Technical Pump driving relay stuck

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Technical Pump driving relay stuck

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Mar 31, 2012
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The Selespeed has started dropping into neutral from 1st and reluctant to select Reverse.

Plugging in computer with multiecuscan shows P1769 Pump Driving Relay stuck.

Relays (which I assume are T09 and T10) appear OK. I will need to get them ordered if required but local auto sparky said they appeared OK.

The car changes and drives normally when under way in Manual or Auto.
With engine off I can select all gears without any problem.

Any ideas as to things to check?
 
Is the pump running for the normal length of time (7-10 seconds) when you open the driver's door after the car has been at rest for a few hours?

I'm wondering what triggers that fault code - whether it really is a faulty relay (how would 'it' know?) or whether it's triggered when the pump runs for longer than expected. Check the Selespeed fluid level and top it up to the seam in the tank if necessary.

If the pump is running only for short bursts, then it's likely to be the accumulator at fault. See thread http://www.alfaowner.com/Forum/alfa-147-156-and-gt/327000-baffled-by-a-selespeed-p1769.html and other threads linked therein :)

Actually, it makes sense to me now that a high pressure reading will trigger that relay fault code, as the assumed cause of high pressure is that the relay has stuck 'on' and the pump has continued to run for longer than 10 seconds.

The reality is that the high pressure results from the pump running briefly against a failed (flat, discharged) accumulator. Use MultiECUScan to check your pressure. It should be a gradual rise over a few seconds followed by a steady decline for two gearchanges, then the pump should run again. If it is spiking up and down much quicker than this, accompanied by odd noises (clunks and groans), then the accumulator is the problem.

The accumulator is part number 71751195 and I'm fairly sure there is stock in Cambridge at www.fiatparts.co.nz, 07 827 8918.

If the pump seems to run for the correct length of time, sounds normal, and yet the pressure readings are irregular, then perhaps a faulty pressure sensor (reporting a wrongly-high reading) is a possible cause. Seems less likely, but always good to have a backup plan/next thing to try.

I think you do have a pressure problem though, as two particular actions consume more fluid pressure than anything else:
1) Selecting reverse (both gearchange actuators full-travel), and
2) Holding the clutch disengaged while 1st gear is selected.

And those happen to be the circumstances you've reported as being a problem. Soon, it will probably be unable to select any gears at all, so it's worth fixing ;)

-Alex
 
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I had looked at the hydraulic pressure but wasn't sure what was normal. Seemed to fluctuate between 30 and 60 bar but the link you gave suggested it should be 45-55 so it looks like the accumulator. Will contact Mal. Thanks.
 
I sympathise with the diagnosis difficulty. It definitely helps to poke around with MultiECUScan on a car where everything's working normally, so that you have something to compare against when trying to identify a problem; for other examples, lambda sensor outputs, air mass quantity. Otherwise it is hard to know what's normal and what's faulty... and even a straightforward-sounding fault code can have a hidden meaning. Thanks for drawing that particular fault code to my attention, as I hadn't seen it before or thought about its cause.

-Alex
 
I think it is the accumulator. Had this kind of error with a friend of mine and i noticed more frequent running of the selespeed pump, also pressure spikes when we viewed the oil pressure. After replacing the accumulator all was normal :)
 
I have replaced the accumulator and car now back to normal.:)

The elearn instructions encourage excess dismantling at times and I ignored the one to remove engine ECU and I found removing the air tube then unplugging pump made getting to plug much easier.

The instructions just say to remove accumulator but there is not much room for a spanner. So I bought a 27mm ring spanner. Bent the open end 90deg with a gas torch then ground a 3mm chamfer on the upper side of the jaws so it sat snug up against the accumulator and the jaws did not extend below the hex on the accumulator (a custom crows foot spanner) A bar through the ring and the accumulator was off in no time at all.:cool:
 
If anyone wants to borrow it they are welcome. Hopefully I will not need it again soon.

Helli mate just wondered if you still have that tool you made to remove the accumulator..is it poss to get a use from it.. thanks
 
I have replaced the accumulator and car now back to normal.:)

The elearn instructions encourage excess dismantling at times and I ignored the one to remove engine ECU and I found removing the air tube then unplugging pump made getting to plug much easier.

Hi, this post is very useful since I have the same problem with the err msg 'P1769 Pump Driving Relay Stuck' on my Fiat Grande Punto '09. I live in Barbados and mechanics here are not too familiar with Fiat cars. Did you find instructions on-line to locate and replace the actuator? You mention 'elearn instructions'. Where can these be found? Thank you.
 
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