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

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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)
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DESCRIPTION

Shifting from 1st to 5th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2 and SR, which is controlled by the ECM. If an open or short circuit occurs in one of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly. In case of an open or short circuit, the ECM stops sending current to the circuit. For details, refer to the fail-safe chart (Click here).

DTC Code DTC Detection Condition Trouble Area
P0973 The ECM detects a short in the solenoid valve S1 circuit 2 times when 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 solenoid valve S1 is not operated (1-trip detection logic).

  • Open in shift solenoid valve S1 circuit

  • Shift solenoid valve S1

  • ECM
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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).

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WIRING DIAGRAM

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INSPECTION PROCEDURE

Tip:

The shift solenoid valve S1 turns ON/OFF normally when the shift lever is in D.

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


  1. Click here

    INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1)


    1. A01DP6IE04

      Disconnect the C30 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
      Table 1. Text in Illustration
      *a

      Component without harness connected

      (Transmission Wire)

  2. Click here

    CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)


    1. A01DPQRE08

      Disconnect the C35 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C35-36 (S1) - Body ground 20°C (68°F) 11 to 15 Ω
      Table 2. Text in Illustration
      *a

      Rear view of wire harness connector

      (to ECM)

  3. Click here

    INSPECT SHIFT SOLENOID VALVE S1


    1. A01DLWJE01

      Remove 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 operating noise
      Table 3. Text in Illustration
      *a

      Component without harness connected

      (Shift Solenoid Valve S1)

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    REPAIR OR REPLACE TRANSMISSION WIREClick here

  5. Click here

    REPLACE ECMClick here

  6. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. Click here

    REPLACE SHIFT SOLENOID VALVE S1Click here