U340E AUTOMATIC TRANSMISSION / TRANSAXLE  AUTOMATIC TRANSAXLE SYSTEM  P0787  Shift / Timing Solenoid Low (Shift Solenoid Valve ST)  P0788  Shift / Timing Solenoid High (Shift Solenoid Valve ST)  


DESCRIPTION

The shift solenoid valve ST is switched OFF-ON-OFF in accordance with signals from the ECM when up-shifting and down-shifting between 3rd and 4th gear. This reduces the shock of gear shifting between these positions.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0787 Shift / Timing Solenoid Low (Shift Solenoid Valve ST) ECM detects short in solenoid valve ST circuit 2 times when solenoid valve ST is operated (1-trip detection logic)
·

Short in shift solenoid valve ST circuit

·

Shift solenoid valve ST

·

ECM


Comes on DTC stored
P0788 Shift / Timing Solenoid High (Shift Solenoid Valve ST) ECM detects open in solenoid valve ST circuit 2 times when solenoid valve ST is not operated (1-trip detection logic)
·

Open in shift solenoid valve ST circuit

·

Shift solenoid valve ST

·

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.)

WIRING DIAGRAM

C288592E24
5.594,1.24 5.833,1.458 0.24,0.219 10 false ST 5.323,1.354 5.542,1.604 0.219,0.25 10 false 59 5.74,2.927 6.146,3.115 0.406,0.188 10 false B56 5.74,3.094 6.177,3.323 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 ST 3.323,1.135 3.583,1.385 0.26,0.25 10 false ST 3.625,1.365 3.917,1.646 0.292,0.281 10 false 2

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 ST)
a.
C155861C10
2.125,1.531 2.448,1.01 false 0.229,0.302 0.542,0.458 0.313,0.156 10 false *a 2.51,0.771 2.823,0.927 0.313,0.156 10 false ST
*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
2 (ST) - 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 ST
2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
a.

Connect the transmission wire connector to the transaxle.


b.
C228647C15
2.677,0.823 3.063,1.073 0.385,0.25 1.677,2.625 1.552,1.729 false 0.177,0.167 0.49,0.323 0.313,0.156 10 false *a 2.75,0.854 3.073,1.073 0.323,0.219 10 false B56 1.594,2.656 1.927,2.865 0.333,0.208 10 false ST
*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 (Check for short):
Tester Connection Condition Specified Condition
B56-59 (ST) - 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 ST
a.

Remove the shift solenoid valve ST.

C290982C01
0.146,0.094 0.552,0.417 0.406,0.323 10 false *1
*1 Shift Solenoid Valve ST - -



b.

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

Standard Resistance:
Tester Connection Condition Specified Condition
Solenoid Connector (ST) - Solenoid Body (ST) 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 ST

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