U0933low severityNetwork
Lost Communication With Cellular/Telematics Module
on 2021 Toyota C-HR 2.0L I4 · FWD
What this code means
The vehicle's network has lost communication with the telematics or connectivity module. This typically disables emergency calling, remote services, and connected features.
Symptoms
- Loss of connected services
- Telematics warning message
- Emergency call feature inoperative
Common causes
- Faulty telematics module
- Blown fuse or bad power supply to module
- Damaged CAN bus wiring or connectors
- Corroded or loose module ground
Diagnostic steps
- Scan all modules for related U-codes
- Check power and ground at telematics module
- Inspect CAN bus wiring for damage
- Verify module communication with scan tool
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Budget handheld~$40
ANCEL AD410 →
No-phone-needed handheld — reads, clears, live data, freeze frame.
✓ ANCEL official store
Serious DIY~$100
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
SHOP FAVORITEShop-grade tablet~$300
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
✓ Autel official store
Pro diagnostics$1,500+
Autel MaxiSys MS906 Pro →
Full-system pro platform — topology mapping, ECU coding, the works.
✓ Autel official store
As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Network codes on this 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
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus