Mazda DTC P0731 Diagnostic

DTC P0731	Gear 1 incorrect (incorrect gear ratio detected)
DETECTION CONDITION	• The PCM monitors the revolution ratio of the forward clutch drum revolution to differential gear case revolution when the following monitoring conditions are met. If the revolution ratio is below 2.16, the PCM determines that there is a malfunction. Monitoring condition: – ATF temperature 20 °C {68 °F} or more – Driving in 1GR in D or M range – Engine running – Turbine speed within 225-4,987 rpm – Throttle opening angle 2.66% or more – Differential gear case (output) revolution speed 35 rpm or more. – None of the following present: DTC P0500, P0706, P0707, P0708, P0712, P0713, P0715, P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0768, P0771, P0772, P0773 Diagnostic support note: • This is a continuous monitor (CCM). • The MIL does not illuminate. • The AT warning light illuminates if the PCM detects the above malfunction condition during the first drive cycle. • FREEZE FRAME DATA is not available. • A PENDING CODE is not available. • The DTC is stored in the PCM memory.
POSSIBLE CAUSE	• ATF level low • Deteriorated ATF • Shift solenoid A stuck • Pressure control solenoid stuck • Line pressure low • One-way clutch slipping • Forward clutch slipping • Control valve stuck • Oil pump malfunction • PCM malfunction

DTC P0731

Gear 1 incorrect (incorrect gear ratio detected)

DETECTION CONDITION

• The PCM monitors the revolution ratio of the forward clutch drum revolution to differential gear case revolution when the following monitoring conditions are met. If the revolution ratio is below 2.16, the PCM determines that there is a malfunction.

Monitoring condition:

– ATF temperature 20 °C {68 °F} or more

– Driving in 1GR in D or M range

– Engine running

– Turbine speed within 225-4,987 rpm

– Throttle opening angle 2.66% or more

– Differential gear case (output) revolution speed 35 rpm or more.

– None of the following present: DTC P0500, P0706, P0707, P0708, P0712, P0713, P0715, P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0766, P0767, P0768, P0771, P0772, P0773

Diagnostic support note:

• This is a continuous monitor (CCM).

• The MIL does not illuminate.

• The AT warning light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA is not available.

• A PENDING CODE is not available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• ATF level low

• Deteriorated ATF

• Shift solenoid A stuck

• Pressure control solenoid stuck

• Line pressure low

• One-way clutch slipping

• Forward clutch slipping

• Control valve stuck

• Oil pump malfunction

• PCM malfunction

Diagnostic procedure


STEP	INSPECTION		ACTION
1	VERIFY RELATED REPAIR INFORMATION AVAILABILITY • Verify related Service Bulletins and/or on-line repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information.
1		No	Go to the next step.
2	INSPECT ATF CONDITION • Inspect the ATF condition. • Is it normal?	Yes	Go to the next step.
2		No	Replace the transaxle, then go to Step 8.
3	INSPECT ATF LEVEL • Start the engine. • Warm up the ATX. • Is the ATF level within the specification?	Yes	Go to the next step.
3		No	Add ATF to the specified level, then go to Step 8.
4	INSPECT SHIFT SOLENOID VALVE A • Perform operation inspection. • Verify the click sound of shift solenoid A when applying B+ to transaxle terminal A. • Was a click heard from solenoids?	Yes	Go to the next step.
4		No	Replace the solenoid that you could not hear a click sound, then go to Step 8.
5	INSPECT LINE PRESSURE • Start the engine. • Measure the line pressures. Specification Idle: 330-470 kPa {3.4-4.7 kgf/cm², 48-68 psi} Stall: 1,090-1,250 kPa {11.2-12.7 kgf/cm², 159-181 psi} (Z6) 1,160-1,320 kPa {11.8-13.5 kgf/cm², 168-191 psi} (LF) • Are the line pressures within the specifications?	Yes	Go to the next step.
5		No	All ranges: Replace the oil pump, then go to Step 8. Any ranges: Replace the control valve body, then go to Step 8.
6	INSPECT STALL SPEED • Measure the stall speed in D range. Specification 2,100-2,700 rpm (Z6) 2,000-2,600 rpm (LF) • Is the stall speed within the specification?	Yes	Go to the next step.
6		No	Replace the automatic transaxle, then go to Step 8.
7	INSPECT FREQUENCY OF INPUT/TURBINE SPEED SENSOR WHEN DRIVING VEHICLE • Turn the ignition switch to the LOCK position. • Connect the WDS or equivalent. • Start the engine. • Measure the frequency of input/turbine speed sensor while driving vehicle under the following conditions: – Vehicle speed (VSS PID): 20 km/h {12 mph} – Drive in the D range, 1GR – Throttle opening angle (TP PID): approx. 25% • Was the frequency of the input/turbine speed sensor at approx. 1,100 Hz?	Yes	Go to the next step.
7		No	Replace the control valve body, then go to the next step.
8	VERIFY REPAIR OF DTC P0731 • Make sure to reconnect all the disconnected connectors. • Clear the DTC using the WDS or equivalent. • Start the engine. • Warm up the transaxle. • Drive the vehicle under the following conditions at least 4 times for more than 1 s: – ATF temperature: 20 °C {68 °F} or more – Drive in the D range, 1GR – Throttle opening angle (TP PID): 5.67% or more – Vehicle speed (VSS PID): 4 km/h {3 mph} or more • Are any DTCs present?	Yes	Replace the PCM, then go to the next step.
8		No	Go to the next step.
9	VERIFY AFTER REPAIR PROCEDURE • Perform the “After Repair Procedure” • Are any DTCs present?	Yes	Go to the applicable DTC inspection.
9		No	DTC troubleshooting completed.