C2121

TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM: C2121/21-C2124/24, C2181/81-C2184/84: No Signal from Transmitter ID1 in Main Mode

DESCRIPTION

The tire pressure warning valve and transmitters installed in the tire and wheel assemblies measure the air pressure of the tires. The measured values are transmitted to the tire pressure warning antenna and receiver on the body as radio waves and then sent to the tire pressure warning ECU. The ECU compares the measured air pressure values with the air pressure threshold. When the measured air pressure value is less than this threshold, the warning light in the combination meter illuminates.

The tire pressure warning valve and transmitters constantly send radio waves to the tire pressure warning antenna and receiver.

Under the conditions below, the tire pressure warning antenna and receiver is unable to receive the signals from the tire pressure warning valves and transmitters, and a DTC is stored.

- Facilities or devices that use similar radio frequencies are located in the vicinity of the vehicle.

- Devices using similar radio frequencies are used in the vehicle.

- An ID of the tire pressure warning valve and transmitter is mistyped during registration.

- A tire, wheel and/or transmitter from a different vehicle is installed.

HINT
These DTCs are detected when no signals are received for 20 minutes or more, after a vehicle speed of 8 km/h (5 mph) or more is detected and no signals are still received for 20 minutes or more.

DTCs from C2121/21 to C2124/24 can only be cleared by using the Techstream. DTCs from C2181/81 to C2184/84 can be cleared when the transmitter in the tire pressure warning valve and transmitter sends a forced transmission signal or test mode (signal check mode) ends. DTCs from C2181/81 to C2184/84 are output only in test mode (signal check mode).

HINT
It is necessary to perform this procedure in order to identify the malfunctioning tire pressure warning valve and transmitter because it cannot be identified by only the output DTCs.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
- When replacing the tire pressure warning ECU, read the IDs stored in the old ECU using the Techstream and write them down before removal.
- It is necessary to perform initialization Initialization after registration Registration of the transmitter IDs into the tire pressure warning ECU after the ECU and/or valve and transmitter has been replaced.

PROCEDURE

1. CHECK FREQUENCY RECEIVING CONDITION

(a) Check if the vehicle is located in areas such as the ones described below:

(1) Facilities or devices that use similar radio frequencies are located in the vicinity of the vehicle.

HINT
If the vehicle is located in areas described above, the tire pressure warning light may turn on only in a particular area.

(2) Devices using similar radio frequencies are used in the vehicle.

OK:

Facilities, or devices that use similar radio frequencies are not located in the vicinity of the vehicle.

HINT
Radio frequency may be interrupted due to surroundings or devices installed by the user.

NG -- CHECK IF ANY DEVICE IS INSTALLED BY USER
OK -- Continue to next step.

2. IDENTIFY TRANSMITTER CORRESPONDING TO DTC

(a) Set the tire pressure to the appropriate specified values Component Tests and General Diagnostics.

(b) Turn the power switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the power switch on (IG) and turn the Techstream on.

(e) Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

(f) Check the values by referring to the table below.

Tire Pressure Monitor

HINT
*: It may take up to 2 or 3 minutes until the values are displayed.

(g) Rapidly reduce the tire pressure for each wheel at least 40 kPa (0.4 kgf/cm2, 5.8 psi) within 30 seconds.

(h) Check the DATA LIST.

NOTICE:
- It takes up to 2 or 3 minutes to display the updated tire pressure data.
- If no "ID Tire Inflation Pressure" data has changed, reset the tire pressure to the appropriate specified value and rotate the tire 90 to 270°. Then rapidly release the tire pressure and recheck it.
- Record the "ID Tire Inflation Pressure" data transmitter ID that corresponds to each tire.

(i) After confirming that the "ID Tire Inflation Pressure" data for one tire (ID1 to ID4) has changed, repeat this procedure one by one. Identify the transmitter that corresponds to the DTC.

Result

B -- CHECK TRANSMITTER ID

C -- END
A -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ECU - RECEIVER)

(a) Disconnect the F61 ECU connector.

(b) Disconnect the L26 receiver connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK TRANSMITTER ID

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (IG) and turn the Techstream on.

(d) Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

(e) Check the values by referring to the table below.

Tire Pressure Monitor

(f) Check the ID number on the identified transmitter by removing it from the tire and wheel.

Text in Illustration

(g) Confirm that the ID number on the transmitter and recorded transmitter ID match.

Result

B -- REGISTRATION OF TRANSMITTER ID
A -- Continue to next step.

5. REPLACE TIRE PRESSURE WARNING VALVE AND TRANSMITTER

(a) Replace the tire pressure warning valve and transmitter Removal.

NEXT -- Continue to next step.

6. REGISTRATION OF TRANSMITTER ID

(a) Perform registration Registration.

NEXT -- Continue to next step.

7. PERFORM INITIALIZATION

(a) Perform initialization Initialization.

NEXT -- Continue to next step.

8. CONFIRM TIRE INFLATION PRESSURE (DATA LIST)

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (IG) and turn the Techstream on.

(d) Enter the following menus: Chassis / Tire Pressure Monitor/ Data List.

(e) Check the values by referring to the table below.

Tire Pressure Monitor

HINT
- *: It may take up to 2 or 3 minutes until the values are displayed.
- If no "ID Tire Inflation Pressure" data has changed, reset the tire pressure to the appropriate specified value and rotate the tire 90 to 270°. Then rapidly release the tire pressure and recheck it.

Result

B -- END
A -- Continue to next step.

9. REPLACE TIRE PRESSURE WARNING ANTENNA AND RECEIVER

(a) Replace the tire pressure warning antenna and receiver Removal.

NEXT -- Continue to next step.

10. CONFIRM TIRE INFLATION PRESSURE (DATA LIST)

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (IG) and turn the Techstream on.

(d) Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

(e) Check the values by referring to the table below.

Tire Pressure Monitor

B -- REPLACE TIRE PRESSURE WARNING ECU Removal

A -- END