Tire Pressure Warning System

TIRE AND WHEEL: TIRE PRESSURE WARNING SYSTEM: C2121/21-C2125/25,C2181/81-C2185/85: No Signal from Transmitter ID1
C2185/85 - Transmitter ID5 not Received (Test Mode DTC)

DESCRIPTION

The tire pressure warning valve and transmitters that are installed in the tire and wheel assemblies measure the tire pressures. 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 turns on.

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 may be unable to receive the signals from the tire pressure warning valve and transmitters, causing a DTC to be 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 the tire pressure warning valve and transmitters for a total of 20 minutes, DTCs will be set.

DTCs from C2121/21 to C2125/25 can be cleared by using the tester or when the tire pressure warning valve and transmitter sends a normal signal. DTCs from C2181/81 to C2185/85 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 C2185/85 are output only in test mode.





NOTICE:
When DTCs C2121/21 to C2125/25 are set, DTC C2173/73 may be set simultaneously. In such cases, troubleshoot C2173/73 first, then troubleshoot DTCs C2121/21 to C2125/25.

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

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* When replacing the tire pressure warning ECU, read the transmitter IDs stored in the old ECU using 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 if the ECU and/or any of the valve and transmitters have been replaced.

PROCEDURE

1. READ OUTPUT DTC (DTC C2173/73)

(a) Turn the ignition switch off.

(b) Connect Techstream to the DLC3.

(c) Turn the ignition switch on (IG) and turn the tester on.

(d) Enter the following menus: Chassis / Tire Pressure Monitor / Trouble Codes.

(e) Read the DTCs.

Result





NOTICE:
When DTC C2173/73 is output, troubleshoot that DTC first. Then troubleshoot DTCs C2121/21 to C2124/24.

B -- GO TO DTC C2173/73 C2173
A -- Continue to next step.

2. CHECK FREQUENCY RECEIVING CONDITION

(a) Check that the vehicle is located in an area such as 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 turn on only in a particular area due to interfering radio frequencies.

(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 transmissions may be interrupted due to the surroundings, or devices installed by the user.

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

3. IDENTIFY TRANSMITTER CORRESPONDING TO DTC

(a) Set the tire pressure to the appropriate specified values Service Precautions.

(b) Turn the ignition switch off.

(c) Connect Techstream to the DLC3.

(d) Turn the ignition switch on (IG) and turn the tester on.

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

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