Dtc P0787 Shift / Timing Solenoid Low (Shift Solenoid Valve St)
DESCRIPTION
MONITOR DESCRIPTION
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE ST)
CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
INSPECT 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.DTC No.
| DTC Detection Condition
| Trouble Area
|
P0787
| ECM detects short in solenoid valve ST circuit 4 times when solenoid valve ST is operated (1-trip detection logic).
| - Wire harness or connector
- Transmission wire
- Shift solenoid valve ST
- ECM
|
P0788
| ECM detects open in solenoid valve ST circuit 4 times when solenoid valve ST is not operated (1-trip detection logic).
| - Wire harness or connector
- Transmission wire
- Shift solenoid valve ST
- ECM
|
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
Related DTCs
| P0787: Shift timing solenoid/Range check (Low resistance)
P0788: Shift timing solenoid/Range check (High resistance)
|
Required sensors/Components
| Shift solenoid valve ST
|
Frequency of operation
| Continuous
|
Duration
| 0.128 seconds
|
MIL operation
| Immediate
|
Sequence of operation
| None
|
TYPICAL ENABLING CONDITIONS
P0787: Range check (Low resistance)The monitor runs whenever the following DTCs are not present
| None
|
Solenoid
| ON
|
Time after solenoid OFF to ON
| 0.008 seconds or more
|
Battery voltage
| 8 V or more
|
Ignition switch
| ON
|
Starter
| OFF
|
P0788: Range check (High resistance)The monitor runs whenever the following DTCs are not present
| None
|
Solenoid
| OFF
|
Time after solenoid ON to OFF
| 0.008 seconds or more
|
Battery voltage
| 8 V or more
|
Ignition switch
| ON
|
Starter
| OFF
|
TYPICAL MALFUNCTION THRESHOLDS
P0787: Range check (Low resistance)Shift solenoid valve ST resistance
| 8 Ω or less
|
P0788: Range check (High resistance)Shift solenoid valve ST resistance
| 100 kΩ or more
|
COMPONENT OPERATING RANGE
Shift solenoid valve ST resistance
| 11 to 15 Ω at 20°C (68°F)
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- Perform the universal trip to clear permanent DTCs (YARIS_NCP93 RM000000W770MGX.html).
| 1.INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE ST) |
Disconnect the transmission wire connector from the transaxle.
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
|
Text in Illustration*a
| Component without harness connected
(Transmission Wire)
|
| 2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM) |
Connect the transmission connector to the transaxle.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
C20-80 (ST) - Body ground
| 20°C (68°F)
| 11 to 15 Ω
|
Text in Illustration*a
| Front view of wire harness connector
(to ECM)
|
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 3.INSPECT SHIFT SOLENOID VALVE ST |
Remove shift solenoid valve ST.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
1 - Solenoid Body
| 20°C (68°F)
| 11 to 15 Ω
|
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.
Text in Illustration*a
| Component without harness connected
(Shift Solenoid Valve ST)
|
