This is a request for information:

i have come across information that E53s that are wired from the factory for specific option codes are also wired for other codes in the same group, even if the options are not installed.

since I can not verify this information myself, I would like to ask the e53 community at large a favor, to check to see if the specific plugs are present in their vehicles, thus allowing for an easier retrofit installs.

My request would be, during regular course of your maintenance/retrofitting activities, it would be nice if you will look to see if the specific wires/plugs are installed in your car in accordance with the table below.

Level 1 is the vehicle's main harness. if the car has any option from the Level 2, ALL options from the level 2 should be prewired. If the car has any option from Level 3, all options from Level 3 and Level 2 should be prewired...

that theory means that if the car has Navigation, the PDC or SRA are prewired (no relays or modules, just the plugs in the harness). Interestingly enough, it also implies, that if you have PDC, the car should have wires already ran for the Nav retrofit, which I find hard to believe...

according to the same theory, if you have the xenon lights, you would have everything prewired....


It seems that we have options S461 and S496 already confirmed - the plugs are there, the system would need the fuses, relays and the actual heating elements/seats in order to function.

the next relatively easy harness to identify would be the S508 - the PDC wiring next to the battery in the electronics box in the trunk - if we could verify that the PDC wiring is present, that would simplify the reverse camera installs for the folks...


Level 2
S235 - trailer hitch
S502 - SRA (headlight washer)
S508 - PDC
S609 - Nav
S624 through S629 - telephone/radio

Level 3
S248 - steering wheel heater
S261 - rear airbags (interesting, I wonder if this is retrofittable)
S265 - RDC, tire pressure
S461 - backrest heating system in the rear
S496 - seat heating system in the rear
S533 - rear air conditioner
S536 - auxialliary heating system
Level 4
S220 - single axle level control
Level 5
S522 - xenon lights