Steering rack upgrade from PR-1N2 to PR-1N4

[Jay-Jay]

Here it is:
ESP8.2i
J104
HW: 6R0907379AF H05
SW: 6R0907379AF 0005
Long coding:
210248E3437200BA842912E9C2D800421700

[iichel]

Hm, that looks ok to me. You could try 210248E3417200BA842912E982D800421700 to remove the sports package option but i doubt it will make a difference.

[ciclo]

I don't know if it's related and I don't know if I already mentioned it here or elsewhere, but when the front bushings were changed in an official workshop on our ex-9N3, the subframe was removed to do it more 'easily' (not indicated in the manuals to do this job), and then the wheels squeaked on every corner at just 20 km/h... they had not aligned the subframe.

[Jay-Jay]

Hm, that looks ok to me. You could try 210248E3417200BA842912E982D800421700 to remove the sports package option but i doubt it will make a difference.

I've just tried the coding you suggested, but the problem is still there.
Just out of curiosity: what does the sport package ABS coding mean? Does it affect somehow the way ESC works?

Btw: this morning I asked a mechanic friend to take a test drive together with me.
We test drove the car for about 2 hours over all the roads and turns where I was sure to replicate the ESP problem.
At first, he said it feels like an electronical problem. So, while he was driving I monitored wheel speed sensor and G85, G200 and G202 sensor values, but I didn't noticed any strange value, even when the ESP kicked-in abruptly.
Like me, he also noticed the problem is much more present when turning on the right than on the left.
He also noticed that there is wheel rubbing only on the front left wheel when taking turns on the right. It seems like there is more body rolling and suspension compression on the front left of the car. As I already said, I replaced almost everything: the struts and all the wishbones bushings are new, so they can't be the cause of that.
So, after a while, he asked to bring the car to my garage to have a quick look at the front left wheel, which seems where the problem comes from.
We lifted the car and the front left wheel has literally zero play.
He excluded any kind of mechanical problem related to the steering rack and to the ball joint.
Then, with the car lifted only on the left side, he asked me to turn the steering wheel and to quickly move it by little movements on the left and on the right, while looking inside the wheel arc to the suspension components. What he saw is that the antiroll bar seems to not only rotate up and down, but also to steangely move in a diagonal way, like if the rubber bushings have a bit of play, despite the fact they don't make any noise on the road.
So, in the end, he suggested me to precautionally replace them, preferrable with poly bushes and to test again the car.

I don't know if it's related and I don't know if I already mentioned it here or elsewhere, but when the front bushings were changed in an official workshop on our ex-9N3, the subframe was removed to do it more 'easily' (not indicated in the manuals to do this job), and then the wheels squeaked on every corner at just 20 km/h... they had not aligned the subframe.

When I did the steering rack replacement job, I centered the subframe with the proper VW centering pins... This is why I can't understand what is going on.
1 week after I brought the car to the wheel alligbmebt workshop and the measured values were pretty good. I remember there was just a slight difference of 0,4° in caster between the front left and the front right wheel. Camber was almost identical.
More than 1 month ago, I also installed front subframe rigid collars, which not only center the subframe, but also make it more rigid and eliminate the play the bolts have inside the subframe holes.
I'm really getting crazy. All seems ok, but it is definetely not when on the road.

[iichel]

i'm guessing the steering angle of the wheels is different between what the ESP expects based on steering angle sensor

so G85 angle of i.e. 180 degrees would be a certain movement in the rack, that results in the movement of the steering arm by 1 cm. then the wheel makes an 10 degree angle. wheel rotation difference shows, lateral acceleration has a value.

with the 1N1 it might be 1 cm of steering arm, with 1N4 it's maybe 0.8cm. I guess this is where the ESP says 'something ain't right' because the values don't show as expected and tolerances are violated

it probably is a coding thing, that's why i suggested sports mode in ESP coding. i'm sorry it didn't help.

[Jay-Jay]

That would make sense.
You don't have to be sorry. I'm graetful to you for your help.
So I'd need to understand what I have to modify in the ABS coding.
If some other ideas come to your mind, I'm open to make new tries.
Honestly, I wouldn't want to find myself obligated to put back my old PR-1N2 steering rack.

[iichel]

could you post an adapmap of your abs controller please?

