ON-BOARD DIAGNOSTIC SYSTEM [INSTRUMENT CLUSTER (TPMS)]

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Note

•  Only the direct Tire Pressure Monitoring System (TPMS)-related information is described in this section.

Outline

―  A malfunction detection function that detects abnormalities in input/output signals when the ignition switch is at the ON position.

―  A PID/data monitor function that reads out specified input/output signals.

―  PID/data monitor access

―  DTC clear using the display screen of the diagnostic tester

Block diagram

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Function

Malfunction detection function

•  The malfunction detection function detects malfunctions in the input/output signal system of the instrument cluster when the ignition switched ON or driving the vehicle.

Malfunction display function

•  When the malfunction detection function detects a malfunction, the Tire Pressure Monitoring System (TPMS) warning light illuminates to alert the driver.

•  Using the external tester communication function, DTCs can be output to the DLC-2 via the CAN line. At the same time, malfunction detection results are sent to the memory function and fail-safe function.

Memory function

•  The memory function stores DTCs of malfunctions in input/output signal systems. With this function, once a DTC is stored it is not cleared after the ignition switch has been switched OFF, even if the malfunctioning signal system has returned to normal.

•  Since the instrument cluster has a built-in non-volatile memory, DTCs are not cleared even if the battery is removed. Therefore, it is necessary to clear the memory after performing repairs. Refer to the Workshop Manual for the DTC clearing procedure.

DTC table

Status byte for DTC

•  The status byte is the two-digit code (two digits after hyphen (-)) after the seven-digit DTC.

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•  The status byte is a code which indicates the pending code, current/past malfunction status, or warning illumination status.

•  The status byte can be read by performing a CMDTC self test using the Mazda Modular Diagnostic System (M-MDS).

•  For details on the status byte, refer to the explanation on the M-MDS when reading the DTC.

Fail-safe function

•  When the malfunction detection function determines a malfunction, the Tire Pressure Monitoring System (TPMS) warning light illuminates to alert the driver. At this time, the fail-safe function controls as indicated in the fail-safe function table.

Fail-safe function table

PID/data monitor function

•  The PID/data monitor function is used for optionally selecting input/output signal monitor items preset in the instrument cluster and reading them out in real-time.

Monitor item	Unit/operation	Definition
ID_WU1	—	Registered wheel unit ID (wheel unit No.1)
ID_WU2	—	Registered wheel unit ID (wheel unit No.2)
ID_WU3	—	Registered wheel unit ID (wheel unit No.3)
ID_WU4	—	Registered wheel unit ID (wheel unit No.4)
WU1_ERR_P	Normal/Error	Tire pressure status (wheel unit No.1)
WU2_ERR_P	Normal/Error	Tire pressure status (wheel unit No.2)
WU3_ERR_P	Normal/Error	Tire pressure status (wheel unit No.3)
WU4_ERR_P	Normal/Error	Tire pressure status (wheel unit No.4)
WU1_ERR_T	Normal/Error	Tire air temperature status (wheel unit No.1)
WU2_ERR_T	Normal/Error	Tire air temperature status (wheel unit No.2)
WU3_ERR_T	Normal/Error	Tire air temperature status (wheel unit No.3)
WU4_ERR_T	Normal/Error	Tire air temperature status (wheel unit No.4)
WU1_P	kPa	Tire pressure (wheel unit No.1)
WU2_P	kPa	Tire pressure (wheel unit No.2)
WU3_P	kPa	Tire pressure (wheel unit No.3)
WU4_P	kPa	Tire pressure (wheel unit No.4)
WU1_T	°C, °F	Tire air temperature (wheel unit No.1)
WU2_T	°C, °F	Tire air temperature (wheel unit No.2)
WU3_T	°C, °F	Tire air temperature (wheel unit No.3)
WU4_T	°C, °F	Tire air temperature (wheel unit No.4)
WU1_VPWR	Normal/Error	Supply voltage (wheel unit No.1)
WU2_VPWR	Normal/Error	Supply voltage (wheel unit No.2)
WU3_VPWR	Normal/Error	Supply voltage (wheel unit No.3)
WU4_VPWR	Normal/Error	Supply voltage (wheel unit No.4)

External tester communication function

•  The external tester communication function enables communication of diagnostic data (DTC read-outs, input/output signal read-outs) between the instrument cluster and an external tester.

•  By connecting the Mazda modular diagnostic system (M-MDS) to the DLC-2, diagnostic data can be sent and received between the Mazda modular diagnostic system (M-MDS) and the instrument cluster via CAN lines.

•  The instrument cluster receives the command signals of the malfunction detection function and PID/data monitor function from the Mazda modular diagnostic system (M-MDS), and sends DTCs and data regarding the operating status of each input/output part to the Mazda modular diagnostic system (M-MDS).

Diagnostic function name	Signal received	Signal sent
Malfunction detection function	DTC verification signal	DTC(s)
PID/data monitor function	Command signal to read selected monitor item	Monitored data for requested monitor item