AUTOMATIC TRANSMISSION SYSTEM (for 1UR-FE), Diagnostic DTC:P0973, P0974

DTC Code DTC Name
P0973 Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1)
P0974 Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)

DESCRIPTION

Shifting from 1st to 6th is performed in combination with 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 any of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated safely. Also, the ECM stops sending current to the open or short circuited solenoid Click here.

DTC Code DTC Detection Condition Trouble Area
P0973 The ECM detects a short in the solenoid valve S1 circuit 2 times when the solenoid valve S1 is operated (1 trip detection logic).

  • Short in shift solenoid valve S1 circuit

  • Shift solenoid valve S1

  • ECM
P0974 The ECM detects an open in the solenoid valve S1 circuit 2 times when the solenoid valve S1 is not operated (1 trip detection logic).

  • Open in shift solenoid valve S1 circuit

  • Shift solenoid valve S1

  • ECM

MONITOR DESCRIPTION

These DTCs indicate an open or short in the shift solenoid valve S1 circuit. 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. When the shift solenoid valve S1 is ON, if its resistance is 8 Ω or less, the ECM determines there is a short in the shift solenoid valve S1 circuit.

When the shift solenoid valve S1 is OFF, if its resistance is 100 kΩ or higher, the ECM determines there is an open in the shift solenoid valve S1 circuit Click here.

WIRING DIAGRAM

A015B6JE14

INSPECTION PROCEDURE

Tech Tips

The shift solenoid valve S1 is turned ON/OFF normally when the shift lever is in D:

ECM gear shift command 1st 2nd 3rd 4th 5th 6th
Shift solenoid valve S1 OFF ON ON ON ON ON

PROCEDURE


  1. INSPECT NO. 1 TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1)


    1. A015739E33
      Text in Illustration
      *a

      Component without harness connected

      (No. 1 Transmission Wire)

      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
      8 (S1) - Body ground 20°C (68°F) 11 to 15 Ω

    NG

    Click here

    OK

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

    A015CW9E52
    Text in Illustration
    *1 for LHD
    *2 for RHD
    *a

    Front view of wire harness connector

    (to ECM)

    1. Disconnect the ECM connector.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      C45-7 (S1) - Body ground 20°C (68°F) 11 to 15 Ω
      for RHD
      Tester Connection Condition Specified Condition
      C46-7 (S1) - Body ground 20°C (68°F) 11 to 15 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  3. INSPECT SHIFT SOLENOID VALVE S1


    1. A015CSCE04
      Text in Illustration
      *a

      Component without harness connected

      (Shift Solenoid Valve S1)

      Remove the shift solenoid valve S1.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Shift solenoid valve S1 connector terminal - Shift solenoid valve S1 body 20°C (68°F) 11 to 15 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 (+) → Shift solenoid valve S1 connector

      • Battery negative (-) → Shift solenoid valve S1 body

      		 Valve moves and makes an operating noise

    NG

    REPLACE SHIFT SOLENOID VALVE S1 Click here

    OK

    REPAIR OR REPLACE NO. 1 TRANSMISSION WIRE Click here