2002 MAZDA 6 engine coolant

TROUBLESHOOTING
F2–207
F2
12 Inspect if turbocharger compressor wheel
locknut is loose or has fallen down inside
turbocharger.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
13 Inspect turbocharger compressor wheel by
hand.
Does wheel turn easily and smoothly?Yes Go to next step.
No Replace turbocharger.
14 Inspect if turbocharger turbine wheel is
damaged, cracked or interfering with housing on
vehicle.
Note
•Inspect all fins on each turbine wheel.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
15 Is any engine oil found inside turbocharger
turbine housing?YesExcessive amount of oil is found:
Replace turbocharger.
Small amount of oil is found:
Wipe oil off of vehicle, then go to next step.
No Go to next step.
16 Is any engine oil found inside turbocharger
compressor hosing?Yes Wipe oil off of vehicle and install all removed parts in
Step 10. Then, go to next step.
No Turbocharger is okay.
Install all parts removed in Step10.
Then, go to next step.
17 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
18 Inspect EGR water cooler for following:
•Coolant passage clogging/restriction
•Exhaust gas clogging/restriction
Is EGR water cooler okay?Yes Go to next step.
No Service as necessary.
19 Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Is glow system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
glow system operation results.
20 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
21 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
22 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•MAP
•RPM
•VSS
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
23 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Replace common rail.
24 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Go to next step.
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION) STEP INSPECTION RESULTS ACTION

F2–210
TROUBLESHOOTING
End Of SieNO.17 COOLING SYSTEM CONCERNS-OVERHEATINGA6E408018881219
Diagnostic Procedure
17
COOLING SYSTEM CONCERNS-OVERHEATING
DESCRIPTION•Engine runs at higher than normal temperature/overheats.
POSSIBLE
CAUSE•Cooling fan No.2 malfunction
•Cooling fan No.1 malfunction
•Low drive belt tension
•Drive belt damage
•Improper coolant level
•Thermostat malfunction
•Radiator clogging
•Improper water/anti-freeze mixture
•Improper or damaged radiator cap
•Radiator hose damage
•Coolant leakage (engine internal, turbocharger, external)
•A/C system malfunction
•EGR system malfunction
•Coolant heater system malfunction
STEP INSPECTION RESULTS ACTION
1 Inspect following:
•Engine coolant level
•Coolant leakage (around heater unit in
passenger compartment, coolant hoses and/
or radiator, and around coolant heater unit.)
•Water and anti-freeze mixture
•Radiator condition
•Collapsed or restricted radiator hoses
•Radiator pressure cap
•Drive belt tension
•Drive belt
•Fan rotational direction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 1.
2 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.

TROUBLESHOOTING
F2–211
F2
End Of Sie
3Note
•The following test should be performed on
the vehicles with A/C system. Go to next
step for vehicles without A/C system
Start engine and run it at idle speed.
Turn A/C switch off.
Does A/C compressor disengaged?Yes Go to next step.
No Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
4 Start engine and run it at idle speed.
Turn A/C switch on if equipped.
Do cooling fan No.1 and/or cooling fan No.2
operate?Yes Go to next step.
NoCooling fan No.1 does not operate:
Inspect for following:
•Cooling fan relay No.1 is stuck open
•Cooling fan motor No.1 malfunction
•Cooling fan motor No.1 GND open
•Open circuit between cooling fan motor No.1 and
relay
•Open circuit between cooling fan relay No.1 and
PCM terminal 102
•Open battery power circuit of cooling fan relay
No.1
Cooling fan No.2 does not operate:
Inspect for following:
•Cooling fan relay No.2 is stuck open
•Cooling fan motor No.2 malfunction
•Cooling fan motor No.2 GND open
•Open circuit between Cooling fan motor No.2 and
relay
•Open circuit between Cooling fan relay No.2 and
PCM terminal 76
•Open battery power circuit of Cooling fan relay
No.2
5 Is drive belt okay? Yes Go to next step.
No Replace drive belt.
6 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
7 Perform coolant heater system inspection.
(See E–10 THERMOSTAT INSPECTION)
Is coolant heater system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
coolant heater system operation results.
8 Cool down engine.
Remove thermostat and inspect operation.
Is thermostat okay?Yes Thermostat is okay.
Inspect cylinder block for leakage or blockage.
No Replace thermostat.
9 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION

