ELECTRONIC CONTROLLED AUTOMATIC TRANSMISSION SYSTEM (for 1KD-FTV), Diagnostic DTC:P0973, P0974, P0976, P0977

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)
P0976 Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2)
P0977 Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)

DESCRIPTION

Shifting from 1st to O/D is performed in combination with the ON and OFF operation of the shift solenoid valves S1 and S2 controlled by the TCM. If an open or short circuit occurs in either of the shift solenoid valves, the TCM 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 TCM turns the other shift solenoid ON and OFF to shift to the gear positions shown in the table below. The TCM 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 TCM stops sending current to the circuit.

Position Normal Shift Solenoid Valve S1 Malfunctioning Shift Solenoid Valve 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 O/D
ON ON 2nd X ON 3rd OFF X O/D O/D
OFF ON 3rd X ON 3rd OFF X O/D O/D
OFF OFF O/D X OFF O/D OFF X O/D O/D
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 TCM 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

  • TCM
P0974 TCM 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

  • TCM
P0976 TCM 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

  • TCM
P0977 TCM 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

  • TCM

MONITOR DESCRIPTION

The TCM 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 TCM detects the problem, illuminates the MIL and stores a DTC.

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

In case of an open or short circuit, the TCM stop sending current to the circuit.

WIRING DIAGRAM

A01E1KXE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. A01E2EKE01

      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 - TCM)


    1. A01DWWJE05

      Disconnect the T19 TCM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      T19-18 (S1) - Body ground 20°C (68°F) 11 to 15 Ω
      T19-17 (S2) - Body ground 20°C (68°F) 11 to 15 Ω

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE TCM

  3. INSPECT SHIFT SOLENOID VALVE S1/S2


    1. A01DXMNE01

      Remove the shift solenoid valve S1/S2.

    2. Measure the resistance between the solenoid valve terminal and solenoid valve body.

      Standard resistance
      11 to 15 Ωat 20°C (68°F)

    3. Connect the battery's positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.

    4. Check the operating noise of the solenoid valve.

      OK
      Solenoid makes operating noise.

    NG

    REPLACE SHIFT SOLENOID VALVE S1/S2

    OK

    REPLACE TRANSMISSION WIRE