Questions about codes for glow plugs, turbo, and EGR

I'm new here but I need help with my 2004 Jetta TDi. I have been driving 100+ miles every day for the last 9 months with no issues. The other day I drove 350 miles, came home, let is sit overnight, and then when I started it the next day, it cranked longer than normal. Now my MIL is on, the glow plug light flashes when I turn the ignition on, and the traction control light is on. Here is a list of the codes and what I understand them to mean:

17058 cylinder 4 glow plug circuit Q13
19794 control circuit for glow plugs
19829 intake manifold change over valve fault
16629 wastegate solenoid A low input/short to ground
17903 egr cooler switch over valve open or short to ground
19557 intake manifold flap open or short to ground
19558 intake manifold flap no signal
16705 ign engine speed circuit range

This is also an ABS code 01314 which I guess means no communication with the ECM

Is there a harness or plug I should check? I haven't been able to find any wiring diagrams or I probably would have figured it out. It seems like the sensors and glow plug circuit must share a power supply or ground but maybe not. I got as far as checking the glow plugs and they all read 0.5 ohms. Any help is greatly appreciated. Thanks.

I would start by checking all of the ground connections, particularly those under the battery.

I think you mean the major chassis ground hidden under the airbox. That ground worked loose twice on my car causing problems. The second time I replaced the nut with a brand new locknut.

Also check the battery condition and voltage while running.

I checked the grounds under the battery. Didn't find anything wrong.

Vermontdi said:

I checked the grounds under the battery. Didn't find anything wrong.

Click to expand...

Do you have a multi-meter so you can check the battery voltage, both with car off, and engine running? If you clear all of the codes, do they all come back right away?

That seems like way too many faults at once to be a wire/harness problem...

More like bad ground(s) and/or low voltage....or water got into something.

Static voltage is 12.5 volts and running is 14.7 volts. It cranks fine so I doubt it's a ground. They're all together

Vermontdi said:

Static voltage is 12.5 volts and running is 14.7 volts. It cranks fine so I doubt it's a ground. They're all together

Click to expand...

14.7v is as good as it gets.

Have you cleared all of the codes? Do they all come back right away?

I tried clearing the codes but they come right back. There must be an open wire somewhere or something like that. Maybe a short to power but I highly doubt it. All those sensors are connected to the diesel direct fuel injection engine control module in the plenum. Maybe a power or ground to that module?

Vermontdi said:

Maybe a power or ground to that module?

Click to expand...

Yes, or connection at the ECU...I dunno. This is a weird one.

That's a lot of codes for a car that was running fine. Try following the wires for those devices, you may find some damage. Try researching those codes to see if there any common component issues listed.

So as was first suggested you checked the major grounds under the air box/battery tray. Did you take those connections apart and clean them till they were shiny? Not only shiny connectors but also the bolts and car body they connect to? That would be my first step if I cleared the codes and they came right back. Don't forget the black wire from the battery to the bell housing.

If that doesn't work, then start following and testing wires.

So I found a wiring diagram that showed me that all those sensors/actuators are powered by relay 109 through a fuse. So after a bit more research I found that power is supplied through fuse 34. I pulled it out and it was blown. I replaced it, cleared the codes and it's all good now. Except that half the engine compartment is torn apart. But that's ok. I found where a chipmunk has been living in there and destroyed the cabin air filter and I'd never have found that otherwise. Thank you all for your help.

Glad to hear you got it sorted.