P17737B Active Hydraulic circuit Flow/Pressure - Low fluid level

The above is the diagnostic code after having my pump replace by my son in laws mate, who was the only person I could find to have a go at replacing it for me,(apart from super over priced main dealer, 2008 its only got 22000 miles. went wrong after battery became low one winter and kept blowing fuses, pump was replaced a couple of months ago, worked fine on day replacement, took it for a 20 min run. next day struggled to get gear then stopped, just stuck in neutral, unfortunately can't get the guy back. looking for tec as might be something straight forward like bleeding the system but just can't find any info. cheers

Dualogic transmission fluid initial fill must be performed in two steps:

- fill to the top
- open driver's door: the pump will prime and partially empty the reservoir
- adjust the fluid level to the MAX line: done !

If initial fill wasn't done like this, there is a possibility that fluid level will get low enough so the pump can't reach the correct pressure ...

BRs, Bernie

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I've tried the opening the door and let the pump work, nothing happened.

but just had the diagnostics on it, trying to bleed it that way, saying hydraulic pressure must be greater then 42bar, so not letting me go any further.

if your got any Ideas. cheers

Is the pump rotating at all when you open driver's door ?

The pump is driven by a relay and fuse protected, the relay itself being driven by the Dualogic controler …
Those pumps are well known for bad internal insulation that causes the fuse to blow, that would be my first check.

BRs, Bernie

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Hi Bernie,

Checked relay (R8) and fuses (83), tested as shown in youtube vid, all clicking and omhs as shown. fuse ok

still nothing. not sure on just opening drivers door as I live near a busy road and can't really hear that well, not sure how much noise pump should make as never noticed it when it was fully working.

is there a way of testing pump, incase the new one has blown for some reason. one of the hardest systems to find details.

cheers

stu

The pumps are relatively LOUD in.my experience.

To the point where I would gain entry through passenger door.. so I didnt make it run again!!

I must be going deaf as I didn't hear it before it stopped working

You can direct feed the pump (electro bomba) with positive from the battery, but before doing that you'd better ohm it to check for continuity (a few ohms I guess) or short to ground …

BRs, Bernie

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I'll check it out tomorrow, as need to move the car from where it is, on my first photos I added, theres a red and black wire, guessing red if live and the black is negative, if I take direct feed to red (once ive checked the ohms) would that be the only feed, or would I need to do the negative or is it likely to be earth via the body of the car.

cheers Bernie


stu

Hi Stu,

sorry for late reply, you need to feed both polarities as the pump doesn't seem to be grounded by itself. And your color coding is right: red to positive and black to ground …

Expect some sparks since it's a quite big motor and it'll draw huge current (fused protected @30A)

BRs, Bernie

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Looks like pump fcked, put power supply on pump motor, pics to show power and voltage going to it, pump was only on for 12hrs before it failed, was a new one off ebay, notice it had a 60amp fuse and not 30amp, would that cause the pump to blow? as not sure what to do, as don't want to buy another and that blows. as it worked well before problem started, cold snap and poor battery.

I didn't change the pump myself, was my son-in-law mate, have you got details of changing the pump?

cheers

stu

Hi Stu,

the pump itself is probably not at fault, but the motor is.
In the initial post you pictured a new complete assy, which most of the time is not needed as you only got to replace the electric part of it, for less money …

Replacement is pretty much straight forward:

- remove the guard/shielding
- disconnect pipes
- unscrew brackets
- remove pump & bracket
- remove pump from bracket
- remove motor from assembly
- install new motor on pump
- re-fitt on bracket
- etc.

NOTE: the motor is brush type, so there is a chance that the coil is not open (you haven't pictured ohming it BTW !!) but one of the brush is not contacting anymore. You can open the motor using some persuasion, vise, plyers, crow-bar, sledge-hammer … and inspect it before buying a new one, it's not rocket science and you might be able to fix it and improve its poor insulation (you'll see by yourself what I mean), then get proud and self-satisfied

BRs, Bernie

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I've checked old pump motor, as in photo, not sure if testing correctly, getting under motor later to check that pump.

This is the ohms from pump on the car. Not sure what it should be. Am I missing something, like relay ok, and fuse is ok, wondering if there's a 3rd or 4th relay or fuse linking back. Cheers Stu

Hi Stu,

both ohmed values are WAY too high !

Old pump shows 610 Ω which would allow (I=U/R) 12/610 less than 20 mA to go thru.
Installed pump shows even more resistance (5K), which would allow as low as 2,4 mA current flowing through the motor = Nothing in BOTH cases !!

MOST probably bad contact @ brush(es) level, otherwise the resistance would be infinite (open circuit). I hope you still got the old pump (motor) so you can experiment on it before trying with the new(er) one . Finally you might be able to restore both and keep one as spare …

BRs, Bernie

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Thanks Bernie for advice, I've given up on her for a moment, as not sure whats causing things to go faulty, as the newer one shouldn't have gone wrong less then a day. not sure on resistance ohms side either, no sure what open circuit should give me and never done bushes before.

there is once thing I haven't asked what fluid is used in the selespeed system, as think it had the fiat gearbox oil put in it.

cheers stu

stusvans said:

Thanks Bernie for advice, I've given up on her for a moment, as not sure whats causing things to go faulty, as the newer one shouldn't have gone wrong less then a day. not sure on resistance ohms side either, no sure what open circuit should give me and never done bushes before.

there is once thing I haven't asked what fluid is used in the selespeed system, as think it had the fiat gearbox oil put in it.

cheers stu

Click to expand...

Gearbox oil in the dulalogic unit?
If so that will 100% be the cause of the failure the unit runs on nothing like gearbox oil
It should be CS speed fluid

Thanks Chris for your reply, dawned on me, son-in-law mate topped it up with fiat gearbox oil Tutela 75w-85. but still can't work out why the pump not working at all, as only drove it for 15 minutes after it was fitted, worked fine, it was the next morning it wouldn't get gears again. cheers stu

WHY haven't said that before ???

The GB oil is WAY thicker than the hydraulic fluid !! Once it had been mixed and sucked-in, the pump and therefore the electric motor have had a hard time, and gave-up …

I'm a afraid you'll need another one and drain out the whole dualogic system (including pressure reservoir). Anyway, at this stage I would open the motor and see what went wrong (probably overheating) …

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

Hi Bernie

I had it fitted by son-in-laws mate, I'm no mechanic, he topped it off after he fitted it with the tutela transmission oil, only while trying to research further, I saw their was different oils being used, I thought the tutela was used for complete system.

would 15 mins of running the pump with transmission oil kill it, as I was trying to read up on why it won't get the pressure up, which I could understand is there's two fluids in the system.

The first pump, if I do try and strip it down where would I get the bushes from? as never done anything like that apart from many years ago on a drill.

cheers

stu