2002 MAZDA 6 engine

ON-BOARD DIAGNOSTIC
K2–143
K2
End Of Sie
5INSPECT LINE PRESSURE
•Start engine.
•Measure line pressure.
Specification
—D range, M (2GR) range
Idle: 290—490 kPa {3.0—4.9 kgf/cm
2, 43—69
psi}
Stall: 1,550—1,750 kPa {15.8—17.8 kgf/cm
2,
225—254 psi}
—M (1GR) range, R position
Idle:550—750 kPa {5.6—7.6 kgf/cm
2, 80—
109 psi}
Stall: 1,550—1,750 kPa {15.8—17.8 kgf/cm
2,
225—254 psi}
•Is line pressure within specification?
(See K2–72 Line Pressure Test.)Yes Go to next step.
No All ranges: Replace or overhaul oil pump or control valve
body, then go to Step 10.
Any ranges: Replace or overhaul automatic transaxle, then
go to Step 10.
(See K2–99 AUTOMATIC TRANSAXLE AND TRANSFER
REMOVAL/INSTALLATION.)
6CLICK TEST OF SOLENOID VALVES
•Turn ignition key to OFF.
•Disconnect terminal component No.1(12-pin).
•Apply battery voltage to terminal component
No.1 (12-pin) terminals (transaxle case side).
—TCC solenoid vale: B
—Pressure control solenoid: D
•Verify the click sounds of TCC solenoid valve
and pressure control solenoid.
•Are there click sounds?Yes Go to next step.
No Replace TCC solenoid valve or pressure control solenoid,
then go to Step 10.
(See K2–105 CONTROL VALVE BODY REMOVAL/
INSTALLATION.)
7INSPECT DIFFERENCE BETWEEN ENGINE
SPEED AND TURBINE SPEED
•Inspect difference between engine speed and
turbine speed during TCC operation in 5GR
•Drive vehicle under following condition
—TR switch position: D range
—Gear position: 5GR
—TCC solenoid valve: ON
•Is difference between engine speed (RPM PID)
and turbine speed okay?
Difference
Below 99 rpmYes Go to Step
No Go to next step.
8INSPECT OPERATION OF EACH VALVE AND
EACH SPRING
•Remove control valve body.
•Disassemble control valve body.
•Is each valve operation okay and is return
spring okay?Yes Replace torque converter, then go to next step.
No Replace control valve body, then go to next step.
(See K2–105 CONTROL VALVE BODY REMOVAL/
INSTALLATION.)
9VERIFY TROUBLESHOOTING OF DTC P0740
COMPLETED
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Start engine.
•Warm up ATX.
•Drive vehicle under following condition for 10
seconds or more.
—Vehicle speed (VSS PID): Within 10—87
km/h {6—54 mph}
—Gear position: 5GR
—TR switch position: D range
—TCC solenoid valve: ON
•Is there pending code present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
10VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION

K2–146
ON-BOARD DIAGNOSTIC
End Of SieDTC P0748A6E577018901214
11INSPECT TERMINAL COMPONENT NO.1 (12-
PIN) CIRCUIT FOR SHORT TO POWER
•Turn ignition key to ON (engine OFF).
•Check voltage at terminal component No.1 (12-
pin) terminal H (harness-side).
•Is voltage 0 V?Yes Go to next step.
No Repair or replace harness, then go to Step 13.
12INSPECT TCM CIRCUIT FOR SHORT TO
GROUND
•Turn ignition key to OFF.
•Check continuity between TCM terminal 2S
(harness-side) and body ground.
•Is there any continuity?Yes Repair or replace harness, then go to next step.
No Go to next step.
13VERIFY TROUBLESHOOTING OF DTC P0743
COMPLETED
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
14VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION
DTC P0748 Pressure control solenoid circuit malfunction (open/short)
DETECTION
CONDITION•Open or short in pressure control solenoid signal system (while TCM monitors solenoid output voltage, the
voltage that differs from the ON/OFF signal output by CPU in TCM is detected).
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL does not illuminate.
•PENDING CODE is not available.
•FREEZE FRAME DATA is not available.
•AT warning light indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Open circuit between pressure control solenoid terminal A and TCM terminal 2Y
•Short to ground between pressure control solenoid terminal A and TCM terminal 2Y
•Short to power between pressure control solenoid terminal A and TCM terminal 2Y
•Pressure control solenoid malfunction
•Damaged connector between pressure control solenoid valve and TCM
•TCM malfunction