F2–212
TROUBLESHOOTING
NO.18 COOLING SYSTEM CONCERNS-RUNS COLDA6E408018881220
Diagnostic Procedure
End Of Sie
18 COOLING SYSTEM CONCERNS-RUNS COLD
DESCRIPTION•Engine takes excessive period for reaching normal operating temperature.
POSSIBLE
CAUSE•Thermostat malfunction
•Cooling fan No.2 system malfunction
•Cooling fan No.1 system malfunction
•Coolant heater system malfunction
STEP INSPECTION RESULTS ACTION
1 Is customer complaint “Lack of passenger
compartment heat”?Yes Inspect A/C heater system.
No Go to next step.
2 Does engine speed continue at fast idle? Yes Go to symptom troubleshooting “NO.7 SLOW
RETURN TO IDLE”.
No Go to next step.
3 Connect WDS or equivalent to DLC-2.
Access ECT PID.
Inspect for both ECT PID and temperature
gauge on instrument cluster readings.
Is ECT PID same as temperature gauge
reading?Yes Go to next step.
No If temperature gauge on instrument cluster indicates
normal range but ECT PID is not same as temperature
gauge reading, inspect ECT sensor.
If temperature gauge on instrument cluster indicates
cold range but ECT PID is normal, inspect
temperature gauge and heat gauge unit.
4 Remove thermostat and inspect operation.
(See E–9 THERMOSTAT REMOVAL/
INSTALLATION)
(See E–10 THERMOSTAT INSPECTION)
Is thermostat okay?Yes Go to next step.
No Replace thermostat.
5 Inspect cooling fan No.1 and cooling fan No.2
operations.
If both or either fan operate normally, inspect for
following:
•Cooling fan relay No.2 is stuck closed
•Short to GND between cooling fan relay No.2
and PCM terminal 76
•Circuit between cooling fan relay No.2 and
fan motor short to battery supply line
•Cooling fan relay No.1 is stuck closed
•Short to GND between cooling fan relay No.1
and PCM terminal 102
•Circuit between cooling fan relay No.1 and
fan motor short to battery supply line
•Short to GND between A/C switch and PCM
terminal 84
Are all circuits okay?Yes Perform coolant heater system inspection.
Repair or replace malfunctioning part according to
coolant heater system operation results.
No Repair or replace as necessary.
6 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION)

K2–12
AUTOMATIC TRANSAXLE
Electronic Control Item and Control
Component Description (Electronic Control)
Control item Contents
Shift control•Detects engine load condition and vehicle speed. Shifts to the best gear
position according to the programmed automatic shift diagram.
Line pressure control•Generates line pressure matching the engine load condition and driving
conditions. Optimizes line pressure for each shift. When the ATF
temperature is low, automatically optimizes line pressure for quick clutch
engagement.
Revers inhibition control•When the shift lever is shifted to R position while the vehicle is running
forward at approx. 30 km/h{19 mph} or more, the TCM turns the neutral
shift solenoid valve on and drains the low and reverse brake hydraulic
pressure. Due to this, the transaxle shifts to neutral.
Shift transient control•Adjusts transient hydraulic pressure according to engine load and
vehicle driving conditions when shifting using the pressure control
solenoid, 2-4 brake solenoid valve, the high clutch solenoid valve, and
each accumulator control valve.
•Temporarily lowers engine torque during shift (up and down) to improve
shift feel
•The lock timing for the reduction brake band is controlled by the control
of the reduction timing solenoid valve ON/OFF timing.
•The lock timing for the clutch brake is controlled by the control of shift
solenoid A, B, and C ON/OFF timing.
Feedback control•Corrects clutch engagement pressure and timing on drain side to
compensate for changes in engine performance and changes in
transaxle
TCC control•Controls TCC according to the programmed TCC points
N-D select control•When a driving range is selected from P/N, the fuel injection amount is
controlled to prevent fluctuation in engine speed.
Slope mode control•Changes the shift point to prevent frequent shifting up/down when
climbing hills
OBD system•Detects and/or memorizes failure of input/output part and transaxle
condition
Part name Function
Input system TR switch•Detects selector lever ranges/positions
Input/turbine speed sensor•Detects reverse clutch drum revolution speed
Intermediate sensor•Detects output gear revolution speed
Vehicle speedometer sensor•Detects parking gear revolution speed
TFT sensor•Detects the ATF temperature
Brake switch•Detects the brake pedal depressed
Cruise control module (in cruise actuator)•When the cruise control is in use, the signal detects when the
difference between the target speed and actual speed
exceeds specification
M range switch•Detects selector lever shifted M range
Up switch•Detects up shift in M range
Down switch•Detects down shift in M range
CAN signal Throttle position signal•Input throttle opening angle from PCM
Engine torque signal
(without torque down)•Input engine torque from PCM
Engine torque signal (with
torque down)•Input engine torque from PCM
Engine torque signal (loss
torque)•Input engine loss torque from PCM
Torque reduced signal•Detects signals indicating torque down availability
Engine coolant
temperature signal•Input engine coolant temperature from PCM
Engine speed signal•Input engine speed from PCM
Battery OFF signal•Detect negative battery cable disconnected
4 wheel speed signal•Input wheel speed from ABS HU/CM or DSC HU/CM

