Telematics Control Module
The vehicle's own mobile connection — its own SIM, its own aerial and its own backup battery. It provides automatic emergency calling (mandatory on new EU type approvals since 2018: after a crash severe enough to deploy the restraints, the vehicle calls the emergency number itself, transmits its position and opens a voice channel whether or not anyone can speak), plus breakdown calling, stolen vehicle tracking, remote locking and preconditioning, and over-the-air updates.
The failure is completely invisible — no symptom, nothing about driving changes — and only becomes apparent at the one moment it was installed for. That is the argument against treating a fault here as "only the connected services".
Two causes are not repairable in the ordinary sense. The internal backup cell, which lets it call after the main battery is destroyed, is a consumable with a service life of several years — a very common finding on a vehicle seven or more years old, and inexpensive. And 2G and 3G networks are being switched off market by market, so a module built for those has nothing to connect to; some manufacturers offered a hardware upgrade and some did not.
Also known as: telematics module, ecall module, emergency call module, connected services module, telematic control unit, telematics unit
Referenced by 8 codes
Codes involving this component (8)
- U0198 Lost Communication With Telematic Control Module High
- U0499 Invalid Data Received From Telematic Control Module High
- U0062 Vehicle Communication Bus D (-) High Moderate
- U0147 Lost Communication With Serial Data Gateway Module B Moderate
- U0197 Lost Communication With Telephone Control Module Moderate
- U0498 Invalid Data Received From Telephone Control Module Moderate
- U0549 Invalid Data Received From Remote Accessory Module Low
- U0555 Invalid Data Received From Remote Start Module Low
Other components in Electrical and Charging
- Data Bus 563
- Battery 218
- Gateway Module 158
- Stability Control Module 122
- Battery Temperature Sensor 115
- Infotainment Head Unit 49
- Alternator 45
- Brake Booster Pressure Sensor 39
- A/C Refrigerant Pressure Sensor 33
- Brake Light Switch 32
- Cruise Control Switch 31
- Ignition Switch 31
- Cooling Fan Relay 28
- Starter Relay 25
- A/C Compressor 25
- Clutch Switch 24
- ECM Power Relay 21
- Roof Antenna Module 19
- Immobiliser 15
- Lighting Driver Control Module 15
- Starter Motor 14
- Transmission Control Module Power Relay 14
- Fuel Pump Relay 13
- Secondary Air Injection Relay 13
- Battery Monitoring Sensor 10
- Driver Information Centre 10
- A/C Evaporator Temperature Sensor 8
- Navigation Control Module 6
- Headlamp Levelling Actuator 6
- Hydraulic Pump Relay 5
- Head-Up Display 2
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
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