Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0740 - DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED Has FREEZE FRAME DATA been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY Check for related Service Bulletins and/or online repair information availability. Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	CHECK ATF CONDITION Turn ignition switch to OFF. Check ATF condition. Clear red: Normal Milky: Water mixed in fluid Reddish brown: Deteriorated ATF Is it okay? (See AUTOMATIC TRANSAXLE FLUID (ATF) INSPECTION )	Yes	Go to the next step.
3		No	If ATF color milky or reddish brown, replace ATF, then go to Step 5. (See AUTOMATIC TRANSAXLE FLUID (ATF) REPLACEMENT .)
4	CHECK ATF LEVEL Start engine. Warm up ATX. Is ATF level within specification? (See AUTOMATIC TRANSAXLE FLUID (ATF) LEVEL INSPECTION )	Yes	Go to the next step.
4		No	Adjust ATF level, then go to Step 9. (See AUTOMATIC TRANSAXLE FLUID (ATF) LEVEL INSPECTION )
5	INSPECT LINE PRESSURE Start engine. Measure line pressure. Specification Idle: 290-490 kPa {3.0-4.9 kgf/cm2,43-69 psi} Stall: 1,280-1,480 kPa {13.1-15.0 kgf/cm2, 187-213 psi} Is line pressure within specification? (See LINE PRESSURE TEST .)	Yes	Go to the next step.
5		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 AUTOMATIC TRANSAXLE REMOVAL/INSTALLATION .)
6	CLICK TEST OF SOLENOID VALVES Turn ignition switch to OFF. Disconnect the 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 from TCC solenoid valve and pressure control solenoid. Is there click sound?	Yes	Go to the next step.
6		No	Replace the TCC solenoid valve or pressure control solenoid, then go to Step 10. (See CONTROL VALVE BODY REMOVAL/INSTALLATION .)
7	INSPECT 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 RPM	Yes	Go to Step
7		No	Go to the next step.
8	INSPECT 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 the torque converter, then go to the next step.
8		No	Replace the control valve body, then go to the next step. (See CONTROL VALVE BODY REMOVAL/INSTALLATION .)
9	VERIFY 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 s or more. Vehicle speed (VSS PID): Within 10 km/h {6 mph}-87 km/h {54 mph} Gear position: 5GR TR switch position: D range TCC solenoid valve: ON Is there pending code present?	Yes	Replace the TCM, then go to the next step. (See TCM REMOVAL/INSTALLATION .)
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE .) Is there any DTC present?	Yes	Go to the applicable DTC inspection.
10		No	Troubleshooting completed.