K2–14
AUTOMATIC TRANSAXLE
CAN
signalThrottle
position
signalXX XXXXXX
Engine
torque
signal
(without
torque
down)XXXXXX
Engine
torque
signal
(with
torque
down)XXXXX
Engine
torque
signal
(loss
torque)XXXXXX
Engine
coolant
temperatu
re signalXX
Engine
speed
signalX XXX XX
Torque
reduce
signalXXXXX
Battery
OFF
signalXX
Output
ON/
OFF
typeShift
solenoid
AXX X
Shift
solenoid
BXX X
Shift
solenoid
CXX X
Reduction
timing
solenoid
valveXX X
Neutral
shift
solenoid
valveXXXX X ComponentControl item
Shift
controlLine
pressure
controlReverse
inhibition
controlShift
transient
controlFeedbac
k controlTCC
controlN-D
select
controlSlope
mode
controlOBD
system

K2–50
AUTOMATIC TRANSAXLE
CONTROLLER AREA NETWORK (CAN) DESCRIPTIONA6E571418901201Outline
•The TCM transmits/receives information using the CAN system. See Section T for detailed information
regarding the CAN system.
Structure/Operation
•The PCM inputs throttle opening angle, engine speed, engine torque, engine coolant temperature. to the TCM.
•The TCM operates shift and TCC controls based on the throttle opening angle, and controls line pressure and
other based on the throttle opening angle and the engine torque.
•The TCM outputs reduce torque signal, range signal, turbine speed, ATF temperature signal, and TCC signal to
the PCM.
•If there is an open or short circuit in the CAN wiring, the system determines that the CAN is abnormal and
switches to fail-safe mode.
Input
•Throttle position
•Engine torque (without torque down)
•Engine torque (with torque down)
•Engine torque (loss torque)
•Torque reduction request
•ECT
•Engine speed
•Buttery reconnection
Output
•Range position
•Turbine speed
•ATF temperature
•TCC
•Racing select
•Gear position
•Desired torque
•Desired gear position
•Upper torque limit
•Traveled distance
•MIL indicate request
•AT warning light indicate request
End Of Sie

AUTOMATIC TRANSAXLE
K2–63
K2
Determination of Torque Converter Clutch (TCC) Cancellation
The TCC control is canceled when any of the following condition are met:
•Engine coolant temperature is low.
•ATF temperature is low.
•Brake switch is on (when depressing the brake pedal).
•Accelerator depressing speed and accelerator opening angle are above the set value.
•Engine speed signal is below the set value.
•Failure is in the TCC control system detected by diagnosis function.
End Of Sie
SLOPE MODE CONTROL DESCRIPTIONA6E571418901209•Climbing and the appropriate gear is determined by engine load and the vehicle acceleration.
Slope Mode Control Block Diagram
.
When climbing hill
•When the hill is steeper than a certain grade, unnecessary up shift is prevented by holding an appropriate gear.
End Of Sie
2C 2B
2J
2M1AA 1S 1T 1Z1W 1B 1F
2W
1M 1V2T
2X
PN
RD
M
9
8
7
543
1
2
10
18
17
15
16
14
13
11
12
6
A6E5714W022
1Starter
2 TR switch
3 Down switch
4 Up switch
5 M range switch
6 TFT sensor
7PCM
8CAN
9 Input10 Throttle position signal
Engine speed signal
Engine torque signal
11 TCM
12 Throttle opening angle
13 Shift diagram
14 Vehicle speed
15 VSS
16 Shift solenoid A
17 Shift solenoid B
18 Shift solenoid C