'09 Fabia BXW engine stalling while idling caused by electronics..?

[quattro84]

Hi there!

I am getting big problems with my Fabia II with 133k on the clock. It's the 1.4 BXW engine.
While entering a round-about I had my power steering completely fail on me, never had any issues before. After a key cycle it worked again and did continue to work for a while.
Since a week it has became worse, it is now fully killing of the engine! During this event I get the long beeeeeep from the cluster, cluster light drops, display stops, airbag light comes on, and after a sec it all works, and occasionally the PAS light stays orange but does work. (VCDS memory shows 01288, see below)
It occurs only when idling and manouvering around without at low revs. At higher revs I did see the illumination "blink" while driving, and lights dim when driving with lights on.

In the mean while I have replaced the voltage regulator, getting 14.4V on no load, 13.7/50A at high load.
Then I've replaced the battery, removed earth straps at the engine and at the chassis to check/clean, checked almost all of the relevant fuses, and connectors on the PAS pump (this is the only module that fails besides the engine stalling)

I've borrowed a VCDS and logged the active faults, the cruise control does not work (switch stopped working) and the others clear. Only the 1288 reappears while driving at the time of (or just before) stalling the engine.

So what to do: Can the PAS pump kill off the electrics? Or is it the cruise control stalk? Or is it something else like the Voltage control module?

Pump wiring I have checked and seems OK and clean. Earth point resistance is 0.0 Ohms compared to battery earth point.
I have coded the pump to least resistance but that does not make any difference. I cannot believe it is the pump load current causing this by itself.

I made log while driving, it is only 1Hz but is does show the voltage drop for 044 module while running to 11V. Connection also drops causing the VCDS log to stop (or engine stall, which causes the same)

Please advise, I am lost...
 

Mileage: 133190km-82760mi   Repair Order: 

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

Chassis Type: 5J (5J - Skoda Fabia (2007 > 2010))
Scan: 01 02 03 08 09 15 16 17 19 25 37 44 46 55 56 76 77
 
VIN: TMBBC65J8A3124179   Mileage: 133190km-82760miles
-------------------------------------------------------------------------------
Address 01: Engine        Labels: 03C-906-024-BXW.lbl
   Part No SW: 03C 906 024 B    HW: 03C 906 024 F
   Component:  MARELLI 4HV      G 4115  
   Revision: --H11---    Serial number: SKZ7Z0I5633662
   Coding: 0000071
   Shop #: WSC 13765 790 00000
   VCID: 1D3A398DC7CD42A9E2-5102

1 Fault Found:
17977 - Cruise Control Switch (E45) 
            P1569 - 000 - Implausible Signal
             Freeze Frame:
                    Fault Status: 01110000
                    Fault Priority: 1
                    Fault Frequency: 0
                    Reset counter: 0
                    Mileage: 0 km
                    Time Indication: 0
                    Date: 2000.01.01
                    Time: 00:00:00

Readiness: 0110 0101

-------------------------------------------------------------------------------
Address 03: ABS Brakes        Labels: 6R0-907-37x-ESP80.lbl
   Part No SW: 6R0 907 379 E    HW: 6R0 907 379 N
   Component: ESP 8.0 front   H06 0002  
   Revision: 00000000    Serial number: 00000000000000
   Coding: 0002359
   Shop #: WSC 13765 790 00000
   VCID: 4084A0F910FF4F41A9-5102

1 Fault Found:
00532 - Supply Voltage B+ 
            002 - Lower Limit Exceeded - Intermittent

 

-------------------------------------------------------------------------------
Address 44: Steering Assist        Labels: 6Q0-423-156.clb
   Part No: 6R0 423 156 A
   Component: LenkhilfeTRW        V275  
   Coding: 10120
   Shop #: WSC 13765  
   VCID: 2E58EE41EA6BC9314B-5102

1 Fault Found:
01288 - Terminal 30; Steering Assist 
            07-10 - Signal too Low - Intermittent

[sepulchrave]

Battery and charging system is not coping with the electrical load.