K2–148
ON-BOARD DIAGNOSTIC
3INSPECT RESISTANCE
•Check resistance between terminal component
No.1 (12-pin) terminal D (transaxle case side)
and body ground.
•Is resistance within 2.6—3.2 ohms?
(See K2–88 SOLENOID VALVE INSPECTION.)Yes Go to Step 8.
No Go to next step.
4INSPECT COUPLER COMPONENT (10-PIN)
FOR POOR CONNECTION
•Disconnect coupler component (10-pin)
connector.
•Check for poor connection (damaged, pulled-
out, terminals, corrosion, etc.).
•Is terminal okay?Yes Go to next step.
No Repair or replace terminal, then go to Step 12.
5INSPECT RESISTANCE
•Check resistance between coupler component
(10-pin) terminal L (part side) and body ground.
•Is resistance within 2.6—3.2 ohms?
(See K2–88 SOLENOID VALVE INSPECTION.)Yes Repair or replace terminal component No.1 (12-pin), then
go to Step 12.
No Go to next step.
6INSPECT PRESSURE CONTROL SOLENOID
CONNECTOR FOR POOR CONNECTION
•Disconnect pressure control solenoid
connector.
•Check for poor connection (damaged, pulled-
out, terminals, corrosion, etc.).
•Is terminal okay?Yes Go to next step.
No Repair or replace terminal, then go to Step 12.
7INSPECT RESISTANCE
•Check resistance between pressure control
solenoid connector (part side) terminal A and
body ground.
•Is resistance within 2.6—3.2 ohms?
(See K2–88 SOLENOID VALVE INSPECTION.)Yes Repair or replace coupler component (10-pin), then go to
Step 12.
No Verify pressure control solenoid installation.
•If pressure control solenoid is installed correctly,
replace pressure control solenoid, then go to Step 12
(See K2–90 SOLENOID VALVE REMOVAL/
INSTALLATION.)
8INSPECT TCM CONNECTOR FOR POOR
CONNECTION
•Disconnect TCM connector.
•Check for poor connection (damaged, pulled-
out, terminals, corrosion, etc.).
•Are terminals okay?Yes Go to next step.
No Repair terminals, then go to Step 12.
9INSPECT TERMINAL COMPONENT NO.1 (12-
PIN) CIRCUIT FOR OPEN CIRCUIT
•Check continuity between TCM terminal 2Y
(harness-side) and terminal component No.1
(12-pin) terminal D (harness-side).
•Is there continuity between terminals?Yes Go to next step.
No Repair or replace harness, then go to Step 12.
10INSPECT TERMINAL COMPONENT NO.1 (12-
PIN) CIRCUIT FOR SHORT TO POWER
•Turn ignition key to ON (engine OFF).
•Check voltage at terminal component No.1 (12-
pin) terminal D (harness-side).
•Is voltage 0 V?Yes Go to next step.
No Repair or replace harness, then go to Step 12.
11INSPECT TCM CIRCUIT FOR SHORT TO
GROUND
•Turn ignition key to OFF.
•Check continuity between TCM terminal 2Y
(harness-side) and body ground.
•Is there any continuity?Yes Repair or replace harness, then go to next step.
No Go to next step.
12VERIFY TROUBLESHOOTING OF DTC P0748
COMPLETED
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step. STEP INSPECTION ACTION

