C1240
C1240General Description:
General Description
This transmitter is a transmitter device with tire valve, which is mounted in the valve hole of the wheel rim and transmits the pressure and temperature inside the tire, the battery voltage of the transmitter, and the tire identification code (ID) at normal and abnormal condition with the radio wave (RF) that conforms to the used area. Also this device has a countermeasure function such as the random delay of transmission time so that the RF signal from each tire will not interfere due to simultaneous transmission. Wheel sensors shall support usage on steel or aluminum rims. Sensor transmissions continue when sensor status is 'Normal Fixed State'. Sensor transmissions stop when sensor status is 'Storage State' or the sensor battery runs out. The transmitter should transmit data at vehicle speeds between 0 mph (0 kph) and 186 mph (300 kph). Operating Temperature Range is -40 to 248 °F (-40 to 120 °C). Transmitter shall enter thermal shutdown once the measured temperature is greater than or equal to 257 °F (125 °C). The accuracy of the sensor is 23 to 44.6 °F (-5 to 7 °C) at this temperature. The sensor shall exit thermal shutdown once the temperature is less than or equal to 212 °F (100 °C). The transmitter shall have the capability to measure the internal battery voltage as an indicator of the end of life of the sensor. Since the unit is sealed, this parameter cannot be verified with a production unit. [Tire Pressure Monitoring] When 4 sensors have been learned as road wheels, it shall not be possible to learn new road wheel sensors on the same Ignition cycle. In normal mode low line, tire pressure and temperature shall be transmitted every 3 minutes 20 s nominally independent of vehicle operation. Monitoring shall be every 20 s. If sensor detects rapid deflation, then RF messages will be transmitted every 4 s for 1 minute duration. Communication from wheel sensors shall be via RF at a frequency of 315 MHz, 5 kBaud. Tire pressure measurement tolerance shall be ± 7 kPa from 32 to 122 °F (0 to 50 °C) and ± 17.5 kPa from -40 to 248 °F (-40 to 120 °C) with a range of 100 to 450 kPa. Tire temperature measurement tolerance shall be ± 37.4 °F ( ± 3 °C) from -4 to 158 °F (-20 to 70 °C) and to ± 41 °F ( ± 5 °C) from -40 to 248 °F (-40 to 120 °C).
DTC Description
This DTC indicates that the Vehicle speed signal is not inputted normally. The most likely cause is speed sensor failure/ speed signal line's open.
DTC Detecting Condition:
Schematic Diagram:
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.
3. Has a problem been found?
YES - Repair if necessary and then go to "Verification of Vehicle Repair" procedure
NO - Go to "Signal Circuit Inspection" procedure
Signal Circuit Inspection
Check Open
1. Ignition "OFF"
2. Disconnect ABS (ESC) ECU connector and TPMS receiver connector.
3. Measure resistance between terminal "12" of ABS (ESC) ECU harness connector and terminal "6" of TPMS receiver harness connector.
Specification : Approx. 0 ohms
4. Is the measured resistance within specifications?
YES - Faulty Vehicle speed sensor may cause this DTC. Substitute with a known-good component and check for proper operation. If problem is corrected, it's failure should cause this DTC. After doing an appropriate repair, Go to "Verification of Vehicle Repair" procedure.
NO - Repair as necessary in speed signal circuit and then 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?
YES - Go to the applicable troubleshooting procedure.
NO - System performing to specification at this time.