AUTOMATIC TRANSMISSION SYSTEM, Diagnostic DTC:P0973/62, P0974/62, P0976/63, P0977/63

DTC Code DTC Name
P0973/62 Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1)
P0974/62 Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)
P0976/63 Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2)
P0977/63 Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)

DESCRIPTION

Shifting from 1st to 4th is performed in combination with the ON and OFF operation of the shift solenoid valves S1 and S2 controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated safely (fail-safe function).

Fail-safe function:

If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid valve SL OFF at the same time. If both solenoids are malfunctioning, electronic hydraulic control does not operate and must be performed manually. Manual shifting as shown in the following table must be performed.

In case of a short circuit, the ECM stops sending current to the circuit.

Position Normal Shift Solenoid S1 Malfunctioning Shift Solenoid S2 Malfunctioning Both Solenoids Malfunctioning
Solenoid valve Gear Solenoid valve Gear Solenoid valve Gear Gear when shift selector is manually operated
S1 S2 S1 S2 S1 S2
D ON OFF 1st X ON 3rd ON X 1st 4th
ON ON 2nd X ON 3rd OFF X 4th 4th
OFF ON 3rd X ON 3rd OFF X 4th 4th
OFF OFF 4th X OFF 4th OFF X 4th 4th
2 ON OFF 1st X ON 3rd ON X 1st 3rd
ON ON 2nd X ON 3rd OFF X 3rd 3rd
OFF ON 3rd X ON 3rd OFF X 3rd 3rd
L ON OFF 1st X OFF 1st ON X 1st 1st
ON ON 2nd X ON 2nd ON X 1st 1st

Tech Tips

X: Malfunction

DTC No. DTC Detection Condition Trouble Area
P0973/62 ECM detects short in solenoid valve S1 circuit 4 times when solenoid valve S1 is operated (1 trip detection logic)

  • Short in shift solenoid valve S1 circuit

  • Shift solenoid valve S1

  • ECM
P0974/62 ECM detects open in solenoid valve S1 circuit 4 times when solenoid valve S1 is not operated (1 trip detection logic)

  • Open in shift solenoid valve S1 circuit

  • Shift solenoid valve S1

  • ECM
P0976/63 ECM detects short in solenoid valve S2 circuit 4 times when solenoid valve S2 is operated (1 trip detection logic)

  • Short in shift solenoid valve S2 circuit

  • Shift solenoid valve S2

  • ECM
P0977/63 ECM detects open in solenoid valve S2 circuit 4 times when solenoid valve S2 is not operated (1 trip detection logic)

  • Open in shift solenoid valve S2 circuit

  • Shift solenoid valve S2

  • ECM

MONITOR DESCRIPTION

The ECM controls gear shift 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 a DTC.

The ECM performs the fail-safe function and turns the normally functioning shift solenoid valve ON/OFF.

In case of an open or short circuit, the ECM stops sending current to the circuit.

WIRING DIAGRAM

A01J3LEE03

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1/S2)


    1. A01J35OE01

      Disconnect the E1 wire connector.

    2. Measure the resistance of the transmission wire.

      Standard resistance
      Tester Connection Condition Specified Condition
      4 (S1) - Body ground 20°C (68°F) 11 to 15 Ω
      8 (S2) - Body ground 20°C (68°F) 11 to 15 Ω

    NG

    INSPECT SHIFT SOLENOID VALVE S1/S2 Click here

    OK

  2. CHECK WIRE HARNESS (SHIFT SOLENOID VALVE S1/S2 - ECM)


    1. A01J4OSE26

      Disconnect the E10 ECM connector.

    2. Measure the resistance of the wire harness side connector.

      Standard resistance
      Tester Connection Condition Specified Condition
      E10-9 (S1) - Body ground 20°C (68°F) 11 to 15 Ω
      E10-8 (S2) - Body ground 20°C (68°F) 11 to 15 Ω

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM

  3. INSPECT SHIFT SOLENOID VALVE S1/S2


    1. A01J5WFE01

      Remove the shift solenoid valve S1/S2.

    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
      Shift solenoid valve S2 connector terminal - Shift solenoid valve S2 body 20°C (68°F) 11 to 15 Ω

    3. Connect the battery's positive (+) lead to the terminal of the solenoid valve connector, and the negative (-) lead to the solenoid valve body. Then check that the valve moves and makes an operating noise.

      OK
      Valve moves and makes an operating noise.

    NG

    REPLACE SHIFT SOLENOID VALVE S1/S2

    OK

    REPLACE TRANSMISSION WIRE