Lexus IS250 IS220d GSE20 ALE20 - A960E AUTOMATIC TRANSMISSION
INSPECT TRANSMISSION WIRE (SL2)
CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
INSPECT SHIFT SOLENOID VALVE SL2
DTC P0778 Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)
DESCRIPTION
Shifting from 1st to 6th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR which is controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated smoothly .
| DTC No. | DTC Detection Condition | Trouble Area |
| P0778 | The ECM checks for an open or short in the shift solenoid valve SL2 circuit while driving and shifting gears. (1-trip detection logic) Output signal duty equals to 100%. (NOTE: SL2 output signal duty is less than 100% under normal condition.) |
Open or short in shift solenoid valve SL2 circuit Shift solenoid valve SL2 ECM |
Reference (Using an oscilloscope):
Check the waveform between the terminals SL2+ and SL2- of the ECM connector
- Standard:
- Refer to the illustration.
| Terminal | SL2+ - SL2- |
| Tool setting | 5 V/DIV., 1 ms./DIV. |
| Vehicle condition | Engine idle speed |
MONITOR DESCRIPTION
This DTC indicates an open or short in the shift solenoid valve SL2 circuit. 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 and illuminates the MIL and stores the DTC. And the ECM performs the fail-safe function and turns the other shift solenoid valves in good condition "ON/OFF". (In case of an open or short circuit, the ECM stops sending current to the circuit.)
While driving and shifting gears, if the ECM detects an open or short in the shift solenoid valve SL2 circuit, the ECM determines there is a malfunction .
WIRING DIAGRAM
INSPECTION PROCEDURE
- HINT:
| ECM command gearshift | 1st | 2nd | 3rd | 4th | 5th | 6th |
| Shift solenoid valve SL2 | ON | ON | ON | ON | OFF | OFF |
| 1.INSPECT TRANSMISSION WIRE (SL2) |
Disconnect the transmission wire connector from the transmission.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Specified Condition
20°C (68°F)10 (SL2+) - 2 (SL2-) 5.0 to 5.6 Ω
Measure the resistance according to the value(s) in the table below.
- Standard resistance (Check for short):
Tester Connection Specified Condition 10 (SL2+) - Body ground 10 kΩ or higher 2 (SL2-) - Body ground ↑
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| OK | |
| 2.CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM) |
Connect the transmission connector to the transmission.
Disconnect the connector from the ECM.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Specified Condition
20°C (68°F)E4-11 (SL2+) - E4-10 (SL2-) 5.0 to 5.6 Ω
Measure the resistance according to the value(s) in the table below.
- Standard resistance (Check for short):
Tester Connection Specified Condition E4-11 (SL2+) - Body ground 10 kΩ or higher E4-10 (SL2-) - Body ground ↑
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| OK | ||
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| 3.INSPECT SHIFT SOLENOID VALVE SL2 |
Remove the shift solenoid valve SL2.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
Tester Connection Specified Condition
20°C (68°F)1 - 2 5.0 to 5.6 Ω
Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector, then check the movement of the valve.
- OK:
- The solenoid makes an operating sound.
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| OK | ||
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