ON-BOARD DIAGNOSTIC FUNCTION

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Malfunction detection function

•  Detects errors in the input and output signals. (Switch the ignition to ON position or the engine is running.)
•  If a malfunction is detected, a DTC is output to the DLC-2 through the malfunction display function. At the same time, malfunction detection results are sent to the fail-safe and memory functions.

Fail-safe function

•  If a malfunction is detected by the malfunction detection function and a malfunction is determined, the following controls are performed to prevent an operating malfunction of the full-auto air conditioner and malfunction of output parts.

Fail-safe Function Table

Part where malfunction is determined

Malfunction determined when IG SW at ON

Malfunction already exists when IG SW turned to ON
Cabin temperature sensor
Cabin temperature sensor input value is fixed at the value right before the malfunction.
Cabin temperature sensor input value is fixed at 25 °C {77 °F}.
Evaporator temperature sensor
Evaporator temperature sensor input value is fixed at 0 °C {32 °F}.
←
Solar radiation sensor
Solar radiation sensor value is fixed at the value right before the malfunction.
Solar radiation sensor value is fixed at 0 W/m2.
Air mix actuator
(potentiometer)
Air mix actuator drive signal is stopped right when the malfunction is determined.
However, it is fixed at MAX COLD when the manually set temperature is at 15 and fixed at MAX HOT when the manually set temperature is at 29.
Control based on ambient temperature. (See Graph 1.)
However, it is fixed at MAX COLD when the manually set temperature is at 15 and fixed at MAX HOT when the manually set temperature is at 29.
Airflow mode actuator
(potentiometer)
Airflow mode actuator drive signal is stopped right when the malfunction is determined.
•  However, change the operation to VENT or DEF when the manual operation selected to VENT or DEF.
Control based on ambient temperature. (See Graph 2.)
•  However, change the operation to VENT or DEF when the manual operation selected to VENT or DEF.
Air mix actuator
(motor lock)
Air mix actuator drive signal is stopped right when the malfunction is determined.
Air mix actuator drive signal is output normally. After this, a drive signal is stopped when the malfunction is determined.
Airflow mode actuator
(motor lock)
Airflow mode actuator drive signal is stopped right when the malfunction is determined.
Airflow mode actuator drive signal is output normally. After this, a drive signal is stopped when the malfunction is determined.

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Sensor Signal Delay Function

•  Due to factors such as direct and intermittent sunlight (travelling through a city or highway tunnel), or radiant heat from the ground under a parked vehicle as well as the opening and closing of doors, the amount of solar radiation, and the ambient and cabin temperatures may change intermittently, partially, or suddenly. If control was performed based exactly on these variations, the air conditioning function would be negatively effected and smooth control could not occur. In order to prevent this, the climate control unit delays the input signals for solar radiation, and the ambient and cabin temperature as shown in the following figure. Stable control occurs due to the reading out of an average of all the variations.
•  When the engine is re-started after being temporarily stopped, the ambient temperature sensor may detect a temperature higher then the actual ambient temperature. To prevent this, when the engine coolant temperature exceeds the specified value, the detected ambient temperature is corrected based on the data for the ambient temperature before the engine was stopped that is stored in climate control unit and control is performed accordingly.
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Memory Function

•  Stores the signal determined to be malfunctioning by the malfunction detection function, and the memory is not cleared even if the ignition is switched to off or the malfunction has been repaired.
•  Clear stored malfunction data by connecting the Mazda Modular Diagnostic System (M-MDS) to the DLC-2.

Display Function

•  This function is for outputting present or past malfunctions via the DLC-2 as DTCs.
•  DTCs output via the DLC-2 can be read out using the Mazda Modular Diagnostic System (M-MDS).
Malfunction Display Mode
•  Present and past malfunctions in the control system circuits (open/short circuits) are detected, and the DTCs indicated in the table are displayed on the Mazda Modular Diagnostic System (M-MDS). Since once a past malfunction is stored, it will remain stored even after the malfunction has been repaired, clear past malfunctions after completing repairs.
•  Clear stored past malfunctions by connecting the Mazda Modular Diagnostic System (M-MDS) to the DLC-2.