ON-BOARD DIAGNOSTIC
K2–149
K2
End Of SieDTC P0751A6E577018901215
Diagnostic procedure
End Of Sie
13VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION
DTC P0751 Shift solenoid A malfunction (stuck off)
DETECTION
CONDITION•Difference between actual gear ratio and gear ratio set in TCM is large.
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL illuminates if TCM detects the above malfunction condition.
•PENDING CODE is not available.
•FREEZE FRAME DATA is available.
•AT warning light does not indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Shift solenoid A malfunction
•Shift valve A stuck
•TCM malfunction
STEP INSPECTION ACTION
1VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
•Has FREEZE FRAME PID DATA been
recorded?Yes Go to next step.
No Record FREEZE FRAME PID DATA on repair order, then
go to next step.
2VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Bulletins and/or on-
line repair information availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available repair
information.
•If vehicle is not repaired, go to next step.
No Go to next step.
3CHECK FOR DTC
•Turn ignition key to ON (engine OFF).
•Inspect DTC.
•Is DTC outputted?Yes Follow applicable DTC inspection procedure.
No Go to next step.
4CHECK ATF CONDITION
•Turn ignition key to OFF.
•Check ATF condition.
—Transparent red: Normal
—Milky: Water mixed in fluid
—Reddish brown: Deteriorated ATF
•Is it okay?
(See K2–78 Automatic Transaxle Fluid (ATF)
Condition Inspection.)Yes replace control valve body, then go to next step.
No If ATF color milky or reddish brown, reaper or replace ATX,
then go to next step.
5VERIFY TROUBLESHOOTING OF DTC P0751
COMPLETED.
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Start engine.
•Warm up ATX.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
6VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed.

K2–150
ON-BOARD DIAGNOSTIC
DTC P0752A6E577018901216
Diagnostic procedure
End Of Sie
DTC P0752 Shift solenoid A malfunction (stuck on)
DETECTION
CONDITION•Difference between actual gear ratio and gear ratio set in TCM is large.
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL illuminates if TCM detects the above malfunction.
•PENDING CODE is not available.
•FREEZE FRAME DATA is available.
•AT warning light does not indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Shift solenoid A malfunction
•Shift valve A stuck
•TCM malfunction
STEP INSPECTION ACTION
1VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
•Has FREEZE FRAME PID DATA been
recorded?Yes Go to next step.
No Record FREEZE FRAME PID DATA on repair order, then
go to next step.
2VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Bulletins and/or on-
line repair information availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available repair
information.
•If vehicle is not repaired, go to next step.
No Go to next step.
3CHECK FOR DTC
•Turn ignition key to ON (engine OFF).
•Inspect DTC.
•Is DTC outputted?Yes Follow applicable DTC inspection procedure.
No Go to next step.
4CHECK ATF CONDITION
•Turn ignition key to OFF.
•Check ATF condition.
—Transparent red: Normal
—Milky: Water mixed in fluid
—Reddish brown: Deteriorated ATF
•Is it okay?
(See K2–78 Automatic Transaxle Fluid (ATF)
Condition Inspection.)Yes replace control valve body, then go to next step.
No If ATF color milky or reddish brown, reaper or replace ATX,
then go to next step.
5VERIFY TROUBLESHOOTING OF DTC P0752
COMPLETED.
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Start engine.
•Warm up ATX.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
6VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed.

ON-BOARD DIAGNOSTIC
K2–153
K2
End Of Sie
DTC P0756A6E577018901218
Diagnostic procedure
11INSPECT TERMINAL COMPONENT NO.1 (12-
PIN) CIRCUIT FOR SHORT TO POWER
•Turn ignition key to ON (engine OFF).
•Check voltage at terminal component No.1 (12-
pin) terminal I (harness-side).
•Is voltage 0 V?Yes Go to next step.
No Repair or replace harness, then go to Step 13.
12INSPECT TCM CIRCUIT FOR SHORT TO
GROUND
•Turn ignition key to OFF.
•Check continuity between TCM terminal 2W
(harness-side) and body ground.
•Is there any continuity?Yes Repair or replace harness, then go to next step.
No Go to next step.
13VERIFY TROUBLESHOOTING OF DTC P0753
COMPLETED
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
14VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION
DTC P0756 Shift solenoid B malfunction (stuck off)
DETECTION
CONDITION•Difference between actual gear ratio and gear ratio set in TCM is large.
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL illuminates if TCM detects the above malfunction condition.
•PENDING CODE is not available.
•FREEZE FRAME DATA is available.
•AT warning light does not indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Shift solenoid B malfunction.
•Shift valve B stuck
•TCM malfunction
STEP INSPECTION ACTION
1VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
•Has FREEZE FRAME PID DATA been
recorded?Yes Go to next step.
No Record FREEZE FRAME PID DATA on repair order, then
go to next step.
2VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Bulletins and/or on-
line repair information availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available repair
information.
•If vehicle is not repaired, go to next step.
No Go to next step.
3CHECK FOR DTC
•Turn ignition key to ON (engine OFF).
•Inspect DTC.
•Is DTC outputted?Yes Follow applicable DTC inspection procedure.
No Go to next step.

