2002 MAZDA 6 ignition

K2–192
TROUBLESHOOTING
NO.8 DOES NOT SHIFT TO FIFTH GEAR (5GR)A6E578001030211
Diagnostic procedure
8 Does not shift to fifth gear (5GR)
DESCRIPTION•Vehicle does not upshift from 4GR to 5GR even though vehicle speed increased.
•Vehicle does not shift to 5GR even though accelerator pedal released in D range at 60 km/h {37 mph}.
POSSIBLE
CAUSE•Basically, TCC does not operate when fail-safe is operating. Verify DTC at first. If TCC operates when
driving at high speeds only, malfunction (improper adjustment) is in the D range switch circuit or TR
switch circuit.
Note
•If the TCC or piston is stuck, inspect them. In addition, inspect the oil cooler for foreign particles
which may have mixed in with the ATF.
—TCC piston slipped, burned
•Line pressure low
•Incorrect throttle position signal
•Malfunction of ECT sensor
•Malfunction of VSS
•Malfunction of input/turbine speed sensor
•Malfunction of sensor ground
—Malfunction of TFT sensor
•Short or open circuit in wiring
•Poor connection of connector
•Malfunction of sensor
—Malfunction of TR switch
•Selector lever adjustment incorrect
•TR switch adjustment incorrect
—Malfunction of TCC solenoid valve
•Short or open circuit in wiring
•Poor connection of connector
•Solenoid valve stuck
—Malfunction of M range switch
—Malfunction of torque converter
—Malfunction of control valve body
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
STEP INSPECTION ACTION
1•Turn ignition switch to ON.
•Does gear position indicator light indication
correspond to selector lever position?Yes Go to next step.
No Go to symptom troubleshooting No.27 “Gear position
indicator light does not illuminate in M range” or No.28
“Gear position indicator light illuminates in D range or P, N,
R positions”.
2•Drive vehicle in D range and inspect
following:
—1–2 shift up and down
—2–3 shift up and down
—3–4 shift up and down
—4–5 shift up and down
•Are all shift-up and shift-down possible?Yes Go to next step.
NoNo shift at all:
•Go to symptom troubleshooting No.7 “No shifting”.
Abnormal shift:
•Go to symptom troubleshooting No.9 “Abnormal
shifting”.
3•Stop engine.
•Inspect shift solenoid A, B, or C circuit.
•Are they okay?Yes Go to next step.
No•Inspect for shift solenoid mechanical stuck.
(See K2–88 SOLENOID VALVE INSPECTION.)
4•Remove torque converter.
•Inspect torque converter.
(See ATX Workshop.)
•Is torque converter okay?Yes•Overhaul control valve body and repair or replace any
defective parts.
(See ATX Workshop Manual.)
—If problem remains, replace or overhaul transaxle and
repair or replace any defective parts.
(See K2–99 AUTOMATIC TRANSAXLE AND
TRANSFER REMOVAL/INSTALLATION.)
(See ATX Workshop Manual.)
No Replace torque converter.

K2–194
TROUBLESHOOTING
NO.11 SHIFT POINT IS HIGH OR LOWA6E578001030214
End Of SieNO.12 TORQUE CONVERTER CLUTCH (TCC) NON-OPERATIONA6E578001030215
Diagnostic procedure
11 Shift point is high or low
DESCRIPTION•Shift point considerably different from automatic shift diagram.
•Shift delays when accelerating.
•Shift occurs quickly when accelerating and engine speed does not increase.
POSSIBLE
CAUSE•If the transaxle does not shift abnormally, there is a malfunction of input signal to TP sensor, input/
turbine speed sensor, or VSS.
•If engine speed is high or low regardless that shifting is normal, inspect tachometer.
•Verify that output signal of TP sensor changes linearly.
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
12 Torque converter clutch (TCC) non-operation
DESCRIPTION•TCC does not operate when vehicle reaches TCC operation range.
POSSIBLE
CAUSE•Basically, TCC does not operate when fail-safe is operating. Verify DTC at first. If TCC operates when
driving at high speeds only, the malfunction (improper adjustment) is in D and/or M ranges switch circuit
or TR switch circuit.
Note
•If the TCC or piston is stuck, inspect them. In addition, inspect the oil cooler for foreign particles
which may have mixed in with the ATF.
•TCC piston slipped, burned
—Line pressure low
•Incorrect throttle position signal
•Input/turbine speed sensor malfunction
•TFT sensor malfunction
•Sensor ground malfunction
•VSS malfunction
•Malfunction of output solenoid valve system (Sticking)
•TCC solenoid valve malfunction
•Malfunction of control valve body system (Poor operation, sticking)
•TCC piston hydraulic pressure system malfunction
•Malfunction of TP sensor (Not operating linearly)
•Malfunction of input/turbine speed sensor or VSS
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
STEP INSPECTION ACTION
1•Turn ignition switch to ON.
•Does gear position lamp indication
correspond to selector lever position?Yes Go to next step.
No Go to symptom troubleshooting No.27 “Gear position
indicator light does not illuminate in M range”, or No.28
“Gear position indicator light illuminates in D range or P, N,
R positions”.
2•Disconnect TCM.
•Is resistance between ground terminals 1C,
1Y at TCM connector and body ground less
than 5.0 ohm?Yes Go to next step.
No Repair open ground circuit.
3•Remove torque converter.
•Inspect torque converter.
(See ATX Workshop Manual.)
•Is torque converter okay?Yes•Overhaul control valve body and repair or replace any
defective parts.
(See ATX Workshop Manual.)
•If problem remains, replace or overhaul transaxle and
repair or replace any defective parts.
(See ATX Workshop Manual.)
No•Replace torque converter.
4•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM.

