0AM DSG Fault codes P173A P173B P173C P173D P173E P173F



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Apr 30, 2014
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Just want to share some information i found as trolling the web gave very little information on this subject.

0AM 7 speed mechatronics failed on a Skoda Roomster (this box is obviously the same for multiple cars VW, AUDI, SEAT and SKODA, the original fault was to do with the hydraulics inside the unit, this was easily repaired by ECU Testing in the UK for a good price so when refitting the unit we had a fault come up....

005948 - Position Sensor 3 for Gear Selector
P173C - 000 - Implausible Signal - MIL ON
Freeze Frame:
Fault Status: 11100000
Fault Priority: 0
Fault Frequency: 11
Reset counter: 40
Mileage: 235182 km
Time Indication: 0

so after a lot of investigation I've learn't some good facts about the gearbox and mechatronics unit. Basically when your looking at the hole left in the gearbox when the mech box is off you can see some little plastic clips clipped to the selector mechanisms, these little plastic holders house magnets, one either side of the little plastic holder that tell the mech box which gear the car is in. see pics below, 1st pic is for clarity

magnets circled in red (has the letters N and S stamped into them North South perhaps??

one of these clips had come off and a tiny 5mm squared magnet had fallen out (thought it was a gear tooth), we were so so lucky to find the parts (the magnet had come out from the holder) and very carefully clipped it back on.

now another thing to mention is when it says position sensor 3 this does not mean gear selector 3 if you look at the above picture it shows you the gear leavers now position sensor 3 that we had a problem with was actually gears 7 and 5 sadly i do not know how its set out but you have gear selectors for 1&3,2&4,5&7,6&R so sensor 1 maybe for R and 6?, sensor 3 100% for gear 7 and 5 etc etc....

you can see the black plastic things sticking up will be reed switches or some other type of magnetic switch that when the gear selector moves it makes the corresponding switch telling it which gear its in, if it can't see this then it throws up one of the faults.

so as i couldn't find hardly any info on P173A P173B P173C P173D P173E P173F i'm hoping this will help people in the future.

so it could be the selector fork not engaged in the piston in the mechatronics box when reassembling, the magnet clips fallen off, a broken reed switch

2 other things to mention this helped massively its a VW PDF on the 0AM gearbox

http://mrtn.m4ti.net/mk5/Jetta & Go...nsmission/7-speed dual clutch gearbox 0AM.pdf

also thanks to ECU Testing in the UK who repaired the original fault with the internal Hydraulics.

always remember to do basic settings from the Ross Tech write up before driving on it.
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Gone But Not Forgotten
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Jan 29, 2014
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To add to this thread those magnets should be referenced with a Gauss meter or an old style inductive ammeter to determine position if in some cases unmarked!