K2–154
ON-BOARD DIAGNOSTIC
End Of SieDTC P0757A6E577018901219
Diagnostic procedure
4CHECK ATF CONDITION
•Turn ignition key to OFF.
•Check ATF condition.
—Transparent red: Normal
—Milky: Water mixed in fluid
—Reddish brown: Deteriorated ATF
•Is it okay?
(See K2–78 Automatic Transaxle Fluid (ATF)
Condition Inspection.)Yes replace control valve body, then go to next step.
No If ATF color milky or reddish brown, reaper or replace ATX,
then go to next step.
5VERIFY TROUBLESHOOTING OF DTC P0756
COMPLETED.
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Start engine.
•Warm up ATX.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
6VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION
DTC P0757 Shift solenoid B malfunction (stuck on)
DETECTION
CONDITION•Difference between actual gear ratio and gear ratio set in TCM is large.
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL illuminates if TCM detects the above malfunction condition.
•PENDING CODE is not available.
•FREEZE FRAME DATA is available.
•AT warning light does not indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Shift solenoid B malfunction.
•Shift valve B stuck
•TCM malfunction
STEP INSPECTION ACTION
1VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
•Has FREEZE FRAME PID DATA been
recorded?Yes Go to next step.
No Record FREEZE FRAME PID DATA on repair order, then
go to next step.
2VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Bulletins and/or on-
line repair information availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available repair
information.
•If vehicle is not repaired, go to next step.
No Go to next step.
3CHECK FOR DTC
•Turn ignition key to ON (engine OFF).
•Inspect DTC.
•Is DTC outputted?Yes Follow applicable DTC inspection procedure.
No Go to next step.
4CHECK ATF CONDITION
•Turn ignition key to OFF.
•Check ATF condition.
—Transparent red: Normal
—Milky: Water mixed in fluid
—Reddish brown: Deteriorated ATF
•Is it okay?
(See K2–78 Automatic Transaxle Fluid (ATF)
Condition Inspection.)Yes replace control valve body, then go to next step.
No If ATF color milky or reddish brown, reaper or replace ATX,
then go to next step.

ON-BOARD DIAGNOSTIC
K2–155
K2
End Of SieDTC P0758A6E577018901220
5VERIFY TROUBLESHOOTING OF DTC P0757
COMPLETED.
•Make sure to reconnect all disconnected
connectors.
•Clear DTC from memory using WDS or
equivalent.
•Start engine.
•Warm up ATX.
•Drive vehicle in D range and make sure that
gears shift smoothly from 1GR to 5GR.
•Is same DTC present?Yes Replace TCM, then go to next step.
(See K2–96 TCM REMOVAL/INSTALLATION.)
No Go to next step.
6VERIFY AFTER REPAIR PROCEDURE
•Perform “After Repair Procedure”.
(See K2–124 AFTER REPAIR PROCEDURE.)
•Is there any DTC present?Yes Go to applicable DTC inspection.
No Troubleshooting completed. STEP INSPECTION ACTION
DTC P0758 Shift solenoid B circuit malfunction (open/short)
DETECTION
CONDITION•Open or short in shift solenoid B signal system (while TCM monitors solenoid output voltage, the voltage
that differs from the ON/OFF signal output by CPU in TCM is detected).
Diagnostic support note:
•This is a continuous monitor (CCM).
•MIL illuminates if TCM detects the above malfunction conditions during first drive cycle.
•PENDING CODE is not available.
•FREEZE FRAME DATA is available.
•AT warning light indication.
•DTC is stored in TCM memory.
POSSIBLE
CAUSE•Open circuit between shift solenoid B terminal A and TCM terminal 2T
•Short to ground between shift solenoid B terminal A and TCM terminal 2T
•Short to power between shift solenoid B terminal A and TCM terminal 2T
•Shift solenoid B malfunction
•Damage connector between shift solenoid B and TCM
•TCM malfunction