DESCRIPTION
The tire pressure warning valves and transmitters that are installed in the tire and wheel assemblies measure the air pressures 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 turns on. The tire pressure warning ECU stores a DTC when the tire pressure warning valve and transmitter stops transmitting signals. At this time, forcibly transmit the signals by releasing the tire pressure rapidly. The stored DTC is cleared when the signal transmission is resumed.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2111/11 C2112/12 C2113/13 C2114/14 | Tire pressure warning valves and transmitters stop transmitting signals | Tire pressure warning valve and transmitter Tire pressure warning ECU |
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.
Scheme 19
The tire pressure warning valves and transmitters that are 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 turns on.
The tire pressure warning valves 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.
- 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 valves and transmitters for a total of 20 minutes, DTCs are set.
DTCs from C2121/21 to C2124/24 can only be cleared by using the tester. 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.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2121/21 C2122/22 C2123/23 C2124/24 | Following condition (a) or (b) is met: (a) When all conditions below are met: Tire pressure warning valve and transmitter is not in stop mode. Any transmitter ID is not received from tire pressure warning valves and transmitters. For 20 minutes or more, vehicle speed is more than 8 km/h (5 mph) or no vehicle speed signal or engine speed signal is received. (b) When all conditions below are met: Tire pressure warning valve and transmitter is not in stop mode. No transmitter ID is received from tire pressure warning valves and transmitters for 20 minutes or more. | Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
| C2181/81 C2182/82 C2183/83 C2184/84 | Test mode procedure is performed. | Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
Note. When DTCs C2121/21 to C2124/24 are set, DTC C2173/73 may be set simultaneously. In such cases, troubleshoot C2173/73 first, then troubleshoot DTCs C2121/21 to C2124/24.
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.
After all IDs are registered, DTC C2126/26 is set in the tire pressure warning ECU and the tire pressure warning light blinks for 1 minute and then comes on.
When the tire pressure warning ECU successfully receives radio waves from all the transmitters whose IDs are stored in the ECU, DTC C2126/26 is deleted and the tire pressure warning light goes off.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2126/26 | After ID registration is completed, ECU does not receive radio waves from transmitters whose IDs are stored in ECU. | ID registration failure Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
HINT
If the IDs stored in the tire pressure warning ECU differ from the transmitter IDs, DTC C2126/26 is set. Check that the IDs in the ECU are the same as the transmitter IDs.
The tire pressure warning valves and transmitters that are 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 turns on.
When the internal circuit of a tire pressure warning valve and transmitter is malfunctioning, one of these DTCs is output.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2141/41 C2142/42 C2143/43 C2144/44 | If an "ERROR" signal is received 3 times consecutively, the tire pressure warning valve and transmitter will be judged as defective and a DTC will be output. This will happen in situations where the inflation pressure is outside the range -100 to 537.5 kPa (-1 to 5.4 kgf/cm 2 , -14 psi to 78 psi), the temperature inside the tire is outside the specified range -40 to 120°C (-40 to 253°F), or an error occurs in the tire pressure warning valve and transmitter or the surrounding area. | Tire pressure warning valve and transmitter Tire pressure warning ECU |
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.
Each tire pressure warning valve and transmitter measures the internal temperature of its tire as well as tire pressure, and transmits the information to the tire pressure warning ECU along with the transmitter ID. If the measured temperature is out of the specified range, the tire pressure warning ECU recognizes it as a malfunction and outputs DTCs, and the tire pressure warning light blinks for 1 minute and then remains on.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2165/65 C2166/66 C2167/67 C2168/68 | Temperature inside the tire exceeds 119°C (246.2°F) more than a specified amount of time. | Tires Tire pressure warning valve and transmitter Tire pressure warning ECU |
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.
The IDs of each tire pressure warning valve and transmitter are registered in the tire pressure warning ECU.
When the ECU detects that transmitter ID code is not registered in the ECU, a DTC is output.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2171/71 | Transmitter ID code is not registered. (When an ID code is unregistered for 3 minutes or more) | Tire pressure warning ECU |
The tire pressure warning ECU receives a vehicle speed signal from the combination meter and an engine speed signal from the ECM. The tire pressure warning ECU uses these signals to detect DTCs C2121/21 to C2124/24 (No Signal from Transmitter in Main Mode) and DTC C2177/77 (Initialization not Completed).
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2173/73 | Following condition (a) or (b) is met for a total of 15 minutes: (a) No engine speed signal while vehicle speed is 8 km/h (5 mph) or more (b) No vehicle speed signal while engine speed is a specified value | Combination meter ECM Harness or connector Tire pressure warning ECU |
HINT
This DTC is set at the same time as DTCs C2121/21 to C2124/24 are being set.
Scheme 20
The signals 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.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2176/76 | Malfunction in the tire pressure warning ECU internal circuit. | Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
Scheme 21
Initialization is necessary if one of the following occurs: 1) the ECU is replaced; 2) the tire pressure warning valve and transmitter is replaced; 3) tires with a different tire standard pressure are installed; 4) the tires are rotated; or 5) a new vehicle is delivered.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2177/77 | When all conditions below are met: During initialization Tire pressure warning valve and transmitter is not in stop mode Signal is not received from tire pressure warning valve and transmitter for 20 minutes or more Vehicle speed is more than 8 km/h (5 mph) for a total of 20 minutes | Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Tire pressure warning ECU Harness or connector |
The tire pressure warning ECU receives a vehicle speed signal from the combination meter. This DTC is stored upon entering test mode, and cleared when a vehicle speed signal of 20 km/h (12 mph) is detected for 3 seconds or more. This DTC is output only in test mode.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2191/91 | Vehicle speed signal circuit malfunction | Combination meter Vehicle speed sensor Harness or connector Tire pressure warning ECU |
Scheme 22
The tire pressure warning ECU receives an engine speed signal from the ECM. This DTC is stored upon entering test mode, and cleared when an engine speed signal of 1000 rpm or more is detected for 3 seconds or more. This DTC is output only in test mode.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2194/94 | Engine speed signal circuit malfunction | ECM Harness or connector Tire pressure warning ECU |
Scheme 23
Initialization can be started by pressing the tire pressure warning reset switch and holding it for 3 seconds or more.
If the ECU receives the signal from the switch, the tire pressure warning light blinks 3 times (1 second on, 1 second off).
Scheme 24
If the tire pressure warning ECU detects a disconnected connector or an open circuit between the tire pressure warning ECU and combination meter, the tire pressure warning light turns off 10 seconds after the ignition switch is turned ON, blinks for 1 minute, and then remains on.
Scheme 25
This is the power source for the tire pressure warning ECU.
Scheme 26
DTC output mode is set by connecting terminals TC and CG of the DLC3. The DTCs are indicated by the blinking of the tire pressure warning light.
Scheme 27
HINT
When each warning light continues blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
See also:
• INSPECTION - Step 1