What are these wires?

[matuva]

Yesterday, as I was working on replacing the downpipe and fitting a BD one, I noticed that 3 wires from the harness to ECM are cut

Those are a white, light grey and yellow ones.



Anybody has an idea of what they are for?

 

[Paveltolz]

Generic Haynes Manual doesn't show a diesel engine control schematic. What it does show is:
White wire at PCM = Trans Shift 3/2 Solenoid for 4L60E only or (second white wire reference) Ignition Control (IC) which must be for gassers as it shows that one running to a distributor.
Not seeing a light grey, just the "Grey" which is either a 5v reference or EGR solenoid.

Yellow could be either the coolant sensor. The Haynes Diesel manual does have a schematic for the glow system and shows a yellow wire running from pin B on the GLow Plug Relay to PCM for Glow Plug Relay Control.

My good manuals are all OBD II so I hope I haven't wasted your time.