Check Engine Light stays on in cold weather

[The Dispather]

Hello all.

I have a 2004 VW Jetta TDI.

Whenever the weather gets cold out, say 40's or lower, after three or four starts, the check engine lights comes on ad it stays on. Once the weather warms up, after a few starts, it goes off.

I am waiting for the yellow squgigle on the dashboard to go off before I actually crank the engine. I even wait a few more seconds than nescessary to make sure I am waiting long enough.

Can anyone help me out with this problem?

Thank you all.

[Joe_Meehan]

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.
Regarding warning lights:
1) if the coolant temp light comes on, shut off the engine ASAP
2) if the oil warning light comes on, shut off the engine ASAP
3) if a FLASHING MIL/CEL comes on, shut off the engine ASAP
ASAP means driving to the berm of the highway right now and not waiting for the next exit.
But if the MIL/CEL is not flashing, then it's not an urgent indicator.

[Schwrtz27]

go get your code read, we will look it up, and tell you how to fix it.

I've got 10 bucks its a glow plug code!

[Formula1TDi]

I second that, the stealership told me I have a glow plug issue. My light is on right now, but when it gets warm it will go off. The Glow Plug rail is $66

[The Dispather]

Thanks for the advice all. I will try and get those codes read.

I was suspecting that it could be a glow plug problem. I will post back both the english translation and the code number once I get it done. Give me a few days please.

[TDI-Tom]

Hello,

Try this TDI FAQ: http://tdiclub.com/TDIFAQ/TDiFAQ-8.html#8)
Scroll down to item d. "MIL"
This FAQ was very helpful to me and I resolved the "check engine light" syndrome by recognizing one glow plug had failed. The code readout said it was glowplug/heater cylinder No 3, then later changed its mind and said it was glowplug/heater cylinder No 1. Turns out it was cylinder No. 4 glowplug that read 350 Ohms whereas the other three read 0.8 Ohms. I replaced them all at once (recommended.....read the FAQ). This one was tough because here in Arizona, the outside airtemp is usually so high, NO glowplug would be acceptable.... You know its warm when you get into the vehicle at the end of the day and the coolant temp gauge is aleady up 1.5 notches on the scale even though its been sitting for 8 hours
Anyway, I reset the fault code a couple of times and it did not come back until the coolant temp was in the 69° F range (reported in the freeze frame data associated with the fault code) in late October. That was when I read the rest of the TDI-how-it-works in the Bently book, and learned the glowplugs *always* come on for thirty seconds everytime you crank the engine (called afterglow), regardless of coolant temperature. It was just cool enough to make that one cylinder with the failed glow plug run rough enough to trip the fault detector (but it guessed wrong as to which cylinder was at fault).
Good Luck!
P.S. In this vehicle, here in Arizona, the preglow has never come on since I've owned the car. Thats why I did not understand I had a glow plug problem until I read the fault code and read about the afterglow.

[ColoradoRich]

There are some other threads in this Forum that recommend to go to Autozone (or another parts store) where they will provide you a code reading free of charge. I did that and received code number P0380 (malfuction in electrical circuit for glow plug/heater circit "A").

But, the best news is that Autozone managed to simply turn it off. It's not been back since (2 days and counting). I think mine came on after I didn't crank the ignition long enough to make sure it was fully started. No big deal but it may have cause a little glow-plug malfuction CEL alert.

I'm hoping it will not return.

[The Dispather]

Well, alias, I finally got to Auto Zone and got a computer readout of my problem.

Code: P2108

Definition:
Throttle Actuator Control Processor Performance

Explanation:
Open or short circuit condition

Probable Causes:
1. Poor electrical connection
2. Failed Trottle Actuator Control Module

[weedeater]

accelerator pedal. If it works, don't worry about it.

2nd point: this might not be the actual text associated with this code since the car is a diesel and the codes can mean different things. Check ross-tech.com and see if they have it on their lists.