96 Passat wont start all of a sudden

My 96 Passat TDI was working great. The only issue was the battery. I would drop it off at autozone get it charged up and it would be fine but slowly over the course of a month or so it would get to the point where if you weren't careful starting it it wouldn't be able to power the starter more than a few seconds.

My parents just took it on a road trip to Canada from Florida. It was working fine they came back and parked it at my house (I'm in TN currently). The next day it would not start and the battery was dead. It was parked on a hill so we pushed it down (pop the clutch to start it). It didn't work so we hooked it up to the jumper cables off a different car and it will crank and crank but not start.

The check engine light and glow plug light are NOT turning on. I got a different battery for it and I bought a new relay 109 and popped it in. It will not start. It starts if you spray a little bit of starting fluid but wont stay running. The stop fuel solenoid on the car does click on when you turn the key but just to be sure I did run a wire to it from the positive terminal of the battery and that did not help. It still clicked when we gave it power from the positive but the car didn't start.

Anything else I should check? Could trying to jump it have fried the ECU?

First, don't use ether.

Second, can you communicate with the ECU via a scan tool?

Could be your ignition switch is bad (very common).

Low voltage, repeatedly, is not good for any electronic components. The battery should have been replaced right away if it was suspect. You can also ruin alternators running with a bad battery, too.

Someone stole my OBD-II scanner but I can borrow one or do you mean a specific volkswagen scan tool? I won't be using ether to start it we just used it in the beginning just to see if it was a fuel delivery issue. Used a small amount. It's got a good battery in it now I pulled it from my other car to rule out the battery issue but yeah I should have replaced it long ago.

Well I always prefer a real VAG level scan tool, but at this point anything is better than nothing.

It really does sound like your ignition switch may be bad. Usually some other stuff, like the blower, won't work properly either though.

Either way, if the preglow lamp and the MIL do NOT come on when you turn the key on (and all the rest of the cluster lamps work), then your ECU is not being powered up OR it is just dead.

I'd check all the fuses, too.

I checked all the fuses and they were good. I will check the blower and get an OBD scanner. Is there a way to check the ignition switch?

I agree the ignition switch is problematic on these cars and it's best to replace them with an OEM from the dealer. DO NOT buy a replacement one for $10 even if it's from one of the reputable vendors, they simply do not last.

But, backfeeding the power to the stop solenoid via a direct connection should have bypassed the ignition switch issue. Usually when the switch gets to the point of being intermittent you can't even crank the starter.

This is where a Vag-Com is invaluable, if you're planning on keeping the car you should definitely pick one up.

You can unplug the switch while it's in the car and plug a new one in and see if it starts. If it does, then you will have to replace the switch. If not, then you know to look elsewhere.

The starter will crank all day long but no start with power supplied to stop solenoid.

I actually have that VAGCOM cable back home in florida and vagcom software downloaded. I think it works on windows XP so I could probably have them ship me the cable and I could install XP on my laptop. In the meanwhile I will try to borrow an OBDII reader to see if any response from ECU.

What do you mean about plugging in the switch? From what I saw online it seems like a pretty involved process getting the switch out due to it's placement. I will probably go with the method that leaves the collar intact.

You can just unplug the wiring from the switch and plug it into the new one, then turn it with a screwdriver.

Plugged in new ignition switch and same result. I still have not been able to get my hands on a scanner, hopefully today.

Borrowed an OBDII Code scanner and got these codes! So I guess ECU has some power?

P1619 P1617 P1144

Anything else you guys can think of for me to check? I'd just take it to a mechanic but I don't think there are any around here. Closest "big" town is 10k people on the Kentucky Tennessee border and I don't think they'll know how to work on an old TDI lol

Which part of Tennessee? Check the VCDS locator. There's probably someone nearby with vag-com. Also, if you're so inclined to take it to a mechanic check the trusted mechanics list. Either Knoxville or Nashville shouldn't be too far. Use someone's AAA and get a free tow.

