On-Board Diagnostic System Description

On-Board Diagnostic System Description

Self-Diagnosis Function

BCM diagnoses conditions of the TPMS component parts (whether or not there is any abnormality) all the time and indicates the results (warning of abnormality occurrence) through the low tire pressure warning light as described.

- When ignition switch is turned ON, low tire pressure warning light (1) lights for 2 seconds to check its warning light and its circuit.
- When no abnormality has been detected (the system is in good condition), low tire pressure warning light turns OFF after 2 seconds.
- When BCM receives the signal indicating the tire pressure and judges it as lower than the specified value (lower than 190 kPa), it causes the low tire pressure warning light to light up and stores the DTC in its EEPROM.
- When tire pressure sensor ID code is not registered in BCM, it causes low tire pressure warning light to light up and stores the DTC in its EEPROM.
- When BCM cannot identify the signals indicating the tire air pressure, function code or ID code sent from each tire pressure sensor, or BCM cannot receive vehicle speed signal from ECM, it makes the low tire pressure warning lights up after blinks for 75 seconds and stores the DTC in its EEPROM.
Also, BCM judges whether or not the tire pressure sensor is functioning properly by using the function code indicating the condition of the tire pressure sensor. When it detects an abnormality, it also makes the low tire pressure warning lights up after blinks for 75 seconds and stores the DTC in its EEPROM.

- When CAN communication between BCM and combination meter fails, however, it is combination meter that makes low tire pressure warning lights up after blinks for 75 seconds.