C2121

TIRE PRESSURE MONITORING: TIRE PRESSURE WARNING SYSTEM: C2121/21-C2124/24, C2131/31-C2134/34, C2181/81-C2184/84: No Signal from Transmitter ID1 in Main Mode

DESCRIPTION

The tire pressure warning valve and transmitter installed in each tire and wheel assembly measures the tire pressure. The measured values are transmitted as radio waves to the tire pressure warning antenna on the body and then set to the tire pressure warning ECU and receiver. 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 assembly comes on. The tire pressure warning ECU stores a DTC when a tire pressure warning valve and transmitter stops transmitting signals.

Under the following conditions below, the tire pressure warning antenna is unable to receive the signals from the tire pressure warning valve 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.

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

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

HINT
When no transmitter ID is received from a tire pressure warning valve and transmitter for a total of 20 minutes while the vehicle speed is more than 8 km/h (5 mph) or no transmitter ID is received from all of the tire pressure warning valve and transmitters for a total of 20 minutes, DTCs are stored.

DTCs from C2121/21 to C2124/24 or C2131/31 to C2134/34 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 ends. DTCs from C2181/81 to C2184/84 are output only in test mode.

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

WIRING DIAGRAM

INSPECTION PROCEDURE

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

PROCEDURE

1. CHECK FREQUENCY RECEIVING CONDITION

(a) Check that the vehicle is not located in an area 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 an area described above, the tire pressure warning light may come 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 frequencies 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 of all the wheels to the specified value Service Precautions.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Check the values by referring to the table below. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor

HINT
*1: It may take about 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 about 2 or 3 minutes to display the updated tire pressure data.
- If "ID Tire Inflation Pressure" data has not changed, reset the tire pressure to the appropriate specified value and rotate the tire 90 to 270 degrees. Then rapidly reduce the tire pressure and recheck it.
- Record the transmitter ID of which "ID Tire Inflation Pressure" data corresponds to each tire.

(i) After confirming that one of "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. SWITCH TIRE PRESSURE WARNING SELECT SWITCH

(a) Switch the tire pressure warning select switch to the other position (MAIN to 2nd or 2nd to MAIN).

(b) Set the tire pressure of all the wheels to the specified value Service Precautions.

(c) Turn the engine switch off.

(d) Connect the Techstream to the DLC3.

(e) Turn the engine switch on (IG).

(f) Turn the Techstream on.

(g) Check the values by referring to the table below. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor

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

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

(i) Check the Data List.

NOTICE:
- It takes about 2 or 3 minutes to display the updated tire pressure data.
- If "ID Tire Inflation Pressure" data has not changed, reset the tire pressure to the appropriate specified value and rotate the tire 90 to 270 degrees. Then rapidly reduce the tire pressure and recheck it.
- Record the transmitter ID of which "ID Tire Inflation Pressure" data corresponds to each tire.

(j) After confirming that one of "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 -- END
A -- Continue to next step.

4. RETURN TIRE PRESSURE WARNING SELECT SWITCH TO ORIGINAL POSITION

NEXT -- Continue to next step.

5. CHECK TRANSMITTER ID

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG).

(d) Turn the Techstream on.

(e) Check the values by referring to the table below. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor

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

(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.

6. REPLACE TIRE PRESSURE WARNING VALVE AND TRANSMITTER

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

NEXT -- Continue to next step.

7. REGISTRATION OF TRANSMITTER ID

(a) Perform registration Registration.

NEXT -- Continue to next step.

8. PERFORM INITIALIZATION

(a) Perform initialization Initialization.

NEXT -- Continue to next step.

9. READ VALUE USING TECHSTREAM (TIRE INFLATION PRESSURE)

(a) Set the tire pressure of all wheels to the specified value Service Precautions.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Check the values by referring to the table below. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor

HINT
- *1: It may take about 2 or 3 minutes until the values are displayed.
- If "ID Tire Inflation Pressure" data has not changed, reset the tire pressure to the appropriate specified value and rotate the tire 90 to 270 degrees. Then rapidly reduce the tire pressure and recheck it.

Result:

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

10. REPLACE TIRE PRESSURE WARNING ANTENNA

(a) Replace the tire pressure warning antenna Removal.

NEXT -- Continue to next step.

11. READ VALUE USING TECHSTREAM (TIRE INFLATION PRESSURE)

(a) Set the tire pressure of all the wheels to the specified value Service Precautions.

(b) Turn the engine switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the engine switch on (IG).

(e) Turn the Techstream on.

(f) Check the values by referring to the table below. Enter the following menus: Chassis / Tire Pressure Monitor / Data List.

Tire Pressure Monitor

B -- REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER Removal

A -- END