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Mazda 6. Manual - part 212

ON-BOARD DIAGNOSTIC

K–89

DTC P0757

A6E567001030W24

Diagnostic procedure

DTC P0757

Shift solenoid B stuck ON

DETECTION

CONDITION

• When either of DTC P0731 and P0733 are not generated, and both the following conditions are satisfied.

— When all conditions below satisfied while driving in 2GR.

• ATF temperature 20 °C {68 °F} or above.

• Driving in D range.

• Engine run.

• Turbine speed within 225—4,988 rpm.

• Differential gear case (output) revolution speed 35 rpm or above.

• Revolution ratio of forward clutch drum revolution to differential gear case revolution below 1.249 or

more than 2.157.

• Any of the following not generated: DTC P0500, P0705, P0706, P0710, P0715,P0751, P0752,

P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0768, P0771, P0772, P0773.

— When all conditions below satisfied with driving in 4GR.

• ATF temperature 20 °C {68 °F} or above.

• Driving in D range.

• Engine run.

• Turbine speed within 225—4,988 rpm.

• Differential gear case (output) revolution speed 35 rpm or above.

• Vehicle speed 50 km/h {31 mph}.

• Throttle opening angle closed throttle position.

• Revolution ratio of forward clutch drum revolution to differential gear case revolution below 0.6 or

1.249 or above.

• Any of the following not generated: DTC P0500, P0706, P0707, P0708, P0712, P0713, P0715,

P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0767, P0768,
P0771, P0772, P0773.

Diagnostic support note:

• This is a continuous monitor (CCM).

• MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles or in one

drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.

• FREEZE FRAME DATA is available.

• HOLD indicator light flashes.

• DTC is stored in the PCM memory.

POSSIBLE

CAUSE

• ATF level low

• Deteriorated ATF

• Shift solenoid B stuck

• Control valve stuck

• PCM malfunction

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED

• Has FREEZE FRAME PID DATA been

recorded?

Yes Go to next step.

Record FREEZE FRAME PID DATA on repair order, then
go to next step.

VERIFY RELATED REPAIR INFORMATION
AVAILABILITY

• Check for related Service Bulletins 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.

Go to next step.

CHECK ATF CONDITION

• Turn ignition key to OFF.

• Check ATF condition.

— Clear red: Normal
— Milky: Water mixed in fluid
— Reddish brown: Deteriorated ATF

• Is it okay?

(See

K–12 Automatic Transaxle Fluid (ATF)

Condition Inspection

Yes Go to next step.

If ATF color milky or reddish brown, replace ATF, then go to
Step 5.
(See

K–13 AUTOMATIC TRANSAXLE FLUID (ATF)

REPLACEMENT

CHECK ATF LEVEL

• Start engine.

• Warm up ATX.

• Is ATF level within specification?

(See

K–12 Automatic Transaxle Fluid (ATF) Level

Inspection

Yes Go to next step.

Adjust ATF level, then go to Step 7.
(See

K–12 Automatic Transaxle Fluid (ATF) Level

Inspection

K–90

ON-BOARD DIAGNOSTIC

End Of Sie

DTC P0758

A6E567001030W25

INSPECT LINE PRESSURE

• Start engine.

• Measure line pressure.

Specification
Idle: 330—470 kPa {3.4—4.7 kgf/cm

, 49—66

psi}
Stall: 1,200—1,360 kPa {12.3—13.8 kgf/cm

175—196 psi}

• Is line pressure within specification?

(See

K–6 Line Pressure Test

Yes Go to next step.

• All ranges: Replace oil pump or control valve body, then

go to Step 7.

• Any ranges: Replace ATX, then go to Step 7.

(See

K–29 AUTOMATIC TRANSAXLE REMOVAL/

INSTALLATION

(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)

CHECK OPERATION OF EACH VALVE AND
EACH SPRING

• Turn ignition key to OFF.

• Remove control valve body.

• Disassemble control valve body.

• Is each valve operation okay and is return

spring okay?

(See

K–34 CONTROL VALVE BODY REMOVAL

K–35 CONTROL VALVE BODY INSTALLATION

(See ATX Workshop Manual FN4A-EL (9999-95-
FN4A-99).)

Yes Replace ATX, then go to next step.

(See

K–29 AUTOMATIC TRANSAXLE REMOVAL/

INSTALLATION

(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)

Repair or replace shift valve and return spring, then go to
next step.
(See

K–34 CONTROL VALVE BODY REMOVAL

K–35

CONTROL VALVE BODY INSTALLATION

(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)

VERIFY 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 the vehicle under the following conditions

make sure that gears shift smoothly from 1GR
to 4GR.
— ATF temperature: 20

°C {68 °F} or above

— Drive in D range
— Engine speed: 450 rpm or above (RPM

PID)

— Throttle opening angle (TP PID): 0% (4th

gear only)

— Vehicle speed (VSS PID): 50 km/h {31

mph} (4th gear only)

• Is pending code present?

Yes Replace PCM, then go to next step.

