Glow plug control module part # help

[chonchibelly]

Can anyone help me find the part number (or point me to where I can) for the glow plug control module/fuse for a 1998 Jetta tdi A3? This is the part mounted at the top of the firewall in front of the drivers seat. It doesn’t seem to exist in the parts diagrams and a couple of online parts places don’t know what I’m talking about. It has melted and needs to be replaced. Let me know if I can provide any more info. Thanks.

 

[oilhammer]

The AHU's glow control module (relay) is 038-911-253 but I have a feeling that is not what you are talking about.

Most VAG parts have part numbers on them (if you can still read it). Maybe post a picture.

 

[chonchibelly]

The AHU's glow control module (relay) is 038-911-253 but I have a feeling that is not what you are talking about.

Most VAG parts have part numbers on them (if you can still read it). Maybe post a picture.

Ya, sorry. It’s not the relay. So I guess not the ECM. Just the fuse unit that’s mounted on the firewall. I will try to grab a photo shortly.

 

[oilhammer]

Outside the car or inside the car? This IS a TDI, correct, not a turbodiesel? You are in Alaska, and while they did not sell the AAZ turbodiesel in the US, they did sell them in Canada, and some have found their way here, and presumably even more likely there.

 

[MOGolf]

Is it the control module for coolant glow plugs? 191 911 261 B.
Or the 50A strip fuse for it? N 017 125 1

 

[chonchibelly]

Ye

Is it the control module for coolant glow plugs? 191 911 261 B.
Or the 50A strip fuse for it? N 017 125 1

Yes! The coolant plug control module. Thank you. Looks like it’s no longer available...anywhere. Wonder what I’m suppose to do about that? The car would not start (no crank) until I cobbled it together as best I could. It apparently needs to be replaced.

 

[oilhammer]

That will not cause your car to not crank or start. Again, I ask, is this FOR SURE a Jetta TDI with the AHU engine?

 

[chonchibelly]

That will not cause your car to not crank or start. Again, I ask, is this FOR SURE a Jetta TDI with the AHU engine?

Yes. It’s a TDI.

 

[Matt-98AHU]

Ye


Yes! The coolant plug control module. Thank you. Looks like it’s no longer available...anywhere. Wonder what I’m suppose to do about that? The car would not start (no crank) until I cobbled it together as best I could. It apparently needs to be replaced.

As others have said, that fuse is simply for the coolant glow plugs. There are numerous cars running around with that module and fuse melted and no longer operational. It will have zero bearing on your ability to be able to start the car. It's something that is only used to help the car warm up faster in cold climates AFTER the engine has started.

If your car suddenly cranked where it wouldn't before you fiddled with it, I call that a coincidence, not an indication of that being the source of the issue.

Even the actual glow plug circuit (which is on the relay panel inside the car, not the melted bit on the firewall under the hood) has no bearing on if the car can crank or start.

 

[chonchibelly]

As others have said, that fuse is simply for the coolant glow plugs. There are numerous cars running around with that module and fuse melted and no longer operational. It will have zero bearing on your ability to be able to start the car. It's something that is only used to help the car warm up faster in cold climates AFTER the engine has started.

If your car suddenly cranked where it wouldn't before you fiddled with it, I call that a coincidence, not an indication of that being the source of the issue.

Even the actual glow plug circuit (which is on the relay panel inside the car, not the melted bit on the firewall under the hood) has no bearing on if the car can crank or start.

Ok. Thanks for the explanation. Unfortunately, now I have no idea why the car would not crank. Is there any way that there could be anything associated with that wiring that could cause the no crank issue? My glow plug dash light was not illuminating.

 

[Matt-98AHU]

Ok. Thanks for the explanation. Unfortunately, now I have no idea why the car would not crank. Is there any way that there could be anything associated with that wiring that could cause the no crank issue? My glow plug dash light was not illuminating.

Glow plug dash light not illuminating is a symptom of the engine computer itself not being powered on, which sometimes can be from a dud relay 109/J317 power supply relay to the engine computer.

When you first turn the key on, you should get other warning lights on the cluster too, like the oil pressure light and battery light, for example. Are those also coming on when you have the no-crank issue that also doesn't have the glow plug light or check engine coming on? Does the ECU ever store a code for the glow plug light intermittently not working?

It's very plausible you have an intermittent ignition switch issue.

 

[oilhammer]

Ugh, yeah, the A3's ignition switch....

 

[Matt-98AHU]

Ugh, yeah, the A3's ignition switch....

Had a B4 Passat in here awhile ago that had a Meyle key tumbler... the crescent shaped bit that engages the switch had gotten tweaked with use to the point where it would not reliably mechanically turn the switch far enough to actually get to the start position... That was fun figuring out after first replacing the switch and still having the same issue... heh

 

[chonchibelly]

Glow plug dash light not illuminating is a symptom of the engine computer itself not being powered on, which sometimes can be from a dud relay 109/J317 power supply relay to the engine computer.

When you first turn the key on, you should get other warning lights on the cluster too, like the oil pressure light and battery light, for example. Are those also coming on when you have the no-crank issue that also doesn't have the glow plug light or check engine coming on? Does the ECU ever store a code for the glow plug light intermittently not working?

It's very plausible you have an intermittent ignition switch issue.

I did get the other warning lights illuminating. I’m fairly certain that the glow plug light was the only one.

I do get the glow plug light illuminating now that it is starting, but it only comes on for a second or two despite it being 45 degrees out. And it seems to lead to a rough start.

 

[Matt-98AHU]

I did get the other warning lights illuminating. I’m fairly certain that the glow plug light was the only one.

I do get the glow plug light illuminating now that it is starting, but it only comes on for a second or two despite it being 45 degrees out. And it seems to lead to a rough start.

That's normal. Glow plug light should not stay on for longer than its bulb check until you get below about 40 degrees F. And, even though the light goes off quickly, that does NOT mean the glow plugs have turned off. It just indicates that it is good enough to start. You can let it sit for a few more seconds if it helps and the plugs will actually still be on.

If the car fails to crank, it can be the ignition switch still... or even something wrong with the key tumbler that interfaces with the switch.

 

[chonchibelly]

Glow plug dash light not illuminating is a symptom of the engine computer itself not being powered on, which sometimes can be from a dud relay 109/J317 power supply relay to the engine computer.

When you first turn the key on, you should get other warning lights on the cluster too, like the oil pressure light and battery light, for example. Are those also coming on when you have the no-crank issue that also doesn't have the glow plug light or check engine coming on? Does the ECU ever store a code for the glow plug light intermittently not working?

It's very plausible you have an intermittent ignition switch issue.

And I meant to add...yes. The check engine light has been on intermittently since Ive owned the vehicle. It’s been several years since I’ve retrieved the code so I don’t recall the number. But I believe it was a general “check glow plug system” type of code. Plugs are all good, harness has been replaced, etc.

So, otherwise, I’m assuming I should just replace the 109 relay (is J317 the same?) and see if it ever happens again? I believe I have rather recently replaced the ignition switch. Thanks again!

 

[oilhammer]

As Matt said, there are some low quality ignition switches out there. Volkswagen has a newer updated version, they are still available, and while they may cost $60 instead of 6, they are worth every penny since they will actually work reliably.

6N0-905-865