Those codes are glow plug and maf related. But it's tough to say that's the real problem without vag-com. I have a spare BK ecu here in Asheville and could mail it over to you if you'd like. That could assess the ecu possibility.

I am not in a super big rush to fix it. As long as I can get it fixed by mid october I should be golden. The MAF code can be ignored because I unplugged the maf when trying to start it that's what probably triggered it. Knoxville isn't super far, about an hour and half. I used the VCDS locator and found someone in knoxville that has one. I PMed you about the ECU.

I pulled codes and these are the codes I got. I tried to start the car after clearing the codes and none of the codes came back.

So why aren't you getting fuel? Clogged fuel filter? Broken fuel line or leaking IP seal letting the injection pump lose prime? Crack the nuts at the injectors and crank-- if you get fuel there it's because it's losing prime somehow.

I doubt it's your ECU at this point. Unless you lost compression in that one day, you have a fueling issue.

But the glow plug light and check engine light are not coming on that's why I was thinking ECU problem. I'll crack the nuts and check.

Oh, didn't realize they still weren't coming on. That's certainly wrong, and if you've tried a new ignition switch and relay 109 a new ecu would rule out problems. Without a check engine light at key on you won't get fuel.

Do you know what ECUs will work with my vehicle? Do I have to get the exact same one? Or can I get one from a different car?

I tried a new ECU and still no dice. Do you guys have any other ideas? Pleasee help. Should I get a new glow plug relay? Will that make the check engine light not come on? Are there any grounds I should check?

I had an electrical short on the left tail light do you think that is contributing to it? Everytime I popped in a fuse it would short out right away.

On my MK3 Jetta when I have this condition it has been relay 109 every time.
No glow, but cranks no problem.

Should I get another relay 109? This one has a brand new one. I did get it from autozone but it looks like an OEM one has the VW part number on it

Is your glow plug light coming on for a split second when you turn the key? If so, then your 109 relay is not the problem.

No glow plug or check engine light comes on. The temp light, battery and oil lights come on. The temp light goes away after a few seconds. The oil light flashes when cranking.
This is the new relay 109 I got.

I had that problem and it was the 109 relay. Mine was labeled upside down...so when I replaced the relay the numbers were upside down compared to the rest of the relays. look at the blades from the old relay to ensure you put it in the same. sorry if you caught that already, but you might not have seen it. hope you get back on the road soon.
Bill

air

do you have air in you fuel lines?

i ran into a similar problem with my 97 passat it only takes a pin hole one
the suction side to cause problems. check it out.

Since you said you've already replaced the ECU to no avail I was going to suggest opening it up and verifying that both chips are seated completely in their respective sockets but that's likely moot now since the replacement is showing the same symptoms. Look upstream from the ECU but down stream from the 109 relay is what I'd do once making sure the chips were seated even in the new-to-you ECU.

Are you absolutely positive that you've tested the fuel solenoid in a way that definitively rules it out? If hearing for the 'click' while backfeeding it from the battery and it's faint, I'd pull it out and test it to see it move and just to look for build up in the IP.

That left taillight that burns out quick, although seemingly unrelated what do you know of the history on that part of the car?

I don't know any history on the car I bought it used without any records. I got a new relay 109 straight from VW and it didn't fix the issue. I can check the fuel solenoid again and make a video and post it. I will also make a video of all the dash lights so you guys can see.

I'm still trying to get this car running. Put in a new battery but the vagcom thing I had stopped working. These were the old codes.
I have tried two different relay 109s. IS this thing supposed to click when you turn the key? It feels like nothing is happening to it, like it's not getting power.

Also I noticed a ground in the rain tray with no wire hooked up to it. Since I swapped ECUs so long ago I don't know what attaches there. Could the ground cable have come off somehow?

Here is video of the dash and me cranking the car

Have you tried jumping the relay 109? You would need to jump pins 30 and 87. If it starts, then the relay isn't being told to come on. These are ground-side switched by the ECU.