[Jay-Jay]

Here it is:

Code: Select all

	SW:6R0-907-379-AF   HW:6R0-907-379-AF ---  ABS Brakes --- SA: 40168
	Component:ESP8.2i front H05 0005, Coding:210248E3417200BA842912E982D800421700
	Sunday,09,June,2024,17:03:12:00009
	VCDS Version: Release 21.9.0 (x64)  Data version: 20210903 DS330.0
	VCID: 020B3F0F990F189957-8056
	
Channel		Field 1	Field 2	Field 3	Field 4	
1	0	Adaptation	Tire Pressure	Enabled	N/A	
2		ERROR:	Channel 02	Not	Available	
3		ERROR:	Channel 03	Not	Available	
4		ERROR:	Channel 04	Not	Available	
5		ERROR:	Channel 05	Not	Available	
6		ERROR:	Channel 06	Not	Available	
7		ERROR:	Security	access	required	
8		ERROR:	Channel 08	Not	Available	
9	2	Value	large	N/A	N/A	
10		ERROR:	Security	access	required	
11		ERROR:	Channel 11	Not	Available	
12		ERROR:	Channel 12	Not	Available	
13		ERROR:	Channel 13	Not	Available	
14		ERROR:	Channel 14	Not	Available	
15		ERROR:	Channel 15	Not	Available	
16		ERROR:	Channel 16	Not	Available	
17		ERROR:	Channel 17	Not	Available	
18		ERROR:	Channel 18	Not	Available	
19		ERROR:	Channel 19	Not	Available	
20		ERROR:	Channel 20	Not	Available	
21	1	Value	center	N/A	N/A	
22		ERROR:	Channel 22	Not	Available	
23		ERROR:	Channel 23	Not	Available	
24		ERROR:	Channel 24	Not	Available	
25		ERROR:	Channel 25	Not	Available	
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32		ERROR:	Channel 32	Not	Available	
33		ERROR:	Channel 33	Not	Available	
34		ERROR:	Channel 34	Not	Available	
35	1	Function	ON	N/A	N/A	
36	2	Value	Strong	N/A	N/A	
37		ERROR:	Channel 37	Not	Available	
38		ERROR:	Channel 38	Not	Available	
39		ERROR:	Channel 39	Not	Available	
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50		ERROR:	Channel 50	Not	Available	
51	1	Function	Enabled	N/A	N/A	
52		ERROR:	Channel 52	Not	Available	
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54		ERROR:	Channel 54	Not	Available	
55		ERROR:	Channel 55	Not	Available	
56		ERROR:	Channel 56	Not	Available	
57		ERROR:	Channel 57	Not	Available	
58	1	Value	center	N/A	N/A	
59		ERROR:	Channel 59	Not	Available	
60		ERROR:	Channel 60	Not	Available	
61		ERROR:	Channel 61	Not	Available	
62		ERROR:	Channel 62	Not	Available	
63		ERROR:	Channel 63	Not	Available	
64		ERROR:	Channel 64	Not	Available	
65		ERROR:	Channel 65	Not	Available	
66		ERROR:	Channel 66	Not	Available	
67		ERROR:	Channel 67	Not	Available	
68		ERROR:	Channel 68	Not	Available	
69		ERROR:	Channel 69	Not	Available	
70		ERROR:	Channel 70	Not	Available	
71		ERROR:	Channel 71	Not	Available	
72		ERROR:	Channel 72	Not	Available	
73	1	Function	ON	N/A	N/A	
74		ERROR:	Channel 74	Not	Available	
75		ERROR:	Channel 75	Not	Available	
76		ERROR:	Channel 76	Not	Available	
77		ERROR:	Channel 77	Not	Available	
78		ERROR:	Channel 78	Not	Available	
79		ERROR:	Channel 79	Not	Available	
80		ERROR:	Security	access	required	
81		ERROR:	Channel 81	Not	Available	
82		ERROR:	Channel 82	Not	Available	
83		ERROR:	Channel 83	Not	Available	
84		ERROR:	Channel 84	Not	Available	
85		ERROR:	Channel 85	Not	Available	
86		ERROR:	Channel 86	Not	Available	
87		ERROR:	Channel 87	Not	Available	
88	1	Function	ON	N/A	N/A		
89		ERROR:	Security	access	required	
90		ERROR:	Security	access	required	
91		ERROR:	Channel 91	Not	Available	
92		ERROR:	Channel 92	Not	Available	
93		ERROR:	Channel 93	Not	Available	
94		ERROR:	Channel 94	Not	Available	
95		ERROR:	Channel 95	Not	Available	
96		ERROR:	Channel 96	Not	Available	
97		ERROR:	Channel 97	Not	Available	
98		ERROR:	Channel 98	Not	Available	
99	0	Value	 	N/A	N/A	
100		ERROR:	Channel 100	Not	Available	
101		ERROR:	Channel 101	Not	Available	
102		ERROR:	Channel 102	Not	Available	
103		ERROR:	Channel 103	Not	Available	
104		ERROR:	Channel 104	Not	Available	
105		ERROR:	Channel 105	Not	Available	
106		ERROR:	Channel 106	Not	Available	
107		ERROR:	Channel 107	Not	Available	
108		ERROR:	Channel 108	Not	Available	
109		ERROR:	Channel 109	Not	Available	
110		ERROR:	Channel 110	Not	Available	
111		ERROR:	Channel 111	Not	Available	
112		ERROR:	Channel 112	Not	Available	
113		ERROR:	Channel 113	Not	Available	
114		ERROR:	Channel 114	Not	Available	
115		ERROR:	Channel 115	Not	Available	
116		ERROR:	Channel 116	Not	Available	
117		ERROR:	Channel 117	Not	Available	
118		ERROR:	Channel 118	Not	Available	
119		ERROR:	Channel 119	Not	Available	
120		ERROR:	Channel 120	Not	Available	
121		ERROR:	Channel 121	Not	Available	
122		ERROR:	Channel 122	Not	Available	
123		ERROR:	Channel 123	Not	Available	
124		ERROR:	Channel 124	Not	Available	
125		ERROR:	Channel 125	Not	Available	
126		ERROR:	Channel 126	Not	Available	
127		ERROR:	Channel 127	Not	Available	
128		ERROR:	Channel 128	Not	Available	
129		ERROR:	Channel 129	Not	Available	
130		ERROR:	Channel 130	Not	Available	
131		ERROR:	Channel 131	Not	Available	
132		ERROR:	Channel 132	Not	Available	
133		ERROR:	Channel 133	Not	Available	
134		ERROR:	Channel 134	Not	Available	
135		ERROR:	Channel 135	Not	Available	
136		ERROR:	Channel 136	Not	Available	
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138		ERROR:	Channel 138	Not	Available	
139		ERROR:	Channel 139	Not	Available	
140		ERROR:	Channel 140	Not	Available	
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142		ERROR:	Channel 142	Not	Available	
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144		ERROR:	Channel 144	Not	Available	
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251		ERROR:	Channel 251	Not	Available	
252		ERROR:	Channel 252	Not	Available	
253		ERROR:	Channel 253	Not	Available	
254		ERROR:	Channel 254	Not	Available	
255		ERROR:	Channel 255	Not	Available	

