Why new ABS Unit if no ABS warning light?

[a8 tech]

ABS FIRST.01435 - Brake Pressure Sensor 1 (G201): Electrical Fault in Circuit
Possible Causes
Brake Pedal Switch (F) faulty/jammed
Brake Pressure Sensor 1 (G201) faulty
Possible Solutions
Check/Replace Brake Pedal Switch (F)
See Measuring Blocks
Check/Replace Brake Pressure Sensor 1 (G201)
ABS Hydraulic Unit (N55) may need to replaced
Perform Brake Pump Bleeding
Perform Brake Pressure Sensor 1 (G201) Basic Setting
Replace Brake Electronics Control Module (J104)
Retrieved from "http://wiki.ross-tech.com/index.php/01435"
So if the wiring has no mutual short or high resistance and the brake light switch is ok it leaves only 2 options.Firstly a basic setting of the brake pressure sender and worst case replace the full abs unit .The battery voltage shown will be with the engine off and diagnostic tester connected(hence lowish voltage)they should realy have a battery charger connected when using the diagnostic tester.The radio issue draining the battery is that sorted and can we forget about that bit or is it still happening.So if there is only this fault code stored 01435 at this visit then look for a contribution from vw customer care as you have only just come out of warranty.

[kaygolf]

This isn't sounding too great!!
Near the end of the log it says (sorry this will be a bit long winded but I dont know what's relevant or not . . . )

' - Check the displayed condition of Brake Light Switch -F- when operating brake pedal.
Brake Light Switch -F-: [B]not operated[B]
- Press button after the test

Diagnosis Question

Were the displayed conditions of Brake Light Switch -F- identical with the operation of the brake pedal? Yes

Signal

- Replace ABS Hydraulic Unit -N55- together with Brake Pressure Sensor 1 -G201-
Subassembly, Brake Systems; Repair Group 45
- Bleed brake system (including basic setting).
Subassembly, Brake Systems; Repair Group 47
- Next, performe the basic settting of Brake Pressure Sensor 1 -G201-
Note:
[I]If the malfunction is still present after replacement and basic setting, replace ABS Control Module - J104-

[End of test

Does this mean that replacement of the ABS Unit should only be done after the other things have been tried - they haven't mentioned anything about trying other things first!??

They ran a battery test while I was at the garage today. It says: Cold cranking current (DIN) Load voltage 9.8v Regulator Test 13.8v. I had just driven 30 mins to get to the garage. Is that OK? When they looked in the little window on the top of the battery it just looked empty/black. Does that make sense?

Thanks again - you're a star
Kay

[kaygolf]

Have just thought, you mentioned shorting as a possible issue - when the fuel pump was replaced the diagnosis log shows:
16475 P0091 002
Fuel Metering Valve -N290-
Short circuit to Groud (GND)

Could that be connected or just a coincedance?

Appreciate your thoughts,
Kay

[a8 tech]

the brake switch and brake pressure switch can be checked quite easily in measured value blocks,if the redings arent attained then they need to be checked to eliminate and also to leave only the abs control/hydralic pump to be at fault.

002,1,Brake Test Switch,,Display Range: 0/operated
002,2,Brake Light Switch,,Display Range: 0/operated



005,3,Brake Pressure,,Display Range: -41.0...+292.0 bar\n40.0 bar = Short to Ground\n290.0 bar = Short to Plus


006,1,Supply Voltage,(Terminal 30),Specification: 9.8...17.4 V


125,0,CAN-Databus Communication (Powertrain)

Fuelmetering valve fault can be seen as fuel starvation from engine cutting out and is most likely related to the diagnosed fuel pump,again if this fault is nolonger present ignore.So if only the esp/abs fault is left it is unlikely to effect the running of the vehicle and there may be some other issue to tackle after the abs fault is rectified.Treat the faults one by one.

[a8 tech]

This isn't sounding too great!!
Near the end of the log it says (sorry this will be a bit long winded but I dont know what's relevant or not . . . )

' - Check the displayed condition of Brake Light Switch -F- when operating brake pedal.
Brake Light Switch -F-: [b]not operated[b]
- Press button after the test

Diagnosis Question

Were the displayed conditions of Brake Light Switch -F- identical with the operation of the brake pedal? Yes

Signal

- Replace ABS Hydraulic Unit -N55- together with Brake Pressure Sensor 1 -G201-
Subassembly, Brake Systems; Repair Group 45
- Bleed brake system (including basic setting).
Subassembly, Brake Systems; Repair Group 47
- Next, performe the basic settting of Brake Pressure Sensor 1 -G201-
Note:
[i]If the malfunction is still present after replacement and basic setting, replace ABS Control Module - J104-

[End of test

Does this mean that replacement of the ABS Unit should only be done after the other things have been tried - they haven't mentioned anything about trying other things first!??

They ran a battery test while I was at the garage today. It says: Cold cranking current (DIN) Load voltage 9.8v Regulator Test 13.8v. I had just driven 30 mins to get to the garage. Is that OK? When they looked in the little window on the top of the battery it just looked empty/black. Does that make sense?

Thanks again - you're a star
Kay

Sorry Kay missed this bit and the answer is yes the test plan instructs the technician that the full abs unit requires replacement if all the critrion have been met.The battery looks fine.By the way i think your keeping up fine and better than most of the techs i deal with

[kaygolf]

Thanks - the technical stuff is way above me, but it looks as though I have grounds to ask them why they've jumped straight to the new ABS unit without checking the other things first, which gives me something to work on!

Back to the battery - the charge test like you say was ok, but why is there no colour in the battery window? In my manual it says if the window is colourless the electrolyte level of the battery is too low. Do I need to do anything about this?

Thank you & I'll stop badgering you now, I'm sure you've got better things to do on a Friday night!!
All the best & thanks for all your help, Kay

[a8 tech]

the magic eye should be green for a fully charged battery and clear or yellow indicates low electrolyte levels .To be safe and with hindsight of winter coming replace it for peace of mind.Well done Kay and have a nice weekend,as i am sure vw are in for a battle.

[kaygolf]

Hi a8 tech particularly. Big gap since the last post in this thread, but I wanted to say thanks very much for all your help which enabled me to finally, months later, sort things out with VW. In the end despite a very long and detailed letter (which I wouldn't have been able to write without yours and others help), VW wouldn't budge from their offer of 25% contribution to the ABS unit. I then contacted the SMMT and gave them the same information. The SMMT then contacted VW, and miraculously the offer increased to 80% plus free fitting!!! Needless to say, I accepted this, and the car is now fixed!! I could never get to the bottom of what exactly was wrong, and VW would only say it was as a gesture of goodwill. Anyway, thanks for all your help, and persistance paid in the end!!!

[a8 tech]

Result,well done

[ldn-golf]

hi i have a vw golf mk5 1.6 fsi and have the esp light lit on the dash for about a week and i have got it diagnosed by a friend who gave me a print out G201 01435 brake pressure sensor 1 electrical problem in circuit. The other information he gave me was brake fluid pressure sensor on master cylinder. please can anyone help as i am totally new to vw's.