AUTOMATIC TRANSMISSION SYSTEM (for 1VD-FTV with DPF), Diagnostic DTC:P0748

DESCRIPTION

Shifting from 1st to 6th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR, which are controlled by the ECM. If an open or short circuit occurs in the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated safely (Click here).

MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The ECM commands gear shifts by turning the shift solenoid valves ON/OFF. When there is an open or short circuit in any shift solenoid valve circuit, the ECM detects the problem, illuminates the MIL and stores the DTC. Also, the ECM performs the fail-safe function and turns the other normal shift solenoid valves ON/OFF. In case of an open or short circuit, the ECM stops sending current to the open or short circuited solenoid.

While driving and shifting between 4th and 5th gears, if the ECM detects an open or short in the shift solenoid valve SL1 circuit, the ECM determines that there is a malfunction (Click here).

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   INSPECT NO. 1 TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL1)

   
   
   1. 

      Disconnect the No. 1 transmission wire connector.

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition 11 (SL1+) - 3 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω 11 (SL1+) - Body ground Always 10 kΩ or higher 3 (SL1-) - Body ground Always 10 kΩ or higher

      Table 1. Text in Illustration

      *a	Component without harness connected (No. 1 Transmission Wire)

   
   
   • OKClick here
   • NGClick here
2. Click here

   CHECK HARNESS AND CONNECTOR (NO. 1 TRANSMISSION WIRE - ECM)

   
   

   1. Disconnect the ECM connector.

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Table 2. for LHD Tester Connection Condition Specified Condition C45-13 (SL1+) - C45-12 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω C45-13 (SL1+) - Body ground Always 10 kΩ or higher C45-12 (SL1-) - Body ground Always 10 kΩ or higher
      Table 3. for RHD Tester Connection Condition Specified Condition C46-13 (SL1+) - C46-12 (SL1-) 20°C (68°F) 5.0 to 5.6 Ω C46-13 (SL1+) - Body ground Always 10 kΩ or higher C46-12 (SL1-) - Body ground Always 10 kΩ or higher

      Table 4. Text in Illustration

      *1	for LHD
      *2	for RHD
      *a	Front view of wire harness connector (to ECM)

   
   
   • OKClick here
   • NGClick here
3. Click here

   INSPECT SHIFT SOLENOID VALVE SL1

   
   
   1. 

      Remove the shift solenoid valve SL1.

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition 1 - 2 20°C (68°F) 5.0 to 5.6 Ω

   3. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

      OK
      Measurement Condition Specified Condition Battery positive (+) with a 21 W bulb → Terminal 1 Battery negative (-) → Terminal 2 Valve moves and makes an operating noise

      Table 5. Text in Illustration

      *a	Component without harness connected (Shift Solenoid Valve SL1)

   
   
   • OKClick here
   • NGClick here
4. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

5. Click here

   REPLACE ECMClick here

6. Click here

   REPLACE SHIFT SOLENOID VALVE SL1Click here

7. Click here

   REPAIR OR REPLACE NO. 1 TRANSMISSION WIREClick here