At this point, I wonder what's the function of the last digit in the Steering coding ("0" for PR-1N2 and "1" for PR-1N4). I thought it makes the ABS unit knows what kind of steering rack is installed, but maybe it only affects the steering fluid pressure and the steering feeling.

[Jay-Jay]

Well, while waiting for the new front antiroll bar poly bushes to arrive to me and hoping for a ABS Unit coding solution, tonight I casually did some Google searches in english, which in the end opened my mind.
It seems like upgrading to a quick steering rack was a popular upgrade, especially on Golf mk4 platform. People used to install Golf 4 R32 or Audi TT mk1 rack, which is shorter than the one factory installed on normal mk4 platfrom's cars.
Not all the cars from that generation had ESP factory installed. Some of them only had ASR.
Well, the owners who installed the quick steering rack on their cars with ESP, immediately experienced my same identical problem!!!
Simply Google "vw quick rack esp problem" and you'll find many forums talking about this.
ABS unit installed on those cars were much less complex (software speaking) than ABS unit installed on my Polo 6R. Despite that, I haven't found anywhere the trace of somebody who has found a defintive solution to this problem.
It seems like the only possible solutions are two:
- completely disable the ESP (wich is impossible on Bosch 8.2i ABS Unit and I would never always drive a car without ESP);
- put back a PR-1N2 steering rack.