DTC table (climate control system)

DTC

Malfunction location

Detected condition

Memory function
B1081:71
Left side air mix actuator
Stuck
X
B1082:71
Right side air mix actuator
Stuck
X
B1086:71
Airflow mode actuator
Stuck
X
B1A61:11
Cabin temperature sensor
Circuit short to ground
X
B1A61:13
Circuit open
X
B1A63:12
Solar radiation sensor (RH)
Circuit shot to power supply
—
B1A63:13
Circuit open
—
B1A64:12
Solar radiation sensor (LH)
Circuit shot to power supply
—
B1A64:13
Circuit open
—
B1B71:11
Evaporator temperature sensor
Circuit short to ground
X
B1B71:13
Circuit open
X
B1C1A:11
Left side air mix actuator (potentiometer)
Circuit short to ground
X
B1C1A:13
Circuit open
X
B1C1B:11
Right side air mix actuator (potentiometer)
Circuit short to ground
X
B1C1B:13
Circuit open
X
B1C1C:11
Airflow mode actuator (potentiometer)
Circuit short to ground
X
B1C1C:13
Circuit open
X
U0010:88
CAN communication system
Bus off
X
U0155:00
Lost communication with Instrument cluster
No sub type information
X
U0184:00
Lost communication with audio unit/car-navigation unit
No sub type information
—
U0423:68
Invalid data received from instrument cluster
Event information
X

DTC table (water heater system)

DTC

Malfunction location

Detected condition

Memory function
B1D24:11
Glow plug
Circuit short to ground
X
B1D24:15
Circuit short to power supply or open
X
B1D25:11
Fuel pump (water heater system)
Circuit short to ground
X
B1D25:15
Circuit short to power supply or open
X
B1D26:11
Blower fan
Circuit short to ground
X
B1D26:15
Circuit short to power supply or open
X
B1D29:93
No start, even after restart attempt
No operation
X
B1D30:93
No start in test mode
No operation
X
B1D31:94
Flame detected prior to normal operation
Unexpected operation
X
B1D32:92
Multiple flame interruption during heating cycle
Performance or incorrect operation
X
B1D34:68
Heater in lock out mode
Event information
X
U0001:88
HS-CAN communication bus
Bus off
X
U0100:00
Lost communication with PCM
No sub type information
X
U0140:00
Lost communication with BCM
No sub type information
X
U0155:00
Lost communication with instrument cluster
No sub type information
X
U3000:49
Control module
Internal electronic failure
X
U3003:16
Power supply circuit (battery voltage)
Circuit voltage below threshold
X
U3003:17
Circuit voltage above threshold
X


PID/data Monitor Function

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

PID/data monitor table (climate control system)

PID name (definition)

Input part

Unit/Condition
CABIN_TEMP
Cabin temperature sensor
°C
EVAP_TEMP
Evaporator temperature sensor
°C
SOLAR_SSR_L
Solar radiation sensor (LH)
W
SOLAR_SSR_R
Solar radiation sensor (RH)
W

PID/data monitor table (water heater system)

PID name (definition)

Input signal

Unit/Condition
ECT
Engine coolant temperature
°C
EX_TEMP
Ambient temperature
°C
GLOW_PLUG
Glow plug duty cycle
%
HEATER_FAN
Heater fan
V
PRIM_TIME
Priming time
s
RPM
Engine revolutions per minute
RPM
START_CNT
Start counter
-
VOLT_LOW
Low voltage threshold
V
VOLT_OP
Operating voltage
V
VPWR
Module supply voltage
V
WATER_TEMP
Water temperature
°C


Active Command Modes Function

•  The simulation function is used for optionally selecting simulation items of output parts preset in the climate control unit, and to operate them regardless of the climate control unit control.

Active command modes table

Command name

Output part

Operation

Operating condition
BLOWER
Blower motor
On/Off
Ignition is switched to ON
DISPLAY
Information display
MODE_ACT
Airflow mode actuator
MIX_ACT
Air mix actuator
REC/FRESH
REC/FRESH switch


A/C Operation Check Mode

•  The climate control unit forces operation of output related moving parts as indicated in the operation check table regardless of input related parts, while simultaneously changing the display on the information display as well as illuminating each switch indicator light automatically. A malfunctioning part can be determined by verifying that each transition is as indicated in the operation check table through visual inspection, listening to the operation sound, or placing a hand on the air vent.

Mazda Modular Diagnostic System (M-MDS) display

Target part

Operation condition
Illumination of All Indicator Lights
Climate control unit
All A/C indicator lights illuminated
Blower Motor Speed
Blower motor
Air Mix Actuator
Air mix door
Air Flow Mode Actuator
Airflow mode door
Air Intake Actuator / Air Conditioning Compressor
Air intake door
A/C compressor
FRESH Û REC
ON Û OFF

*  :Shown on the information display (at the set temperature display) according to each Mazda Modular Diagnostic System (M-MDS) display.