U340E AUTOMATIC TRANSMISSION / TRANSAXLE  AUTOMATIC TRANSAXLE SYSTEM  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 4th is performed through 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 solenoid valves, the ECM controls the remaining normal solenoid valve to allow the vehicle to be operated smoothly (fail safe function).

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0973 Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1) ECM detects short in 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


Comes on DTC stored
P0974 Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1) ECM detects open in 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


Comes on DTC stored

MONITOR DESCRIPTION

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 a DTC. The ECM performs the fail-safe function and turns the remaining normal shift solenoid valves "ON/OFF". (In the case of an open or short circuit, the ECM stops sending current to the circuit.)

Click hereDrivetrain>U340E AUTOMATIC TRANSMISSION / TRANSAXLE>AUTOMATIC TRANSAXLE SYSTEM>FAIL-SAFE CHART

WIRING DIAGRAM

C288592E25
5.594,1.25 5.833,1.469 0.24,0.219 10 false S1 5.323,1.375 5.542,1.625 0.219,0.25 10 false 56 5.74,2.927 6.146,3.115 0.406,0.188 10 false B56 5.74,3.125 6.177,3.354 0.438,0.229 10 false ECM 0.833,2.677 1.188,2.906 0.354,0.229 10 false B55 0.833,2.854 2.167,3.24 1.333,0.385 10 false Transmission Wire 1.479,1.729 3.313,2.094 1.833,0.365 10 false Shift Solenoid Valve S1 3.344,1.146 3.604,1.396 0.26,0.25 10 false S1 3.615,1.365 3.906,1.646 0.292,0.281 10 false 5

CAUTION / NOTICE / HINT

NOTICE:

Perform initialization when parts related to the automatic transaxle are replaced.

Click hereDrivetrain>U340E AUTOMATIC TRANSMISSION / TRANSAXLE>AUTOMATIC TRANSAXLE SYSTEM>PRECAUTION


PROCEDURE

1.INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1)
a.
C155864C27
0.792,2.698 1.01,1.729 false 0.25,0.292 0.563,0.448 0.313,0.156 10 false *a 0.698,2.74 1.302,3.042 0.604,0.302 10 false S1
*a Component without harness connected
(Transmission Wire)


Disconnect the transmission wire connector from the transaxle.


b.

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

Standard Resistance:
Tester Connection Condition Specified Condition
5 (S1) - Body ground 20°C (68°F) 11 to 15 Ω



Result:
Proceed to
OK
NG



OK

2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

NG

3.INSPECT SHIFT SOLENOID VALVE S1
2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
a.

Connect the transmission wire connector to the transaxle.


b.
C228647C16
2.656,0.823 3.042,1.073 0.385,0.25 1.417,2.625 1.292,1.729 false 0.177,0.167 0.49,0.323 0.313,0.156 10 false *a 2.74,0.854 3.063,1.073 0.323,0.219 10 false B56 1.333,2.656 1.667,2.865 0.333,0.208 10 false S1
*a Front view of wire harness connector
(to ECM)


Disconnect the ECM connector.


c.

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

Standard Resistance:
Tester Connection Condition Specified Condition
B56-56 (S1) - Body ground 20°C (68°F) 11 to 15 Ω



Result:
Proceed to
OK
NG



OK

REPLACE ECM

Click hereEngine / Hybrid System>1ZR-FE ENGINE CONTROL>ECM>COMPONENTS


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.INSPECT SHIFT SOLENOID VALVE S1
a.

Remove the shift solenoid valve S1.

C290980C03
0.281,0.24 0.594,0.396 0.313,0.156 10 false *1
*1 Shift Solenoid Valve S1 - -



b.

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

Standard Resistance:
Tester Connection Condition Specified Condition
Solenoid Connector (S1) - Solenoid Body (S1) 20°C (68°F) 11 to 15 Ω



c.

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

OK:

The solenoid makes an operating sound.



Result:
Proceed to
OK
NG



OK

REPAIR OR REPLACE TRANSMISSION WIRE

Click hereDrivetrain>U340E AUTOMATIC TRANSMISSION / TRANSAXLE>TRANSMISSION WIRE>COMPONENTS


NG

REPLACE SHIFT SOLENOID VALVE S1

Click hereDrivetrain>U340E AUTOMATIC TRANSMISSION / TRANSAXLE>VALVE BODY ASSEMBLY>COMPONENTS