View Full Version : p1750 power supply low voltage

08-05-2010, 10:04 PM
Can anyone help with what might be causing this transmission fault code?...It is the only one i get and makes it unable to see what gear i'm in when using the tiptronic mode. I can clear the code while i'm driving and it will be ok until i turn the car off then again it comes back up. Car is a 2002 Passat GLX 4 motion, clearly not an B5 A4 But the auto trans is the same

08-05-2010, 10:20 PM
So I have the symptoms right:

- Clear codes and everything works perfect.
- Once car is shut off and started again, this code sets
- Whilst this code is set, everything still works perfectly, including tiptronic mode
- Other than the code (do you get a Check Engine Light with it?) the only other problem is the inability to see the selected gear when using Tip mode
- Tip mode still works fine and the gear number display (12345) is still shown, but there is simply no highlighted selection when using the tiptronic as the gears are shifted up and down (+/-).

Is that all correct?
I suppose the first thing I would do is check the TCU for water ingress problems. While you're there you may want to check the voltage supply at the TCU, perhaps even during cranking, to make sure it isn't going too low. If that looks good, I'd check the 2 connectors at the transmission - 1 for the Multifunction switch and 1 for the internal solenoids/sensors. Make sure there is no corrosion on the terminals. Any codes in the ECU?

08-06-2010, 03:52 PM
Yea those are the symptoms exaclty, I have to check the plugs at the trans first, I really it not the tranny computer

08-06-2010, 09:41 PM
Could also be bad battery connection, or have you recently pulled the battery or had it die.