DIAGNOSIS
TSB Revision
KEYLESS OPERATION SYSTEM (KOS)
42B-95
STEP 1. Using scan tool MB991958, diagnose the CAN bus
line.
Use scan tool to diagnose the CAN bus lines.
Q: Is the check result normal?
YES : Go to Step 2.
NO : Repair the CAN bus lines (Refer to GROUP 54C
−
CAN Bus Diagnostics table
P.54C-17
). On
completion, go to Step 2.
STEP 2. Diagnostic trouble code check
(1) Turn the ignition switch to the "LOCK" (OFF) position.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC C1608 set?
YES : Replace the KOS-ECU and register the ID codes
(Refer to
P.42B-188
). Then go to Step 3.
NO : The procedure is complete.
STEP 3. Diagnostic trouble code check
(1) Turn the ignition switch to the "LOCK" (OFF) position.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC C1608 set?
YES : Start over at Step 1.
NO : The procedure is complete.
DTC C1900: No registration
CAUTION
If there is any problem in the CAN bus lines, an incorrect
diagnostic trouble code may be set. Prior to this diagno-
sis, diagnose the CAN bus lines (Refer to GROUP 54C,
Trouble code diagnosis
P.54C-17
).
.
DTC SET CONDITION
When the ID registration information of the TPMS transmitter is
not stored in KOS-ECU, and/or when KOS-ECU is replaced
with a new one, this code is set. If the ID registration mode is
terminated forcibly or time-out after one or more TPMS trans-
mitters are registered in the ID registration mode, the ID infor-
mation in the KOS-ECU is erased, and this diagnostic trouble
code is set.
.
TROUBLESHOOTING HINTS
The most likely causes for this DTC to set are:
• Damaged wiring harness and connector
• Malfunction of TPMS transmitter