Dash is out, car is running
5 wires going to the engine on the right hand side behind the relay block were responsible for the non-starting issue.
Various other little repairs done but now the car runs and I have reconnected the OBDII socket, I can scan for codes:
Engine:
P1635 - Data Bus Powertrain, Missing Message from A/C Controller
Engine:
P0571 - Brake Switch A, Implausible Signal
Engine:
P161A
Engine:
P161B
Engine:
P161C
Engine:
P161D
ABS:
00668 - Supply Voltage Terminal 30
ABS:
00778 - Steering Angle Sensor (G85)
ABS:
00287 - Right Rear Wheel Speed Sensor (G44)
Airbags:
01638 - Crash-Sensor for Side Airbag; Rear Drivers Side (G256)
Airbags:
01222 - Crash Sensor Side Airbag; Passenger Side (G180)
Airbags:
01228 - Airbag Cut-Off Switch for Passenger Side (E224)
Airbags:
02756 - Redundant signal path of Airbag cut-off switch - front passengerside (E224)
Airbags:
01217 - Side Airbag Igniter: Front Driver Side (N199)
Airbags:
00532 - Supply Voltage B+
Airbags:
01578 - Airbag Deactivation Warning Lamp, Passengersside (K145)
Airbags:
00588 - Airbag Igniter - Driver Side (N95)
Airbags:
00589 - Airbag Ignition Circuit 1 - Passenger Side (N131)
Power steering:
00778 - Steering Angle Sensor (G85)
Power steering:
00778 - Steering Angle Sensor (G85)
Central electronics:
01493 - Bulb for Blinkers, Front Left (M5)
Central electronics:
01505 - Bulb for Blinkers, Rear Right (M8)
Central electronics:
00988 - Lamp for Stop Light, right (M10)
Central electronics:
01504 - Bulb for License-Plate Light (X)
Central electronics:
00984 - Left Tail Light (M4)
Central electronics:
00985 - Right Tail Light (M2)
Central electronics:
01333 - Door Control Module: Rear Left (J388)
Central electronics:
01334 - Door Control Module: Rear Right (J398)
Central electronics:
01320 - Control Module for Climatronic (J255)
Central electronics:
01332 - Door Control Module: Passenger Side (J387)
Body/convenience system:
00896 - Trunk Lock Unit (F256)
Body/convenience system:
00332 - Control for tank flap
Body/convenience system:
01331 - Door Control Module: Driver Side (J386)
Body/convenience system:
01334 - Door Control Module: Rear Right (J398)
Body/convenience system:
01332 - Door Control Module: Passenger Side (J387)
Body/convenience system:
01333 - Door Control Module: Rear Left (J388)
Body/convenience system:
00532 - Supply Voltage B+
Body/convenience system:
01320 - Control Module for Climatronic (J255)
Driver's door:
01811 - Supply Voltage for Door Controller, Drivers Side (J386)
Driver's door:
01330 - Central Control Module for Central Convenience (J393)
Rear right door:
01814 - Supply Voltage for Door Controller, Rear Right (J388)
Steering wheel:
00446 - Function Limitation due to Under-Voltage
Steering wheel:
00883 - Ignition starter switch (clamp S)
Steering wheel:
00888 - Wiper Switch for Intermittent Operation (E22)
Steering wheel:
00895 - Cruise Control Switch (E45)
Auxiliary heater:
00361 - Heating element for additional heating system (Z35)
Auxiliary heater:
01320 - Control Module for Climatronic (J255)
Instrument cluster:
00446 - Function Limitation due to Under-Voltage
Instrument cluster:
00771 - Fuel Level Sensor (G)
Instrument cluster:
00532 - Supply Voltage B+
Instrument cluster:
00562 - Sensor for Oil Level / Temperature (G266)
CAN network gateway:
01331 - Door Control Module: Driver Side (J386)
CAN network gateway:
01334 - Door Control Module: Rear Right (J398)
CAN network gateway:
00470 - Combination comfort Databus in Single Wire
CAN network gateway:
01332 - Door Control Module: Passenger Side (J387)
CAN network gateway:
01333 - Door Control Module: Rear Left (J388)
CAN network gateway:
00470 - Combination comfort Databus in Single Wire
CAN network gateway:
01305 - Databus for Infotainment
CAN network gateway:
01304 - Radio
CAN network gateway:
00532 - Supply Voltage B+
CAN network gateway:
01320 - Control Module for Climatronic (J255)
There's your problem
one of everything. Codes cleared and the new list is a little bit shorter as various things are repaired / reconnected
Engine:
P1635 - Data Bus Powertrain, Missing Message from A/C Controller
Engine:
P0571 - Brake Switch A, Implausible Signal
Engine:
P161A
Engine:
P161B
Engine:
P161C
Engine:
P161D
ABS:
00287 - Right Rear Wheel Speed Sensor (G44)
Airbags:
01222 - Crash Sensor Side Airbag; Passenger Side (G180)
Airbags:
01638 - Crash-Sensor for Side Airbag; Rear Drivers Side (G256)
Airbags:
01217 - Side Airbag Igniter: Front Driver Side (N199)
Airbags:
00588 - Airbag Igniter - Driver Side (N95)
Airbags:
01228 - Airbag Cut-Off Switch for Passenger Side (E224)
Airbags:
02756 - Redundant signal path of Airbag cut-off switch - front passengerside (E224)
Airbags:
00589 - Airbag Ignition Circuit 1 - Passenger Side (N131)
Airbags:
01578 - Airbag Deactivation Warning Lamp, Passengersside (K145)
Power steering:
00778 - Steering Angle Sensor (G85)
Central electronics:
00061 - Footwell Lights
Central electronics:
01504 - Bulb for License-Plate Light (X)
Central electronics:
01333 - Door Control Module: Rear Left (J388)
Central electronics:
01320 - Control Module for Climatronic (J255)
Central electronics:
01332 - Door Control Module: Passenger Side (J387)
Body/convenience system:
01332 - Door Control Module: Passenger Side (J387)
Body/convenience system:
01333 - Door Control Module: Rear Left (J388)
Body/convenience system:
01320 - Control Module for Climatronic (J255)
Auxiliary heater:
00361 - Heating element for additional heating system (Z35)
Auxiliary heater:
01320 - Control Module for Climatronic (J255)
Instrument cluster:
00562 - Sensor for Oil Level / Temperature (G266)
CAN network gateway:
01332 - Door Control Module: Passenger Side (J387)
CAN network gateway:
01333 - Door Control Module: Rear Left (J388)
CAN network gateway:
01320 - Control Module for Climatronic (J255)
CAN network gateway:
01305 - Databus for Infotainment
CAN network gateway:
01304 - Radio
The airbag warnings are because there are no airbags in the car at present, the a/c errors are because it's all disconnected as is the radio, no steering wheel, etc. the loom to the passenger door hasn't been repaired yet so that side is dead but the drivers side is all good
The errors that concern me are the sensor for oil level / temperature, the steering angle sensor, the engine codes and the brake switch as the brake lights were stuck on until I repaired a section of loom and now they don't work.
Still plenty to do. I've got to pull the remainder of the interior out to check the rest of the wiring inside then give it a good bleaching.