(See

F–43 PCM REMOVAL/INSTALLATION

Go to next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See

K–52 AFTER REPAIR PROCEDURE

• Are any DTCs present?

Yes Go to applicable DTC inspection.

Troubleshooting completed.

STEP

INSPECTION

ACTION

DTC P0758

Shift solenoid B malfunction (electrical)

DETECTION

CONDITION

• If PCM detects either of following conditions, PCM determines that shift solenoid B circuit has a

malfunction:
— Shift solenoid B voltage is stuck at B+ after engine start.
— Shift solenoid B voltage is stuck at 0 V after engine start.

Diagnostic support note:

• This is a continuous monitor (CCM).

• MIL illuminates if PCM detects the above malfunction conditions during first drive cycle.

• PENDING CODE is not available.

• FREEZE FRAME DATA is available.

• HOLD indicator light flashes.

• DTC is stored in the PCM memory.

ON-BOARD DIAGNOSTIC

K–91

Diagnostic procedure

POSSIBLE

CAUSE

• Shift solenoid B malfunction

• Short to ground between ATX connector terminal C and PCM terminal 4AC

• Short to power between ATX connector terminal C and PCM terminal 4AC

• Open circuit between shift solenoid B terminal B and ATX connector terminal C

• Open circuit between ATX connector terminal C and PCM terminal 4AC

• Open circuit between shift solenoid B terminal A and body ground point

• Damaged connector between shift solenoid B and PCM

• PCM malfunction

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED

• Has FREEZE FRAME PID DATA been

recorded?

Yes Go to next step.

Record FREEZE FRAME PID DATA on repair order, then
go to next step.

VERIFY RELATED REPAIR INFORMATION
AVAILABILITY

• Check for related Service Bulletins 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.

Go to next step.

INSPECT ATX CONNECTOR FOR POOR
CONNECTION

• Turn ignition key to OFF.

• Disconnect ATX connector.

• Check for poor connection (damaged/pulled-

out terminals, corrosion, etc.).

• Is connection okay?

Yes Go to next step.

Repair or replace connector and/or terminals, then go to
Step 11.

DTC P0758

Shift solenoid B malfunction (electrical)

K–92

ON-BOARD DIAGNOSTIC

End Of Sie

INSPECT RESISTANCE

• Inspect resistance between ATX connector

terminal C (transaxle case side) and body
ground.

• Is resistance within 1.0—4.2 ohms?

(See

K–26 Resistance Inspection (On-Vehicle

Inspection)

Yes Go to Step 7.

Go to next step.

INSPECT SHIFT SOLENOID B CONNECTOR
FOR POOR CONNECTION

• Disconnect shift solenoid B connector.

• Check for poor connection (damaged/pulled-

out terminals, corrosion, etc.).

• Is connection okay?

Yes Go to next step.

Repair or replace connector and/or terminal, then go to
Step 11.

INSPECT RESISTANCE

• Inspect resistance between shift solenoid B

terminals A and B (part-side).

• Is resistance within 1.0—4.2 ohms?

(See

K–27 Resistance Inspection (Off-Vehicle

Inspection)

Yes Replace solenoid harness, then go to Step 11.

Verify shift solenoid B installation.

• If solenoid installed correctly, replace solenoid, then go

to Step 11.

(See

K–28 SOLENOID VALVE REMOVAL/

INSTALLATION

INSPECT PCM CONNECTOR FOR POOR
CONNECTION

• Disconnect PCM connector.

• Check for poor connection (damaged/pulled-

out terminals, corrosion, etc.).

• Is connection okay?

Yes Go to next step.

Repair or replace connector and/or terminals, then go to
Step 11.

INSPECT ATX CONNECTOR CIRCUIT FOR
OPEN

• Inspect for continuity between PCM terminal

4AC (harness-side) and ATX connector
terminal C (vehicle harness-side).

• Is there continuity between terminals?

Yes Go to next step.

Repair or replace harness, then go to Step 11.

INSPECT ATX CONNECTOR CIRCUIT FOR
SHORT TO POWER

• Turn ignition key to ON (engine OFF).

• Check for voltage at ATX connector terminal C

(vehicle harness-side).

• Is voltage 0 V?

Yes Go to next step.

Repair or replace harness, then go to Step 11.

INSPECT PCM CIRCUIT FOR SHORT TO
GROUND

• Turn ignition key to OFF.

• Check for continuity between PCM terminal

4AC (harness-side) and body ground.

• Is there continuity?

Yes Repair or replace harness, then go to Step 11.

Go to next step.

VERIFY TROUBLESHOOTING OF DTC P0758
SHIFT SOLENOID B 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 4GR.

• Are any DTCs present?

Yes Replace PCM, then go to next step.

(See

F–43 PCM REMOVAL/INSTALLATION

Go to next step.

VERIFY AFTER REPAIR PROCEDURE

• Perform “After Repair Procedure”.

(See

K–52 AFTER REPAIR PROCEDURE

• Are any DTCs present?

Yes Go to applicable DTC inspection.

Troubleshooting completed.

STEP

INSPECTION

ACTION

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