My car has a tons of suspension upgrades. Bilstein B14 coilovers, poly bushes, Polo R WRC front sway bar, Whiteline rear anti-roll bar, GTI rear axle beam.
In the case iichel or some other guru would not appear with a magical ABS coding or other solutions (ie. replacing the ABS unit with a GTI one), after what I discovered I think I'll be ok with putting back the PR-1N2 steering rack.
I use my Polo as a daily car and I can't keep it like this.
Last day I was driving with a friend sitted on the passenger seat and suddenly while taking a turn on the right, the ESP kicked-in very strongly. It scared the ass out of him and it made me feel extremely embarassed. Luckily I know my car and all the mods I did make it handle tremendously better compared to how it did out of factory, so I wouldn't say this ESP problem can be considered a safety problem in my case. But I just can't keep it like this.
And it's a pity, because the steering feel is amazing: quick, precise, a bit heavier and more connected to the wheels.
I would say it feels even better than my Audi S1's steering feel.
But I'm sure all of you who are reading this would agree with me that if there's no solution, it's better to put back the old steering rack.
I will update this topic with the front sway bar poly bushes results, and if there won't be any improvement (like I expect at this point), I will further update the topic with final results after putting back the PR-1N2 steering rack.

Just a quick question, at this point.
My old Pr-1N2 steering rack has about 210.000km on its shoulders. It's old. I don't think it makes sense to install it back. Maybe it's better to buy a new TRW brand one.
There are two steering racks made by TRW:
- JRP 1130 (which has the G250 compatibility)
- JRP 1228 (which doesn't have the G250 sensor compatibility)

ETKA indicates there are two PR-1N2 steering racks:
- 6R1423055D (the one originally factory installed on my Polo), which has the G250 sensor hole;
- 6R1423055K, which doesn't have the G250 sensor hole.
It's easy to associate OEM part numbers with TRW part numbers.
I know my ABS unit only uses G85 sensor for reading the steering angle, so theorically it shouldn't make any difference which one I'd install.
But my concern regards the possibility that the two above mentioned racks might also have a slightly different steering ratio, which potentially could lend me to face the same issue I am having right now.
So, for not having the risk to have again this issue, I'd go for the TRW JRP1130 steering rack, and I'd just put the G250 sensor in its hole, without wiring it to the steering pump's unit.
What do you think?

[ciclo]

Install it exactly the same as before, that is, exactly what ETKA indicates for your 6R, don't let budgets confuse you.

Thanks for all the info/study.

[Jay-Jay]

Luckily the price is almost identical between the two racks.
BTW, as last try, in the next days I'll search for Polo GTIs and Audi A1s with Bosch 8.2i ABS unit and I'll scan them with VCDS. (My mum had a 2011 Audi A1 till 2 years ago... If only I had already scanned it...).
Hopefully there's something different in the ABS Adaptations channels and I can make the same modification on my ABS unit.
Fingers crossed.
If someone casually has an adapmap of a Bosch 8.2i unit installed on a car with PR-1N4 rack, I would be very greatfull if he could post it on here.

In the end, I'll give myself a time limit of 1 or 2 weeks for finding an ABS coding solution. Expired that time, I'll buy a new PR-1N2 steering rack and install it.

[iichel]

I think there should be a solution in the software, it's all just coding and adaptation. It's very likely in the ABS coding.

check your instagram inbox for a coding sheet for esp8.2i, don't share

[Jay-Jay]

Hi to everybody,
just a few quick updates.
I replaced the front swaybar bushings, but it didn't fix the problem.
Then, my focus switched to the ABS coding.
I really have to thank iichel who is giving me a huge support in this.
Our intention has been to make my ABS long-coding the same of a Polo GTI, because it's the only Polo version with Bosch 8.2i ABS unit and 1N4 steering rack.
After having tried many coding combinations (the most of them weren't accepted by my ABS unit), I decided to swap my old ABS unit (HW: AF, SW: AF) with a newer one which has the latest 8.2i firmware version available (HW: AF, SW: BE).


The job was pretty straight forward and less difficult than I expected.
This allowed me to further modify the ABS long-coding, by inserting the value for GTI engine (Byte 15: "41"), which my old ABS unit didn't accept.
So, now my ABS unit is coded for GTI engine, brakes and suspensions. Unfortunately this didn't fix the ESP problem.
To really make the ABS coding 100% like a Polo GTI I should also modify Byte 6 and Byte 14 with Polo GTI values ("02 - 40"), but unexpectedly this unit doesn't accept those values.
Maybe it needs TCU to be installed... maybe BE firmware is not for Polo GTI (AK or BC could be the correct ones?)... or maybe I am missing something else. Who knows...
Cars with Bosch 8.2i ABS unit and 1N4 steering rack exist, so there must be a way to make ESP work correctly.
I could always upgrade to Bosch 9.0i ABS unit, which also supports ESC deactivation, but I want to keep this option for later, only if all the other tries to maintain the 8.2i Unit won't bring me to a definitive fix.

