DTC    P0729    Gear 6 Incorrect Ratio

for Preparation Click here

DESCRIPTION

HINT:

1. Gear positions in the event of a solenoid valve mechanical problem:
   
   

   ECM gear shift command	1st	2nd	3rd	4th	5th	6th
   Actual gear position under malfunction	1st	2nd	3rd	4th	5th	4th

2. Gear position during fail-safe operation:
   If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.
   
   

   Gear position under normal conditions	1st	2nd	3rd	4th	5th	6th
   Actual gear position under fail-safe mode	1st	2nd	3rd	3rd	3rd	3rd

MONITOR DESCRIPTION

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

INSPECTION PROCEDURE

NOTICE:

Perform the universal trip to clear permanent DTCs (Click here).

1. Connect the Techstream to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the Techstream on.
   

4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
   

5. Read the DTCs using the Techstream.
   

   Result 

   Result	Proceed to
   Only P0729 is output	A
   P0729 and other DTCs are output	B

   HINT:

   If any other codes besides P0729 are output, perform troubleshooting for those DTCs first.

B	GO TO DTC CHART (Click here)

A

CAUTION:

This test should always be performed with at least 2 people.

NOTICE:

1. Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).
   
2. Perform the test with the A/C turned off.
   

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

1. Connect the Techstream to the DLC3.
   

2. Clear the DTC (Click here).
   

3. Warm up the engine.
   

4. Enter the following menus: Powertrain / Engine and ECT / Active Test.
   

5. According to the display on the Techstream, perform the Active Test.
   

   HINT:

   While driving, the shift position can be forcibly changed with the Techstream.

   Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem (Click here).

   
   

   Engine and ECT: 

   Tester Display	Test Part	Control Range	Diagnostic Note
   Control the Shift Position	Operate shift solenoid valve and set each shift position	Press "→" button: Shift up Press "←" button: Shift down	Possible to check operation of shift solenoid valves [Vehicle Condition] 50 km/h (30 mph) or less

   HINT:

   1. This test can be conducted when the vehicle speed is 50 km/h (30 mph) or less.
      
   2. The 4th to 5th and 5th to 6th up-shifts must be performed with the accelerator pedal released.
      
   3. The 6th to 5th and 5th to 4th down-shifts must be performed with the accelerator pedal released.
      
   4. Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
      
   5. The shift position commanded by the ECM is shown in the Data List display on the Techstream.
      
   6. Gear positions in the event of a solenoid valve mechanical problem:
      
      

      Techstream gear shift command	1st	2nd	3rd	4th	5th	6th
      Actual gear position under malfunction	1st	2nd	3rd	4th	5th	4th

   OK:

   Gear position changes in accordance with the Techstream command.
   

NG	REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY (Click here)

OK

NOTICE:

1. Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).
   
2. Be careful to prevent SST's hose from interfering with the exhaust pipe.
   
3. Perform the test with the A/C OFF.
   

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

1. Remove the test plug on the transmission case center right side and connect SST.
   

SST

09992-00095   (09992-00231, 09992-00271)

2. Connect the Techstream to the DLC3.
   

3. Start the engine and warm it up.
   

4. Measure the line pressure with SST.
   

5. Turn the Techstream on.
   

6. Enter the following menus: Powertrain / Engine and ECT / Active Test.
   

7. According to the display on the Techstream, perform the Active Test.
   

8. Measure the line pressure.
   
   

   Engine and ECT: 

   Tester Display	Test Part	Control Range	Diagnostic Note
   Activate the Solenoid (SLT)*	Operate shift solenoid SLT and raise line pressure	ON or OFF HINT: OFF: Line pressure up (when Active Test "Activate the Solenoid (SLT)" is performed, ECM commands SLT solenoid to turn OFF) ON: No action (normal operation)	[Vehicle Condition] Vehicle stopped Engine idling

   HINT:

   *: Activate the Solenoid (SLT) in the Active Test is performed to check the line pressure changes by connecting SST to the automatic transmission, which is used in the Hydraulic Test (Click here) as well. Note that the pressure values in the Active Test and Hydraulic Test are different.

   OK:

   The line pressure changes as specified when performing the Active Test.
   

NG	REPLACE SHIFT SOLENOID VALVE SLT (Click here)

OK

1. Clear the DTC (Click here).
   

2. Check for DTC again after conducting the MONITOR DRIVE PATTERN (Click here).
   

   OK:

   No DTC code output.
   

NG	REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY (Click here)

OK
END