Jetta intermittent starting problem

jetta
volkswagen

#1

Hi all, I have a 2007 Jetta with 75k miles on it. What I’m running into is that out-of-the blue, the car will not start. Generally, it turns over, but never starts. One time, it started but shut itself off after 3 seconds. Warning lights that flash are the steering wheel indicator and sometimes the traction control and immobilizer lights. I replaced the battery hoping that that would fix it, but it hasn’t. Notably, the engine light is usually on when starting and goes off after 3 seconds, but now it doesn’t go on at all.

The issue first started a few weeks ago, but I could successfully start it 15 min later. No issues for 2 weeks, until the traction control light came on and stayed on while driving. Nothing for a few days, and then suddenly could not start again (tried over a period of 3 days). Towed to a shop, where it started after two days. Any advice?? Thanks!!


#2

Try some heet or seafome etc, could be a gas line freeze, I assume no check engine light, and I thought heet was a thing of the past until my car would not start 2 weeks ago at 14 degrees and had not had a problem in sub zero the week previous, a dose of heet and some starter fluid, after an hour it finally started and no problems since. heet has to be in my winter maintenance from now on. Making the assumption your temps were sub freezing and no cel.


#3

This sort of sounds like a problem with the theft deterrence system to me. When you turn the key to “on”, but before cranking, the check engine light should be on. If it isn’t, that’s where to start. You car may think you are a thief and trying to steal it, so it is laying down the law, pretending not to even recognize there’s a key in the ignition.

Just curious what the shop said. After all, it’s a little unusual isn’t it for a car not to start for two days, then start on the third. Why did you accept it back from them, since with no explanation it wasn’t fixed?

You may need to go to a dealer of VW specialist for this.


#4

Based on the OP’s description, I agree with GeorgeSanJose that this is likely to be a problem with the Theft Deterrent System. And, I also agree that the dealer may be the only one who can deal with this situation effectively.


#5

@Barkydog - it was sub-freezing the first time it happened, but definitely not the second time.

@GeorgeSanJose - I haven’t accepted it back from the mechanic yet (a local VW specialist / tuning shop), since fortunately I can bike to work. I think I’ll pick it up from there on Monday if all seems to be fine, and consider taking it to the local dealer. It’s going to be hard to explain the problem to them if it is starting like normal though.

They did notice that in my fuse panel, one of the fuses they had expected to be 5A on all mk5’s had a 10A fuse in it, for what that’s worth. When it wasn’t starting, they had the computer hooked up and sometimes saw low voltage error codes, but sometimes there were no error codes at all.

I know the battery is fresh, so I guess that leaves the alternator, ECU, and wiring? How could the immobilizer come into play (I know the light was on at some point, so I can’t throw it out, but what would it do?)?