VAG 01336 identifies a problem involving the comfort-system data bus. A single-wire description refers to a particular network’s degraded operating state; it is not a general description of every CAN network or an instruction to modify its wiring.
A network fault can appear in several places
Save a complete vehicle scan so the reporting modules can be compared. One controller may report a missing message because another module has lost power or because the connecting network has a fault. Replacing the module that stores the code first can miss the cause.
Ross-Tech’s reference includes wiring, connected controllers and gateway-coding checks. It gives a Passat 3B example involving comfort and door electronics, with water damage among the possible findings. That model-specific note should guide a matching investigation rather than be assumed on every vehicle. 01336 technical reference.
Questions worth answering
- Which body functions fail at the same time?
- Which modules remain reachable during the fault?
- Did the problem follow retrofit equipment, coding work or water ingress?
- Does the full fault text identify single-wire operation or another condition?
Network testing must follow the correct architecture and manufacturer procedure. Do not apply a universal resistance or voltage rule to every network and assume the result proves a module is faulty.
AXION network enquiries
Contact AXION with the scan and any network-test findings. Vehicle diagnosis is often necessary to establish which unit or wiring section requires attention. Our network and gateway collection provides further context.
Reviewed September 2026. Use the complete manufacturer-specific fault description and vehicle repair information.