U0165low severityNetwork
Lost Communication with Rear HVAC Control Module
on 1997 BMW 328is E36 2.8L I6 M52 · RWD
What this code means
Cannot communicate with the rear climate control zone module.
Symptoms
- Rear A/C not working
- Rear climate controls unresponsive
- No rear heat
- Rear blower not running
Common causes
- Rear HVAC module failure
- CAN bus wiring
- Module power loss
- Fuse blown
- Rear blower motor issue
Diagnostic steps
- Check rear HVAC module fuse
- Test power and ground
- Check CAN wiring
- Test rear blower motor
- Inspect rear climate control panel
Repair notes
Check fuses for rear HVAC system. Rear module wiring runs through pillars.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Bluetooth code reader (~$25)
Veepeak OBDCheck BLE →
Pairs with your phone — reads and clears codes, live data.
Serious DIY (~$100)
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
Shop-grade tablet (~$300+)
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Network codes on this vehicle
CC-ID-181
System Check Failed
CC-ID-207
Central Electronics Failure, Stop Vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High