TROUBLESHOOTING
K2–197
K2
End Of SieNO.18 EXCESSIVE SHIFT SHOCK IS GIVEN WHEN UPSHIFTING AND DOWNSHIFTINGA6E578001030221
End Of SieNO.19 EXCESSIVE SHIFT SHOCK ON TORQUE CONVERTER CLUTCH (TCC)A6E578001030222
End Of Sie
3•Is line pressure okay?
(See K2–72 Line Pressure Test.)Yes Go to next step.
No Repair or replace any defective parts according to
inspection results.
4•Is stall speed okay?
(See K2–74 Stall Speed Test.)Yes Go to next step.
No Go to Step 6.
5•Inspect TR switch and related harness:
vibration, intermittent open/short circuit.
•Is it okay?Yes Go to next step.
No Repair or replace part if necessary.
6•Stop engine and turn ignition switch on.
•Inspect pressure control solenoid circuit.
•Is it okay?Yes•Overhaul control valve body and repair or replace any
defective parts.
(See ATX Workshop Manual.)
•If problem remains, replace or overhaul transaxle and
repair or replace any defective parts.
(See ATX Workshop Manual.)
No•Inspect for pressure control solenoid mechanical stuck.
(See K2–88 SOLENOID VALVE INSPECTION.)
7•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM. STEP INSPECTION ACTION
18 Excessive shift shock is given when upshifting and downshifting
DESCRIPTION•Excessive shift shock felt when depressing accelerator pedal to accelerate at upshifting.
•During cruising, excessive shift shock felt when depressing accelerator pedal at downshifting.
POSSIBLE
CAUSE•Shift shock may worsen when fail-safe is operating. The shift shock has worsen if TP sensor, input/
turbine speed sensor, or VSS signal malfunctions.
—Clutch slipped, burned
•Line pressure low, high
•Incorrect throttle position signal
•Malfunction of VSS
•Malfunction of input/turbine speed sensor
•Malfunction of TFT sensor
•Malfunction of shift solenoid A, B, or C
•Malfunction of TCC solenoid valve
•Misadjustment of throttle cable
•Malfunction of body ground and sensor ground
•Malfunction of control valve body
—Poor hydraulic operation (Malfunction in range change)
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
19 Excessive shift shock on torque converter clutch (TCC)
DESCRIPTION•Strong shock felt when TCC engaged.
POSSIBLE
CAUSE•The troubleshooting flow is the same as No.16 “Judder upon torque converter clutch (TCC) operation”.
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.

