DESCRIPTION
The tire pressure warning valve and transmitters that are installed in the tire and wheel assemblies measure the tire 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 tire pressure values with the tire pressure threshold. When the measured tire 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. The stored DTC is cleared when the signal transmission is resumed.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2111/11 C2112/12 C2113/13 C2114/14 C2115/15 | Tire pressure warning valve and transmitters stop transmitting signals | Tire pressure warning valve and transmitter Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
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 1
The tire pressure warning valve and transmitters that are installed in the tire and wheel assemblies measure the tire 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 tire pressure values with the tire pressure threshold. When the measured tire 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 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: DTCs from C2121/21 to C2125/25 can only be cleared by using the Techstream. 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.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2121/21 C2122/22 C2123/23 C2124/24 C2125/25 | Following condition (a) or (b) is met: 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 valve 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. When all conditions below are met: Tire pressure warning valve and transmitter is not in stop mode. Transmitter IDs are not received from tire pressure warning valve 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 C2185/85 | Test mode procedure is performed. | Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
Note. When DTCs C2121/21 to C2125/25 are set, DTC C2179/79 may be set simultaneously. In such cases, troubleshoot C2179/79 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.
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 information 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 Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2126/26 | After all ID registration is completed, until all tire pressure warning valve and transmitter IDs are received by tire pressure warning ECU. | ID registration failure Tire pressure warning valve and transmitter Tire pressure warning antenna and receiver Harness or connector Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
HINT
The purpose of this DTC is to help prevent delivering a vehicle that has incorrectly registered IDs. After all IDs are registered, DTC C2126/26 is detected, and the tire pressure warning light blinks for 1 minute and then comes on. If the tire pressure warning light does not turn off after a little while, IDs may be incorrectly registered.
When the internal circuit of a tire pressure warning valve and transmitter is malfunctioning, one of these DTCs is output.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2141/41 C2142/42 C2143/43 C2144/44 C2145/45 | 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 parts. | Tire pressure warning valve and transmitter Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
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 Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2165/65 C2166/66 C2167/67 C2168/68 C2169/69 | Temperature inside the tire exceeds 119°C (246.2°F) more than specified times. | Tires Tire pressure warning valve and transmitter Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
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 a transmitter ID code is not registered in the ECU, a DTC is output.
| DTC Code | 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 |
DTC DETECTION CONDITION CHART
This DTC is stored when referencing data becomes impossible due to an internal malfunction in the ECU.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2176/76 | Malfunction in the tire pressure warning ECU internal circuit. | Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
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 standard tire pressure are installed; 4) the tires are rotated; or 5) a new vehicle is delivered.
| DTC Code | 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 |
DTC DETECTION CONDITION CHART
The tire pressure warning ECU exchanges speed signals and warning light signals with the combination meter via CAN communication.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2179/79 | Data communication is interrupted for a continuous period of 10 seconds. | Combination meter CAN communication system Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
The tire pressure warning ECU receives speed signals from the combination meter via CAN communication. 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 Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| C2191/91 | Test mode procedure is performed | Combination meter CAN communication system Tire pressure warning ECU |
DTC DETECTION CONDITION CHART
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 2
If the ECU detects trouble, the tire pressure warning light blinks (turns on after blinking for 1 minute) and the tire pressure monitor is canceled at the same time. At this time, the ECU records a DTC in the memory.
Connecting terminals TC and CG of the DLC3 makes the tire pressure warning light blink and output the DTC.
This is the power source for the tire pressure warning ECU.
Scheme 3
DTC output mode is set by connecting terminals 13 (TC) and 4 (CG) of the DLC3. The DTCs are indicated by the blinking of the tire pressure warning light.
Scheme 4
HINT
When each warning light blinks continuously, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
Scheme 5
- CHECK HARNESS AND CONNECTOR (DLC3 - ECM AND BODY GROUND) Disconnect the A13 ECM connector. Measure the resistance according to the value(s) in the table below. Standard resistance STANDARD RESISTANCE REFERENCE CHART Tester Connection Condition Specified Condition L31-13 (TC) - A13-21 (TC) Always Below 1 ohms L31-13 (TC) or A13-21 (TC) - Body ground Always 10 kohms or higher L31-4 (CG) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
- INSPECT DLC3 (TC VOLTAGE) Connect the A13 ECM connector. Measure the voltage according to the value(s) in the table below. Standard voltage STANDARD VOLTAGE REFERENCE CHART Tester Connection Switch Condition Specified Condition L31-13 (TC) - L31-4 (CG) Engine switch on (IG) 10 to 14 V NG: REPLACE ECM (See «REMOVAL»(/lexus/ls/iv-2006-2012/remont/testing-diagnostics/#engine-control-system) ) OK: CHECK ECU POWER SOURCE CIRCUIT (See «ECU POWER SOURCE CIRCUIT» )
Scheme 6
See also:
• DIAGNOSIS SYSTEM
• DTC CHECK/CLEAR
• REMOVAL
• REMOVAL