Anyway, does anybody know if these ABS units have parametrization?
I mean: is it possible to write specific parametrizations file with ODIS?
My suspect is that, regardless of the ABS unit firmware version (which plays an important role as well), of the long-coding and of the Adaptations channels, there might be also parameters which differ from car to car depending on what parametrizations file has been flashed from factory.
Do you think it might be possible with ABS units from this era?

_______________________________________
Corious fact: the new 'BE' ABS unit firmware version accepts the coding for 288/232 brake discs even with byte 15 coded for CBZB engine and Byte 4/Byte 12 coded for Manual transmission
_______________________________________
In the while, I am also investigating about possible defects of mechanical components.
I ordered all these new parts:
- inner and outer tie rods, specific for PR-1N4 steering rack;
- ball joints;
- sway bar links;
- front wheel bearings (rear ones have just been replaced together with the GTI rear axle beam).
These same parts currently installed on my car have more than 100.000km, so I want to think I'll replace them for preventive maintenance as well.
Last week I brought my car again to the workshop to check the wheels alignment.

Toe-in has been properly aligned, but I noticed two things:
- camber on front left wheel is -0,75°, while on the right front wheel it is -1,10°. This is a difference of 0,35°. In the past the value was about -1,2° on both sides. Considering the struts and top mounts are new and the height has been adjusted the same on both front wheels, the difference in camber values makes me think the front subframe might not be properly transversally centered to the chassis of the car, despite I installed front subframe rigid collars, which in theory should perfectly center it.
- front wheels caster value is 5,2° and it's the same on both sides. This makes me think the front subframe is properly longitudinally centered to the chassis of the car.

By looking inside the wheel arch, I notice the distance between the rear side of the front subframe and the cassis of the car is a bit larger than it used to be before replacing the steering rack. So, to me it looks like the subframe is positioned further forward than it was before.

Do you think this could cause my ESP problem?

Any suggestion on what else to do/check, is really much appreciated.

[Jay-Jay]

Hi everybody, I have an important update.
In the end I decided to upgrade to Bosch 9.0i ABS unit. Between all the firmwares available, I choose the BG version, which is the same installed on Polo R WRC.



This work required me to modify the position of some wires inside the ABS unit connector.


Then, after many tries, I have been able to insert the ABS coding specific for Polo R WRC brakes/transmission/drivetrain/engine.
I test drove the car on the problematic turns and I can finally say the ESP now works perfectly. It doesn't kick-in abruptly for no reasons anymore and it works even better than when I didn't have this ESP problem before replacing the steering rack.
On spirited driving over roads with a lot of turns, I feel like the car is much more precise and stable. The more I speed up and the more the chassis feels rigid/stiff.
Even the steering weight feels a bit heavier and more direct and precise, even if I didn't change anything in the steering assist coding.
Thanks to the new ABS coding, brakes work much better too, especially the ABS kicks-in later and in a less intrusive/more sporty way.
In the end, I am extremely happy and satisfied.
I can't not thank enough iichel who supported me and tolerated me and the bad luck which always haunts me
So, to really give an end to this topic, I would say that to make a good work, it is also necessary to code the ABS unit also for Audi A1/Polo GTI/WRC drivetrain, which is stored in Byte 6 (and its mirror byte) of the ABS coding.
If tour ABS unit firmware doesn't support that specific coding for those 2 bytes in combination with brakes/transmission/engine bytes consequentially modified, you need to replace your ABS unit with one which has a firmware which support that coding combination, otherwise you risk to have the ESP problem I experienced, which kills all the fun.

P.S. now I can completely disable ESC with the button on the dashboard:
https://youtu.be/bTB0geG5G5s

[ciclo]

Hard, long and creative experience, your tenacity has paid off, thank you very much for sharing it with all of us! You can finally enjoy your improvements.

If you want, please take some time to test it carefully and then return to provide us with a new report, I think it will be greatly appreciated by all of us.
Thank you!!