 

Start measuring voltages.

[quattro84]

17 minutes ago, sepulchrave said:

Battery and charging system is not coping with the electrical load.

 

Start measuring voltages.

And what precisely? Not sure where to start.

I've logged the 44 - steering group, it reads 14.4V at idle and keeps high while I am steering like a mad man. I've logged up to 40A. It is all of the sudden all modules seem to see the voltage drop. I am wondering if my alternator (changed regulator only, rest not checked) is having issues. Both connectors I've checked and cleaned, voltage is 4.5V/11.3V at key on.

[sepulchrave]

What does the battery read before and after starting?

[quattro84]

1 minute ago, sepulchrave said:

What does the battery read before and after starting?

On the old and new it's 12.5-6V and 14.4V while running measured on the battery. Modules read 14.3 as well. Like said, with full lights/fan/aircon/blower on I managed to pull 50 Amps and it still read 13.7V.

[KenONeill]

4 minutes ago, quattro84 said:

On the old and new it's 12.5-6V and 14.4V while running measured on the battery. Modules read 14.3 as well. Like said, with full lights/fan/aircon/blower on I managed to pull 50 Amps and it still read 13.7V.

None of which proves you don't have a blow under load on the steering strip fuse on the battery top.

[quattro84]

11 minutes ago, KenONeill said:

None of which proves you don't have a blow under load on the steering strip fuse on the battery top.

I have checked the connection of the wire to the strip. It's clean. Checked resistance of the fuse and seems OK. Indeed, not checked under load. What can I try then, swap Fuse 5 with 6..? Do these blow often?

[quattro84]

Any clues how module J519 - Vehicle voltage control unit gets it power? Want to check which fuse and cable it's using, not finding it in kolhosniki.ru/elsaonline

[sepulchrave]

It seems like your alternator might be playing up, can you rig up a voltmeter to the the cigar lighter socket and tape it somewhere you can see it when the problem happens.

[quattro84]

That is what I am pondering as well. I have logged the 44 group signals, and it shows it does drop while Idling and being high during the drive. At the end of the log I am parked/rolling in gear at 800rpm heavily steering to get it to stall. That is when it ends my log with stalling the engine.

 

I am not sure how flat the clamp 30/15 voltage would be with a perfect altenator. Might pull it off again and have it fully checked, might be it has an issue.

[KenONeill]

47 minutes ago, quattro84 said:

I have checked the connection of the wire to the strip. It's clean. Checked resistance of the fuse and seems OK. Indeed, not checked under load. What can I try then, swap Fuse 5 with 6..? Do these blow often?

That would work; the usual way of testing a fuse for blow under load is to fit a known good one and see if the fault goes away.

[J.R.]

2 hours ago, KenONeill said:

None of which proves you don't have a blow under load on the steering strip fuse on the battery top.

 

Fuses blow or they don't, they are not a resettable circuit breaker.

 

Maybe you mean a fractured fuse that will pass a small current but not the full load? that would give the opposite effect to the volt drop the OP is experiencing which crashes the modules and causes the engine to stall.

 

I concur with looking for an alternator or battery fault, my suggestion based on my first reading of the symptoms is an insulation breakdown in the power steering actuator windings that shorts momentarily in a certain position under certain conditions and drops the voltage enough to crash the modules but not long enough to blow the fuse.

 

It is possible that the fault may have manifested before and someone has fitted a higher rated fuse. In general a fuse will take  longer to blow than a module will to hiccup from a low supply voltage.

Edited 15 September, 2022 by J.R.

[sepulchrave]

It's a brushless AC motor so the coils are stationary, I'm convinced it's the alternator voltage breaking down under load.

[nta16]

3 hours ago, sepulchrave said:

Battery and charging system is not coping with the electrical load.

 

Start measuring voltages.

