C2121

Circuit Description
When the diagnostic procedures indicate that receiver replacement is necessary, program the service replacement receiver to the vehicle's TPM sensors. Each sensor's unique identification code can be programmed into the receiver's memory. After the program mode is entered, each sensor must transmit its identification code in sequence. DTC C2121 is set at the time of manufacture and will automatically be cleared when the programming procedure is properly completed. This DTC can only be set once during the life of the receiver.

Conditions for Setting the DTC
This DTC is automatically set at the time of manufacture. No TPM sensors are programmed in the receiver's memory.

Action Taken When the DTC Sets
- Stores a DTC C2121 in the receiver's memory
- No driver warning message will be display for this DTC.
- The IPC will default to display all tire pressure as XXX kPa (XX psi).

Conditions for Clearing the DTC
The receiver clears this DTC automatically when TPM sensor programming is complete.

Diagnostic Aids
- The service replacement receivers will have DTCs B2805 and C2121 stored in the receiver's memory and will not clear until the receiver is properly programmed. When diagnostic procedures indicate that receiver replacement is necessary, program all TPM sensors and RFA transmitters to the replacement receiver.
- Check that a service replacement receiver was not installed without programming the TPM sensors to that receiver.
- Clear the receiver's diagnostic memory before road testing the vehicle whenever a TPM sensor is replaced in order to avoid reading the original DTC stored in the memory.


Test Description
The numbers below refer to the Step numbers on the diagnostic table:
2. This test checks if the IPC can enter the TIRE TRAINING mode. If the display is blank, or if the DIC buttons do not respond when pressed, refer to IPC Diagnostic System Check. Testing and Inspection
3. This test determines if the TPM sensors can properly transmit their identification codes. (If the horn did not sound during the test, the receiver was unable to receive a TPM sensor identification code.)
4. This test determines if all of the TPM sensors are on the vehicle and undamaged.
5. This test checks if the TPM sensors corrected the malfunction.
6. This test will determine if the RFA transmitters are currently programmed. If the RFA transmitters are not programmed, the receiver will have a DTC B2805 stored in the memory.