01m wont shift into 4th

thompsoncustom

Well-known member
Joined
Nov 15, 2017
Location
iowa
TDI
bora
The other day coming home from work my tdi wouldnt shift into 4th gear and through a code. I cleared the code(improper gear ratio) and topped off the tranny guild but no luck.


No it's not showing any codes but will not shift into 4th gear and the shift points are all really high, shift after 3k rpm.

I'm thinking maybe a bad speed sensor what do you guys think?
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
Another 01M is biting the dust.

Common failures of the 01M is the spool valves in the valve body wear out, allowing fluid pressure to return to the pan instead of the clutch packs/torque converter.

You May be able to fix it by replacing the valve body, but that's assuming the clutch packs haven't been torched yet. Otherwise you're looking at an overhaul or 5 speed swap in your near future.
 

Rob Mayercik

Veteran Member
Joined
Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
Hang on there, Nero - that sounds almost exactly like what I experienced a year ago when my G68 sensor bit the dust.

Mine seemed fine, right up until it decided to fail while I was doing 70mph on the highway and dropped me out of O/D. When I pulled over and "rebooted" the car (read: key off, then restart), then I was getting only 1-3 and shifts only occurred harshly in the 3200-3500rpm range. I just took it real easy on it to get it home, reasoning that shifts that jarring weren't healthy in the long-term for the trans, so tried to minimize them. Fresh sensor and it's been shifting flawlessly ever since. Even seems to have gotten rid of the occasional "intermittent TCC lockup failure" code I was getting from time to time, which makes me think a sensor on the borderline between good and bad could have been confusing the TCU.

The only downside to doing the sensor is you have to pull the transmission mount apart to get at it (and be careful, it's aluminum and it's easy to strip the threads out), but it might be worth giving it a replacement G68 output speed sensor first. If that does the trick, it's $50 or so + time well spent.

O/P, How many miles on your car?
 
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thompsoncustom

Well-known member
Joined
Nov 15, 2017
Location
iowa
TDI
bora
340k on it. Just took it for a test drive and it was shifting into 4th for awhile but on the way home it dropped down to the hard shift points again so I parked it.
 

Nero Morg

Top Post Dawg
Joined
Oct 19, 2017
Location
OR
TDI
2014 A6 TDI, 2001 Jetta TDI, 2014 Passat TDI
That's a lot of miles for a 01M. You could try the cheaper option first, but I wouldn't hold my breath just yet. Fluid is thicker cold, so it makes sense why it acts up when warm.
 

thompsoncustom

Well-known member
Joined
Nov 15, 2017
Location
iowa
TDI
bora
If I could find a good donor car around here I'd just do the 5 speed swap just haven't found one yet.
 

Rob Mayercik

Veteran Member
Joined
Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
I was about 360K miles when my sensor failed. The sensor was original to the car, but not the trans.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
If you're up for the swap and the car is in good nick, go for it! You'll find a TDI 5-spd somewhere.
car-part.com will have everything, shipping by common carrier is reasonable.
If it was me, I'd find someone who has done a few, drive there and pay the extra expense.
 
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Rob Mayercik

Veteran Member
Joined
Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
I still think the sensor's worth a shot - if it does help, it buys him time to get the swap logistics in order.
 

thompsoncustom

Well-known member
Joined
Nov 15, 2017
Location
iowa
TDI
bora
Pulled the codes again this time got the gear ratio one and output shaft speed sensor no signal p0722 I think.

I'll get the speed sensor ordered and will see what happens.
 

flee

Veteran Member
Joined
Sep 19, 2011
Location
Chatsworth, CA
TDI
2002 Jetta GLS wagon
Pulled the codes again this time got the gear ratio one and output shaft speed sensor no signal p0722 I think.
I'll get the speed sensor ordered and will see what happens.
When you remove the sensor you can check the diff fluid level and condition.
It's pretty easy to suck it out and replace it with some nice, new synthetic fluid, too.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
No, you can't. That is NOT the sensor he is talking about.

The TCM uses two sensors for its own speed monitoring, input and output, which are both located on top of the case. The output (the one in question) is UNDER the mount bracket.

The vehicle speed sensor in the diff portion of the case is not used by, nor cared about by, the TCM. That is just for the instrument cluster, radio (for speed volume regulation), and the engine controller for cruise control.

Chances are the transmission has an internal problem, and the sensor DTC is just a symptom. However, sometimes the little harness for the output speed sensor as it goes across the top of the transmission gets a spot rubbed through and causes some issues. You'll find out once you get the mount bracket out, and the sensor out.

Please look at this helpful thread:

http://forums.tdiclub.com/showthread.php?t=248847

Notice the picture of the exposed top of the transmission.... G68 is the output speed sensor for the TCM.
 
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C Squared

Member
Joined
Nov 10, 2012
Location
Fond du Lac
TDI
2 02 TDI's
Drove a 2000 tdi home last fall after fixing some issues.
It didn't shift to 4th. Parked it for the winter. Tornado issues....
Cleared misc codes and took it up the road. Shifted to 4th and 2Krpm at 60.
I'm a 5 spd guy. Got this one cheap and with issues. Bad Vac pump. Bad starter. Timing out of spec. Looks to have a new turbo.
Think it will keep shifting? runs fine now.
 

Rob Mayercik

Veteran Member
Joined
Dec 19, 2001
Location
NJ, U.S.A.
TDI
2002 Jetta GLS, Baltic Green/Beige
Probably wouldn't hurt to do a fluid/filter service on the thing, C-Squared (including the diff oil, which is separate from the ATF). If the fluid coming out looks reasonably good, you can probably run it for a while and be OK.
 

C Squared

Member
Joined
Nov 10, 2012
Location
Fond du Lac
TDI
2 02 TDI's
Probably wouldn't hurt to do a fluid/filter service on the thing, C-Squared (including the diff oil, which is separate from the ATF). If the fluid coming out looks reasonably good, you can probably run it for a while and be OK.
My thoughts, but I don't have personal experience with the autos.
And, I plan to sell it and i like to stand behind my stuff as much as possible.
 
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