Low Frequency Initiator
The LFI is located at each vehicle wheel house(F/L, F/R, R/R). An LFI unit is mounted in each wheel well of a vehicle to enable the Receiver unit to determine the vehicle position of each WE for which it has a stored ID code. Using a LIN communition line to each LFI, the Receiver can activate an LFI to send out an LF message and trigger the WE sensor near its location to respond with an RF transmission. By activating the LFI units one at a time, the Receiver can automatically locate the vehicle position of each WE. For fault detection, the LFI will report back its “operating properly” status to the Receiver via the LIN communition line.
This DTC indicates that LF signal generation is stopped when IF antenna ON, LF signal isn＇t stopped when LF antenna OFF. The most likely cause is LFI module failure.
Item | Detecting Condition | Possible cause |
DTC strategy | ● Check pulse | ● Faulty RL LFI module |
Enable conditions | ● IGN ON ● When communication over LIN between ECU and LFI is error free. | |
Threshold value | ● LFI respond with LF signal not generated and localization on position failed. ● LFI respond with LF signal not stopped and localization on position failed. | |
Mil On conditon | ● Active DTC is set |
Set up ＇GDS＇ with ＇GDS TPMS＇.
Select the "CURRENT DATA" function of "TPMS" system.
Monitor the parameters related to ＇Rear Right/ Rear Left LFI＇ on the GDS.
Specification : When the vehicle is driving over 25 km/h and acceleration is more than 5g,
＇LFI No Response Pulse＇ is ＇NO＇.
＇LFI Fail Pulse＇ is ＇NO＇.
＇LFI Pass Pulse＇ is ＇YES＇.
Fig.1) Detect "PASS" pulse from LFI(normal)
Are parameters normal?
▶ Fault is intermittent. It has been repaired and TPMS receiver module memory is not cleared yet.
▶ Go to "Verification of vehicle Repair" procedure.
▶ Go to "Inspection/Repair" procedure.
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.
Thoroughly check all connectors (and connections) for looseness, bending, corrosion, contamination, deterioration, and/or damage.
Has a problem been found?
▶ Repair if necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Component Inspection" procedure.
Substitute with a known-good Rear Left initiator.
Clear DTC.
Drive vehicle at a steady speed for more than 1minute.
Execute "Diagnostic Trouble Codes(DTCs)" mode.
Is ＇C1339＇ present ?
▶ Substitute with a known-good TPMS receiver and check for proper operation.
▶ If the problem is corrected, replace TPMS receiver and then go to "Verification of Vehicle Repair" procedure.
▶ Replace Rear Left initiator and go to "Verification of vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect TPMS exciter or scantool and select "Diagnostic Trouble Codes(DTCs)" mode
Using a TPMS exciter or scantool, Clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
