P0787

U340E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0787: Shift / Timing Solenoid Low (Shift Solenoid Valve ST)

DTC P0787 - Shift / Timing Solenoid Low (Shift Solenoid Valve ST)

DTC P0788 - Shift / Timing Solenoid High (Shift Solenoid Valve ST)

DESCRIPTION

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






MONITOR DESCRIPTION

When there is an open or short circuit in the shift solenoid valve circuit, the ECM detects the problem and the MIL comes on.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0787: Range check (Low resistance)





P0788: Range check (High resistance)





TYPICAL MALFUNCTION THRESHOLDS

P0787: Range check (Low resistance)





P0788: Range check (High resistance)





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE ST)




(a) Disconnect the transmission wire connector from the transaxle.
(b) Measure the resistance.
Standard resistance:






NG -- INSPECT SHIFT SOLENOID VALVE ST
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)




(a) Connect the transmission connector to the transaxle.
(b) Disconnect the ECM connector.
(c) Measure the resistance.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM
3. INSPECT SHIFT SOLENOID VALVE ST




(a) Remove shift solenoid valve ST.
(b) Measure the resistance.
Standard resistance:





(c) Connect the positive (+) lead to the terminal of the solenoid connector and the negative (-) lead to the solenoid body to check the solenoid valve operation.
OK:
The solenoid makes operating sounds.
NG -- REPLACE SHIFT SOLENOID VALVE ST
OK -- REPAIR OR REPLACE TRANSMISSION WIRE