing the water pump.
UPDATE: Also, when you turn on the ignition the alternator charging light doesn't come on.

Fix:
During the replacement of the water pump they knocked the connector loose on the back of the alternator that supplies the alternator charging light signal, hence the software was putting the pump into low power mode rather than spinning it up quickly. Simply plugged it back in and away we go!

Car:
Feb 2002 Mini Cooper - Aus spec.
103,000 km

Anyone know what the bejesus is going on??? And what the likelihood that it will fail totally???

[MINIMANIAUK]

The steering is speed sensitive, 2 speeds as I remember and the speed sensor is used to dictate which mode it runs in -so looks like that is the problem with luck-not that you seem to be having any!!

[dsakko]

Thanks for the advice but no good. Checked the wheel sensors and all are plugged in. Cleared the fault and been on a couple of trips and the speed fault code hasn't come back.

I'll keep investigating and post what I find, but I'm thinking it might be the pump control module acting up.

[westycoopers]

i just hope for your sake that the power steering pump isnt on its way out, my mates a mechanic and he said that a new power steering pump is £800!!!!!!!!

[MINIMANIAUK]

A bit less than (£800 )- nearer £400

[mab01uk]

Quote: Originally Posted by westycoopers (original)

i just hope for your sake that the power steering pump isnt on its way out, my mates a mechanic and he said that a new power steering pump is £800!!!!!!!!

Only £175 for your own PS pump to be repaired or an exchange reconditioned pump from BBA-Reman with 2 years warranty :-
BMW Mini Power steering pump rebuild service on eBay, also, Audi, Car Parts, Cars, Parts Vehicles (end time 18-Jun-08 11:30:00 BST)

[dsakko]

I hope it's not the pump too! Thanks for the advice all, I shall keep an eye on the fault codes and the fluid level (no leaks so far) and let you know what I find.

For now it's driving well, and the last 3 times I've driven it the pump has spooled up almost instantly. Here's crossing my fingers I don't find the fault the hard way...

[dsakko]

Update: Things are getting weirder....

1. I pulled off the signal and power connectors off the pump and cleaned them up. They looked perfect, but I cleaned them up anyway. No effect.

2. I traced back the earth for the pump (located underneath the fuse/relay holder under the bonnet (next to the battery on the Cooper and next to the air filter on the S). Cleaned that up and no effect.

3. I've discovered that if I turn the ignition key just enough to engage the starter motor lockout without actually starting the car (that mechanical thing that stops you turning the key after it's started, and you have to turn the ignition off then on again to start), then the pump fires up PERFECTLY first time every time.

It's looking more and more like an electrical problem, but not with the pump. According to the schematics in the Bentley manual the pump is activated by the ECU, and that appears to work when it feels like it. Maybe a loose wire / bad contact in the ignition switch???

[C.Noble]

When you turn the ignition on, without the engine running, does the battery charge warning light come on?

[dsakko]

Ooooh, GOOD CALL! No battery charge light, only the oil pressure light.

So what does that mean? This all started after they replaced the water pump and fan (ribbed v) belt - have they mucked something up with the alternator?

[C.Noble]

If you look above the alternator, you will see a three wire connector and a black inline fuse holder, check the fuse, it will probably be ok, but worth checking anyway.
It most likely one of the wires at the back of the three wire connector (the black/yellow I think) will be broken, its a doddle to fix, just bypass the connector on that wire with a repair peice.

hope this helps.

[dsakko]

Thanks heaps. Not sure how to get to it yet - on the Cooper with the water pump in place looks like you need to get the radiador out or the manifold off. So little room and such fat fingers....

Will keep you posted.

[C.Noble]

You should not need to remove anything other than possibly the black plastic cover over the fuel rail (cant remember, cos our cars dont have them anymore!) The connector is on top of the alternator, and is joining two harnesses about 50mm to the right of the EVAP purge solenoid, not plugging into the alternator itself.

[dsakko]

Found it. No signal on either pin (there are two wires going in, 3 coming out). Attached a pic.

Over the weekend I'll whip the radiator hose off (the one that runs under the manifold) and I should have room to get to the back of the alternator.

[--Mike--]

I'm experiencing the same sort of problems with my MCS - the power steering is heavy sometimes when starting off and will occasionally cut out while driving. Switching off and back on again sorts it out.

Does anyone know where the connectors from the alternator are on a Cooper S? Comparing the picture above to my engine bay, I cannot see the wiring.

Cheers