DTC P0781:00

1-2 shift valve

DETECTION CONDITION

• Vehicle condition: During shifting from 3GR to 4GR

• Status: Detects that 1-2 shift valve does not move

• Period: Confirmed 1 time

FAIL-SAFE FUNCTION

• Inhibits learning control.

• Inhibits AAS mode.

• Inhibits the TCC control and slip control.

• Inhibits 4GR, 5GR, and 6GR.

• Inhibits 1GR and 2GR during manual shift control.

• Inhibits the slope control.

POSSIBLE CAUSE

• Deteriorated ATF

• ATF level low

• 1-2 shift valve stuck

• Control valve body malfunction

• Automatic transmission malfunction

• TCM malfunction

SYSTEM WIRING DIAGRAM

Not applicable

STEP

INSPECTION

ACTION

1

NOTE:

• Recording can be facilitated using the screen capture of the PC function.

• Record the freeze frame data/snap shot data.

—

Go to the next step.

2

• 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.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off, then ON (engine off or on).

• Perform the DTC inspection using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Are any other DTCs output?

Yes

Follow the applicable DTC inspection procedure, then go to the next step.

(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [TCM (SJ6A-EL)].)

No

Go to the next step.

4

• Switch the ignition off.

• Inspect the ATF condition.

• Transparent red: Normal

• Milky: Water mixed in fluid

• Reddish brown: Deteriorated ATF

• Is it normal?

  (See AUTOMATIC TRANSMISSION FLUID (ATF) INSPECTION [SJ6A-EL].)

Yes

Go to the next step.

No

Replace ATF, then go to Step 8.

(See AUTOMATIC TRANSMISSION FLUID (ATF) REPLACEMENT [SJ6A-EL].)

5

• Start the engine.

• Warm-up the automatic transmission until the ATF temperature is 57.5—62.5 °C {136—144 °F}.

• Is the ATF level within the specification?

  (See AUTOMATIC TRANSMISSION FLUID (ATF) LEVEL ADJUSTMENT [SJ6A-EL].)

Yes

Go to the next step.

No

Add ATF to the specified level, then go to Step 8.

(See AUTOMATIC TRANSMISSION FLUID (ATF) LEVEL ADJUSTMENT [SJ6A-EL].)

6

• Start the engine.

• Measure the line pressure.

  (See MECHANICAL SYSTEM TEST [SJ6A-EL].)

• Are the line pressures within the specifications?

Yes

Go to the next step.

No

Inspect or replace the part according to the result of the line pressure test, then go to Step 8.

7

• Switch the ignition off.

• Replace the control valve body.

  (See CONTROL VALVE BODY REMOVAL [SJ6A-EL].)

  (See CONTROL VALVE BODY INSTALLATION [SJ6A-EL].)

• Always reconnect all disconnected connectors.

• Clear the DTC using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Perform the following procedure to ensure that the DTC has been resolved:

• Start the engine.

• Warm-up the engine and transmission.

• Drive the vehicle in D position and make sure that the gears shift smoothly from 1GR to 6GR.

• Gradually slow down and stop the vehicle.

• Switch the ignition off.

• Start the engine.

• Drive the vehicle in D position and make sure that the gears shift smoothly from 1GR to 6GR.

• Perform the DTC inspection using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Is the same DTC present?

Yes

Replace the AT, then go Step 9.

(See AUTOMATIC TRANSMISSION REMOVAL/INSTALLATION [SJ6A-EL].)

No

Go to the next step.

8

• Always reconnect all disconnected connectors.

• Clear the DTC using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Perform the following procedure to ensure that the DTC has been resolved:

• Start the engine.

• Warm-up the engine and transmission.

• Drive the vehicle in D position and make sure that the gears shift smoothly from 1GR to 6GR.

• Gradually slow down and stop the vehicle.

• Switch the ignition off.

• Start the engine.

• Drive the vehicle in D position and make sure that the gears shift smoothly from 1GR to 6GR.

• Perform the DTC inspection using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Is the same DTC present?

Yes

Replace the TCM, then go to the next step.

(See TCM REMOVAL/INSTALLATION [SJ6A-EL].)

No

Go to the next step.

9

• Clear the DTC using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Perform the DTC inspection using the M-MDS.

  (See ON-BOARD DIAGNOSTIC SYSTEM DTC INSPECTION [TCM (SJ6A-EL)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See ON-BOARD DIAGNOSTIC SYSTEM DTC TABLE [TCM (SJ6A-EL)].)

No

DTC troubleshooting completed.