Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC B1412: TEL Antenna Disconnected
| DTC Description | DTC |
|---|---|
| B1412 TEL Antenna Disconnected |
DTC (Telematics System)
Check the connectors for poor connections or loose terminals.
- Problem verification
- 1. Clear the DTCs with the HDS.
- 2. Turn the vehicle to the OFF (LOCK) mode and then the ON mode.
- 3. Check for DTCs with the HDS.
DTC Description DTC B1412 TEL Antenna Disconnected Is DTC B1412 indicated?
YES
The failure is duplicated, go to step 2.
NO
Intermittent failure, the system is OK at this time.
- Determine possible failure area (roof antenna, others)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Roof antenna connector A (4P) - 3. Turn the vehicle to the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Roof antenna connector A (4P): disconnected Test point 1 Roof antenna connector A (4P) No. 2 Test point 2 Body ground Is there about 3.0 V?
YES
NO
Go to step 3.
- Open wire check (TEL line)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Telematics control unit connector C (4P) - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Roof antenna connector A (4P): disconnected Telematics control unit connector C (4P): disconnected Test point 1 Roof antenna connector A (4P) No. 2 Test point 2 Telematics control unit connector C (4P) No. 1 - Refer to: Telematics Control Unit Connector For Inputs And Outputs (With Auto Idle Stop System) (2015-17) , or Telematics Control Unit Connector for Inputs and Outputs (Without Auto Idle Stop System) (2015-17), or Telematics Control Unit Connector for Inputs and Outputs (2018-19) Is there continuity?
YES
Replace the telematics control unit .
NO
There is an open in the wire between the roof antenna and the telematics control unit. Replace the affected antenna lead.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.