 

You had me at "Battery and charging system", Jerry.  :swoon and tears:

[Breezy_Pete]

12 hours ago, quattro84 said:

Any clues how module J519 - Vehicle voltage control unit gets it power? Want to check which fuse and cable it's using, not finding it in kolhosniki.ru/elsaonline

 

Not sure it'll be relevant, but as far as I can see these are the various power feeds to the circuitboard that aren't just straight in and out of a relay dedicated to that item, e.g. wipers:

 

a permanent 12V power feed from cabin fuse 22 via the red-yellow wire at XP2/1,

 

a 'key in ignition' (T86s) switched feed from fuse 19, into XS4/2,

an ignition on (T75) feed into XS4/11,

an ignition on (T15) straight from ignition switch to XS4/12

and another permanent 12V feed from engine bay fuse 11 into XS4/5.

 

 

It almost looks like a more global electrical problem to me, like an ignition switch 'iffyness'.

 

[quattro84]

Alternator has been removed to be checked. Bench tested 3 times, came out OK.

 

Wondering how to proceed now, how do I verify the signal from the ignition switch?

[Breezy_Pete]

I'd whack another on there if it were me just to rule it in/out, only a few quid.

Whereabouts are you?

[quattro84]

The Netherlands. I'll be calling my local ex-Skoda garage next to ask if they have any idea on this topic. They still service loads on Skoda's and were able to help me before.

[Breezy_Pete]

Please let us know when you find/solve the problem. 

[quattro84]

Other theory: can the PAS pump controller internally short causing the other modules from that Kl30/15 feed to go offline? 

 

It only stalls while idling or motoring in gear while steering (so activated pump, sensor sensing motion)

[Breezy_Pete]

The ignition switched (Kl15)  supply to the pump module is from a 5 amp fuse (cabin fuse 16) so I think that would blow if there was a short inside.  The Kl30 fuse is the strip fuse in the battery fuseholder, but a problem with that wouldn't interfere with any other systems, like the engine as far as I can see.

 

See if you can increase the frequency of failure by adding a Kl15 load, say by switching on the rear wiper.

Edit, no, that won't do, it seems to be fed from the 75x rail, not Kl15.

 

Does the car have heated seats? That looks to be fed from Kl15.

 

 

Edited 16 September, 2022 by Breezy_Pete

[quattro84]

I was just wondering if it could have linked it's feeds internally in the pump controller causing the circuitry to have the voltage drop.

 

Adding other loads like lights, fan, blower does seem to make it stall quicker. And, just before the stall steering orange warning comes on (Think this is the 01288 MIL) but continues to operate. Only if you give it some more time/drive it will cause other modules to drop off. It will not recover within the same key cycle. After the stall it all works again. To me it sounds like some circuit needs load to heat up or something to make it fail...

[quattro84]

2 hours ago, Breezy_Pete said:

 

2 hours ago, Breezy_Pete said:

Does the car have heated seats? That looks to be fed from Kl15.

 

 

No it doesn't.

[quattro84]

Replaced the steering pump by a rebuild one. Issue still occurs. 

 

I am losing my mind. I am going to swap out the alternator even though the current one was tested. After a test drive of 3 miles (and setting the same codes while pulling op the driveway at idle)  the alternator was pretty hot. 

 

Whilst swapping the pump I've checked all wiring and connectors --> fine. Checked the wire loom under those plastic covers beneath the battery, no trouble found.

[sepulchrave]

1 hour ago, quattro84 said:

Replaced the steering pump by a rebuild one. Issue still occurs. 

 

I am losing my mind. I am going to swap out the alternator even though the current one was tested. After a test drive of 3 miles (and setting the same codes while pulling op the driveway at idle)  the alternator was pretty hot. 

 

Whilst swapping the pump I've checked all wiring and connectors --> fine. Checked the wire loom under those plastic covers beneath the battery, no trouble found.

 

I may have mentioned the alternator before, once or twice, it's breaking down under load which can't easily be tested.