Lost Communication with Rear HVAC Control Module
2002-2002 Cadillac Escalade 6.0L V8
The 2002 Cadillac Escalade is equipped with a 6.0L V8 engine. Below you'll find detailed u0165 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
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.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0006High Speed CAN Communication Bus (-) Open
- U0007High Speed CAN Communication Bus (-) Low
- U0008High Speed CAN Communication Bus (-) High
- U0009High Speed CAN Communication Bus Shorted Together
- U0010Medium Speed CAN Communication Bus
U0165 on Other Vehicles
Common Questions
What does code U0165 mean on a 2002-2002 Cadillac Escalade?
U0165 stands for "Lost Communication with Rear HVAC Control Module". Cannot communicate with the rear climate control zone module.
What are the symptoms of U0165 on a Cadillac Escalade?
Common symptoms of U0165 include: Rear A/C not working, Rear climate controls unresponsive, No rear heat, Rear blower not running.
What causes U0165 on a 2002-2002 Cadillac Escalade?
Common causes of U0165 include: Rear HVAC module failure, CAN bus wiring, Module power loss, Fuse blown, Rear blower motor issue.
Last updated: March 2026