Check the wiring harness around the injection pump for chafing or broken wires.

Fault 17969 VW engine control unit - Status B
Precondition
The controller detects that there is an excessive control deviation in the quantity adjuster OB3 (N146). The quality adjuster (OB3) is inside of the injection pump.

Status B means that the fault is present intermittently.

Effect on the truck
1. Preheating signal lamp flashes
2. Inadequate handling
3. Engine stalls

Possible causes
1. Connections between quantity adjuster OB3 (N146) and VW engine control unit (N1:99, N1:106, N1:108, N1:116, N1:121) shorted or faulty.
2. Check piston displacement sensor OB3 and quantity adjuster OB3.
3. Injection pump defective.

Search you tube for, VW TDI ALH Injection Pump Quantity Adjuster Bad?

This same thing just happened to my H30D. Was running this morning, hopped off the machine and left it idling. It died a couple minutes later and now it won't start and the glow plug light is flashing. It's never died before so this is strange. I don't have access to the Linde software, any input on what to check?

I have similar problem. 392D. glow plug light is flashing. in pathfinder. 17969 error is shown. what is OB3?? Injection nozzle on third cylinder? or sensor on pump? otherwise motor runs quite good.

You need pathfinder and the correct lead for either the LPG or Diesel engine otherwise you won't be able to access the engine codes if you've just got the standard pathfinder cable.

I'd check the engine speed sensor first though, those things cause all kinds of problems!

You need Linde software to diagnose for faults.
Do you have access to Pathfinder ?