【TPMS Sensor : Wheel Electronic (WE) Sensor
Unit】
Each vehicle wheel is
fitted with a Wheel Electronic (WE) sensor unit attached to the valve on
the inside of the wheel. The WE unit is powered with a self-contained
battery utilizing a high temperature rated CR (Manganese Dioxide Lithium)
chemistry. The operating voltage range for the WE module is 2.2 Vdc to 3.6
Vdc, and the operating temperature range is -40 °F to 257 °F(-40 °C ~125
°C). The WE measures tire pressure, temperature, and acceleration
periodically. The pressure, temperature, and acceleration information is
converted to digital form within the MCU inside the WE
sensor.
The WE sensor is
equipped with a Radio Frequency (RF) transmitter circuit which is used to
periodically broadcast information from inside the tire. All WE sensor
units operate on the same RF channel frequency, and each broadcast message
includes pressure and temperature data, a unique ID code, operating state
data, status information, and digital error-detection data.
The pressure measured by
the WE sensor is an absolute pressure value. The pressure measurement
range is 100 kPa (14.5 psi) to 450 kPa (65.27 psi). The acceleration data
is used within the WE sensor to determine whether the vehicle is moving or
stationary. The acceleration status is the decision maker within the WE
module that determines if the tire is moving or stationary. This
measurement is used within the WE module to enable different operating
modes depending on the status of the acceleration value. Over the fully
specified operating temperature range, if the acceleration measurement is
greater than or equal to 20G, the WE module assumes the tire is
moving.
The basic operation of
the L/L WE sensor is to transmit 3 frames every 3 minutes in both
stationary and rolling modes.
This DTC indicates that
the Front Right WE sensor battery voltage is below 2.2Vdc. The most likely
cause is battery passing it’s expected life / sensor failure.
Item
|
Detecting
Condition
|
Possible cause
|
DTC
strategy
|
| •
|
Check RF message from FR
sensor | |
| •
|
FR WE sensor battery
low |
|
Enable
conditions
|
|
Threshold
value
|
| •
|
FR WE sensor battery voltage <
2.2V |
|
Diagnosis
time
|
| •
|
Within 2 minutes during IGN
ON | |
| 1. |
Connect 'TPMS exciter' or scantool to Data
Link Connector(DLC). |
| 2. |
Select "TPMS DIAGNOSIS"
mode. |
| 3. |
Select the "FULL" mode of "TPM DATA VALUES"
function. |
| 4. |
Monitor the parameter of "S2 BATTERY" on the
'TPMS exciter' or scantool.
Specification
: 'S2 BATTERY' is
'NORMAL'.
|
|
| 5. |
Is parameter within
specifications?
|
|
▶ Fault is
intermittent. It has been repaired and TPMS receiver module
memory is not cleared yet.
▶ Go to
"Verification of vehicle Repair" procedure.
|
|
|
▶ Replace
Front Right WE sensor and register sensor ID with 'TPMS
exciter'.
▶ Go to "Verification of
Vehicle Repair"
procedure.
|
|
| Verification of Vehicle
Repair |
After a repair, it is
essential to verify that the fault has been corrected.
| 1. |
Connect TPMS exciter or scantool and select
"Diagnostic Trouble Codes(DTCs)"
mode |
| 2. |
Using a TPMS exciter or scantool, Clear
DTC. |
| 3. |
Operate the vehicle within DTC Enable
conditions in General information. |
| 4. |
Are any DTCs present ?
|
|
▶ Go to the
applicable troubleshooting procedure.
|
|
|
▶ System
performing to specification at this
time.
|
|
