Polo 9N Steering Wheel Removed --

Hello everyone,

I have a problem with my Polo 9N 1.9 TDI, manufactured in 2002. My power steering has been acting up recently, with the power steering motor simply shutting off. This is easily noticeable by the active power steering light in the dashboard and the extremely stiff steering. What's interesting is that the power steering either works completely or not at all. Unfortunately, the problem has been developing gradually. It started in January when the power steering light remained on after starting the engine. The problem could simply be fixed by re-igniting it.
Now, even after the engine starts, the light remains on and the power steering is disabled. After I had read out the error codes, I received error messages from the on-board network, brakes, airbag, and power steering, which pointed to a defective battery. So, I tested the battery with a test device under load, and it was indeed no longer usable (7 years old). After a battery replacement, the problem still persists, and the following error is present in the memory:

Address 44: Steering Aid Label File: RKS\6Q0-423-156.lbl
Part Number: 6Q0 423 156 L
Part: Steering Assist Device KYO V910
Encoding: 00120
Plant Number: WSC 31414

1 Error found:
00566 - Support for the Lenkhilfe Operation
27-10 - Unlikely signal


It's also interesting that when the turn signal light fails, the turn signal still functions normally. This happens sometimes, so it's sporadic. However, it then fails after a maximum of 5 minutes while driving. I have also checked the control unit's data blocks.

The rotational speed of the steering angle sensor is, in my opinion, plausible when the steering system is malfunctioning. Unfortunately, I haven't been able to log any data when the steering system is functioning correctly. The voltages at terminal 30 fluctuate between 12.2-12.94V when the motor is not active; when the motor starts, it is close to 10V, and when the motor is running, the voltage is between 13.9 and 14.2V.
While the engine is running, the pump motor status (Block 3) is surprisingly "on", while Block 1 is "off", the sensor "G250" is "yes", but there is no current flowing (pump motor current).
Also interessant ist auch, dass, wenn der Motor startet, die Soll-Drehzahl des Pumpenmotors etwa 5 Sekunden auf 1664 /min ansteigt, während die Ist-Drehzahl bei 0 /min bleibt, und die Soll-Drehzahl nach den 5 Sekunden wieder auf 0 sinkt.

I have read that hairline cracks in the seat fasteners on the battery box could be the cause. Is this really realistic? Should I replace the rotary sensor first? I'm still a bit hesitant about the €500 cost for the new steering system... Does anyone have any ideas???

Thank you in advance.
Maximilian

demadmax wrote:

I have read that hairline cracks in the battery box's securing bolts could be the cause. Is this really realistic?

It's at least a relatively + inexpensive source of error, which prevents you from testing it?

Furthermore, I would carefully examine the connectors on the pump module (behind the driver-side spoiler grille):
Bends/Breaks due to too short cable lengths?
Are all the seals present in the connectors?
Corrosion signs on the contact surfaces?

Repeatedly loosening and tightening to remove any remaining corrosion layers is not harmful. Subsequently, applying a single drop of acid-free oil to each contact point protects against new corrosion

But don't soak the connectors in oil, because then the seals will swell and, in the long run, will actually allow water + dirt to get to the contacts.

I'm trying, but I don't know if a small crack in a wire will affect a current of 10 or 50A. I already removed the fuse, but I didn't see anything. According to polo9n.info, it should be the 3rd. Ensuring the safety of flax by grounding it on the left (according to Polo9n.info, 80A, but mine is 50A ??)?
But thank you for the tips, I will try it. I've already checked to see if I can see the plug, but I think even if I remove the battery compartment, I won't be able to get to it.

demadmax wrote:

But I don't know if a small crack in a wire will be affected by 10 or 50A current.

The wire cross-section is all the more important the higher the current is.
If a hair crack runs perpendicular to the direction of current flow, a corresponding small cross-section remains in the resulting bottleneck, meaning that at high currents, the voltage behind it becomes too great, and the device may start to malfunction

Hi demadmax,
If it comes to the point where you need to replace the electrohydraulic power steering pump, I might want your oil reservoir. If your pump is a SIM KOYO and the oil reservoir has the following number: 6Q0 423 371 B, then it would fit. Mine was shattered into several pieces due to a crash. PN also.

Best regards,
Ronny

Hello again,

I had the car on the stage on Friday, and after I had demonstrated the air filter, battery box, wheel arches, etc., and still only managed to connect with a moving metal hose with a camera to the very poorly placed connectors on the pump, I realized that in fact, all the cables were actually in order. After I re-checked my diagnostic tool and inspected the oil in the servo reservoir and steering gear, the error should also, according to my MBBn and the Rosstech wiki, be located in the servo pump.
I'm going to replace the servo pump. Does anyone happen to know what this costs at VW?

Greetings
Maximilian

Servo pump
TRW 6Q0 423 155 AE approx. 550€
SMI Koyo 6Q0 423 162 X approx. 500€ (Replacement)
EDIT: Market conditions as of the end of 2007

@ RedR32:
The oil tank with the "B" designation that you are looking for was only installed in Fox, Polo, and Derby models starting in 2005. The vehicle belonging to the person who started the thread is from 2002. Even if it's an SMI Koyo and not a TRW, the ending is A.

Greetings
Guste

Hello,

@ Guste100:
Right. My servo pump must have already been replaced. I only just bought the Seat Ibiza (ATD) from 2004. The date on the pump mount is 07/06. The complete pump is available, but the A and B containers are no longer available. Now I welded a steel container myself. Ugh, that was quite a lot of work. Luckily, the pump works perfectly after the accident. Okay then, good night.

Best regards,
Ronny

@guste100
Thank you for the information.

Hello, I just wanted to add a few comments about this issue. The problem with the servo is well-known in the Polo 9N, and it occurs when the voltage from the battery or generator falls below a certain threshold. It's a strange issue, but that's how it works. I personally had two such cases in my workshop. In one case, the pump was definitely faulty, but VW refused to cover it. However, after writing a letter directly to VW and demanding 100% for parts and 70% for labor, they finally agreed. In the other case, the generator voltage was around 11.3V, which was too low for the pump to function.
Problem with the Polo 9N, underneath the battery compartment, difficult to identify: there is a connector with a blue cable that intermittently disconnects. If this is the case, the generator may not charge or charge very poorly, and the threshold value may drop, and the steering will no longer function. Fix the connector with a repair cable or bypass the connector with waterproof solder connectors, and the problem is solved.

I hope I was able to help. Please feel free to contact me at 0151-56537187 if you have any questions.

Best regards, FTS Iaquinta