K2–200
TROUBLESHOOTING
Diagnostic procedure
End Of SieNO.25 ENGINE STALLS WHEN DRIVING AT SLOW SPEED OR STOPPINGA6E578001030228
Diagnostic procedure
End Of SieNO.26 STARTER DOES NOT WORKA6E578001030229
End Of SieNO.27 GEAR POSITION INDICATOR LIGHT DOES NOT ILLUMINATE IN M RANGEA6E578001030230
Diagnostic procedure
STEP INSPECTION ACTION
1•Go to symptom troubleshooting No.4
“Engine stalls-after start/at idle”.
(See Section F.)
•Is engine control system okay?Yes Go to next step.
No Repair or replace any defective parts according to
inspection results.
2•Remove torque converter.
•Inspect torque converter.
(See ATX Workshop Manual.)
•Is torque converter okay?Yes•Inspect for bend, damage or kinks of oil cooler line
pipes. If okay, overhaul control valve body and repair or
replace any defective parts.
(See ATX Workshop Manual.)
•If problem remains, replace or overhaul transaxle and
repair or replace any defective parts.
(See ATX Workshop Manual.)
No Replace torque converter.
3•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM.
25 Engine stalls when driving at slow speeds or stopping
DESCRIPTION•Engine stalls when brake pedal depressed while driving at low speed or stopping.
POSSIBLE
CAUSE•Malfunction is on engine control side (e.g. Fuel injection control, IAC system)
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
STEP INSPECTION ACTION
1•Go to symptom troubleshooting No.10 “Low
idle/stalls during deceleration”.
(See Section F.)
•Is engine control system okay?Yes Go to symptom troubleshooting No.24 “Engine stalls when
shifted to D range, or in R position”.
No Repair or replace any defective parts according to
inspection results.
2•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM.
26Starter does not work
DESCRIPTION•Starter does not work even when P or N position.
POSSIBLE
CAUSE•Selector lever misadjustment.
•TR switch misadjustment.
•Open or short circuit in TR switch.
27 Gear position indicator light does not illuminate in M range
DESCRIPTION•Gear position indicator light in instrument cluster does not illuminate in M range and ignition switch at
on.
POSSIBLE
CAUSE•M range switch, gear position indicator light or related wiring harness malfunction.
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
STEP INSPECTION ACTION
1•Are other indicator lights illuminated with
ignition switch on? Yes Go to next step.
No Inspect meter fuse.

TROUBLESHOOTING
K2–201
K2
End Of SieNO.28 GEAR POSITION INDICATOR LIGHT ILLUMINATES IN D RANGE OR IN P, N, R POSITIONSA6E578001030231
Diagnostic procedure
End Of SieNO.29 DOES NOT SHIFT UP IN M RANGEA6E578001030232
End Of SieNO.30 DOES NOT SHIFT DOWN IN M RANGEA6E578001030233
End Of Sie
2•Inspect MNL SW PID value using WDS or
equivalent.
•Are these PIDs okay?Yes Inspect instrument cluster.
No Inspect M range switch.
If M range switch is okay, inspect for continuity between M
range switch and TCM terminal 1AA.
3•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM. STEP INSPECTION ACTION
28 Gear position indicator light illuminates when D range or P, N, R positions
DESCRIPTION•Gear position indicator light in instrument cluster illuminates in D range or P, N, R positions and ignition
switch at on.
POSSIBLE
CAUSE•M range switch or related wiring harness malfunction.
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board Diagnostic
and Automatic Transaxle Basic Inspection are conducted.
STEP INSPECTION ACTION
1•Inspect MNL SW PID value using WDS or
equivalent.
•Are these PIDs okay?Yes Inspect instrument cluster.
No Inspect M range switch.
If M range switch is okay, inspect for continuity between M
range switch and TCM terminal 1AA.
2•Verify test results.
—If okay, return to diagnostic index to service any additional symptoms.
—If malfunction remains, inspect related Service Informations and perform repair or diagnosis.
—If vehicle repaired, troubleshooting completed.
—If vehicle not repaired or additional diagnostic information not available, replace TCM.
29Does not shift up in M range
DESCRIPTION•Gear position indicator light in instrument cluster illuminates, but vehicle does not upshift when selector
lever is pushed to “+” side.
POSSIBLE
CAUSE•Up switch or related harness malfunction
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board
Diagnostic and Automatic Transaxle Basic Inspection are conducted.
30 Does not shift up in M range
DESCRIPTION•Gear position indicator light in instrument cluster illuminates, but vehicle does not downshift when
selector is pushed lever to “–” side.
POSSIBLE
CAUSE•Down switch or related harness malfunction
Note
•Before following troubleshooting steps, make sure that Automatic Transaxle On-Board
Diagnostic and Automatic Transaxle Basic Inspection are conducted.

