P1780 Code?

[BigJoe13]

2002 1.8T Jetta w/ 09A tip with 100K Miles.

I am throwing a P1780 code and a P0170 (too Lean).

recently I've replaced the spark plugs, coils and the MAF. I think the too lean must be an 02 sensor or a vac leak.

What is the p1780 about? Anyone?

Thanks,
Joe

[BigJoe13]

Also, the ASR light comes on and then the car shifts really hard or rough. and only up to 4th gear.

When I turn off the car and restart it the ASR light goes off and the shifting returns to normal. but I still have the all to common hard shift from 2nd to 3rd.

[HugoT]

i'm bumping this.

I'm also getting the same exact symptoms with the P1780 code.
Engine intervention readable - no communication between ECM and TCM.

I also have P0171 - System too lean - bank 1

For that I have replaced spark plugs, air filter, fuel filter, and cleaned the MAF. It looks, based on searches, I have to either replace the MAF (since I unplugged it and nothing different happened with the car's idle).

I'm posting that because I'm not sure if it has anything to do with the P1780 code.

Today while driving to work and in traffic, the ASR light came on and the thing shifted like crazy. I went into tiptronic to keep it on one gear and pulled over as soon as I could. Shut the car off, turned it on and the car ran fine for the next 35 miles to work.

Any ideas?!?

[joepreston]

I am having the same problem as well, '02 GTI 1.8T Tiptronic. Same thing happened to me in traffic today with the same result. My check engine light was on for a while, now it's off again.

Anyone have any solutions?

[ECPunk]

wow... i hope someone has an idea what is going onhere because i'm experiencing the same thing. Hopefully we can get some answers.

A few months ago I had the transmission serviced, plus new plugs, coils and some other things done.

Recently the tranny has been acting up. I'll hit a hard bump and the ASR light will come one the the jetta will be jerky and shift like crap. I will, like everyone else, have to pull over, turn off the car and then restart and things are fine for a while.

I too have been using the triptronic lately to try and aviod having the tranny shift to much. just now on the way home from work, when i got in the city the ASR light came on again soon as i shifted back to auto and the check engine light came on. I don't have my computer on me, but i will check the code tomorrow.

I hope this thing isn't shot. I was reading about replacing certain soleniods may fix these issues. Is that correct? I'll post soon as i know what the code is.

I hope we all can fix these issues cheap and easy.

[ECPunk]

Ok, just got my code read: P1780
engine intervention readable - no communication between ECM and TCM, explaination: open/short circuit condition probable cause, poor electrical connection, failed TCM.

Those are the options listed. Hopefully someone has some input

[we be dubbin]

Same thing has happened to me 3 times now and its getting annoying. Same code P1780 does anyone have any ideas.

[dooboosal]

SAME THING happened here!
ASR and ENgine light came up and the car
shift and jerks crazy.
I connected to my mechanic's computer and
P1780 has to with transmission
I dont know what exactly tho
Gonna try changing transmission fluid

[dooboosal]

P1780- Manufacturer Transmission
Valve Transmission

[CoolAirVw]

OBDII codes are too vague.

Here's the definition I got when I looked it up.

Torque Reduction Malfunction.

All ya'll's next step should be to scan with vag-com. Maybe it would give you another code that would be more specific and might point you right to the problem.

Modified by CoolAirVw at 11:24 AM 3-29-2010

[we be dubbin]

Thanks for the info CoolAirVw. I am taking it in for a VagCom as soon as my ABS sensor comes in and I can drive it again

[Dutes]

My fathers 02 GTI 1.8T same exact symptoms and codes!!! Did anyone find out any other information on this major issue? I'm trying everything to fix this for him.

[CoolAirVw]

The more times I read through this, ya'll need to fix your engine performance problem first. This isn't a trans issue.

[john.jetta02]

I was wondering if you've taken the car to be scanned with vag-com. I'm having the same symptoms. Anything would be helpful at this point.

[gccch]

We are having this exact same problem. Have there been any solutions identified?

[gccch]

Please help. We have the same issue as the original poster and have been through two cycles with a local shop. Latest vag codes are 16486, 18032, 01166, P0102, P1624

This prompted them to check vacuum with smoke test and found a broken oil dipstick (replaced) and a vacuum line (replaced). On driving home we had the same issue occur with some rough shifting and ASR flash. Very frustrating.

Any ideas?

[glxcited]

Getting same codes 1780, 1624 along with ECP, ASR,CEL and terrible shifts. Subscribed.

[CoolAirVw]

Latest vag codes are 16486, 18032, 01166, P0102, P1624

Might want to provide definitions for those codes. Some of the folks here (Me) might be able to help but dont have time to look up the code definitions.

P0102 is MAF (from memory). usually this will require a new MAF sensor, but it could be wiring issues ect. MAF sensor is a key "player" in fuel injection and in the load signal that comes from the engine computer to the trans computer.

[bayotte]

A bad MAF will cause a p1780 and extremely rough shifts.

[CoolAirVw]

A bad MAF will cause a p1780 and extremely rough shifts.

I think he's saying what I did a bad job of saying in the last post...

Fix the obvious stuff first. Fix the maf code... then the load signal will be correct and maybe the other code will go away.