M–8
ELECTRONIC 4WD CONTROL SYSTEM
Components and Functions
System Diagram
.
Part name Function
Electronic control coupling
(4WD solenoid)•Based on a signal from the 4WD CM, it operates the electromagnetic clutch and
transmits drive torque to the rear wheels.
Differential oil temperature
sensor•Informs the 4WD CM of the rear differential oil temperature.
4WD CM•Controls operation of the electronic control coupling (4WD solenoid) based on signals
input from the throttle opening angle, speed, differential oil temperature and other
sensors.
•Outputs coupling control condition and 4WD warning control information as a CAN
signal.
•Controls the on-board diagnostic system and the fail-safe system if there is a malfunction
in the 4WD system.
4WD warning light•Illuminates or flashes to alert driver of a malfunction or control failure in the 4WD system.
PCM•Sends the throttle opening angle and engine speed signals, as CAN signals, to the 4WD
CM.
TCM•Sends the selector lever position and gear position signals, as CAN signals, to the 4WD
CM.
DSC HU/CM•Sends the four-wheel speed and DSC operating condition signals, as CAN signals, to the
4WD CM.
•Sends the coupling torque request signal, as a CAN signal, to the 4WD CM.
KO
P I
A
C
NH G
9
8
7
5
4
3
10
13
11
12
6
1
2
A6E63222002
1 Battery
2 Ignition switch
3 Differential oil temperature sensor
4 4WD control modure (4WD CM)
5 Electronic control coupling
6 4WD solenoid
7 Instrument cluster8 DSC HU/CM
9TCM
10 PCM
11 CAN-H
12 CAN-L
13 CAN driver

M–16
ELECTRONIC 4WD CONTROL SYSTEM
ON-BOARD DIAGNOSTICA6E632227100208Outline
•The on-board diagnostic function allows for detecting malfunctions in the input/output signals when the ignition
key is at the ON position.
•The DLC-2, which combines the failure detection and detection maintenance connectors, has been adopted to
improve serviceability. By connecting a WDS or equivalent to the DLC-2, malfunction diagnosis can be carried
out.
•Using a WDS or equivalent DTCs can be retrieved or erased, depending on the screen display, thus improving
serviceability.
Block diagram
.
Self-diagnostic function
Failure detection function
•The failure detection function detects malfunctions in the input/output signal systems of the 4WD CM and
displays them when the ignition key is at the ON position.
•When the ignition key is turned to the ON position, the 4WD CM system begins operation, and the 4WD
warning light illuminates for 3 seconds while the function checks for open circuits. At the same time the function
monitors the condition of the power supply voltage and checks for internal malfunctions.
•Then, once the system is running, the function checks the operating conditions of the 4WD solenoid and the
differential oil temperature sensor at regular intervals to determine whether there is any malfunction.
•If any malfunction is detected during these diagnostic tests, the warning light illuminates according to the
malfunction to alert the driver. Also, a DTC is output to DLC-2 via the CAN line. Also, at the same time the
failure detection result is sent to the memory and fail-safe functions.
9
87
5
4
3
10
13
11
12
6
12
A6E63222010
1 Input part
2 Regular control area
3 Output part
4 Fail-safe function
5 Failure detection function
6 Memory function
7 Failure display function8 External tester communication function
9 Failure diagnosis function
10 4WD warning light
11 DLC-2
12 CAN
13 WDS or equivalent

ELECTRONIC 4WD CONTROL SYSTEM
M–17
M
Memory function
•This function stores DTCs for malfunctions of the input/output signal systems as determined by the failure
detection function. Once a DTC is stored, it is not cleared even if the input/output signal system malfunction
returns to normal when the ignition key is turned to the LOCK position (engine OFF).
•Since DTCs are stored in the non-volatile memory inside the 4WD CM, they are not cleared even if the battery
is disconnected. Therefore, it is necessary to clear the memory when maintenance has been completed. For
clearing DTCs, refer to the procedures in the Workshop Manual.
•When inspecting DTCs using a WDS or equivalent, only one memory stored DTC at a time can be displayed.
Therefore, when multiple DTCs have been stored, it is necessary to inspect for DTCs again after repairing and
clearing the present DTC to ensure that there are no more DTCs present in the memory.
Fail-safe function
•When the failure detection function determines that there is a malfunction, the 4WD warning light illuminates to
alert the driver. At this time, the fail-safe function suspends control or takes other measures to ensure that
driving stability is not lost.
X:Available
*1: Does not illuminate when only the coupling torque request signal from the DSC HU/CM cannot be received.*2: Only integrated DSC control is prohibited when only the coupling torque request signal from the DSC HU/CM
cannot be received.
External tester communication function
•This function allows for the storing and clearing of DTCs due to a communication link between the 4WD CM
and an external tester.
End Of Sie
DTC Malfunction location4WD warning
lightconditionDTC stored in
memoryControl condition
P1887 System wiring Illuminated X Stop
P1888 Differential oil temperature sensor Illuminated X Stop
U0100 PCM communication system Illuminated X Stop
U0101 TCM communication system Illuminated X Stop
U0121 DSC communication system
Illuminated
*1X
Stop*2