DESCRIPTION
Changing from 1st to 6th is performed by the ECM turning shift solenoid valves SL1, SL2, SL3 and SL4 on and off. If an open or short circuit occurs in any of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated.
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
---|---|---|---|---|---|
P0748 | Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1) | An open or short circuit (output signal duty is 0% or 100%) is detected by the ECM in the shift solenoid valve SL1 circuit while driving and shifting gears (SL1 output signal duty is more than 0% and less than 100% under normal conditions) (1 trip detection logic). |
|
Comes on | DTC stored |
MONITOR DESCRIPTION
This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The ECM commands gear shifts by turning the shift solenoid valves on or off. When there is an open or short circuit in any of the shift solenoid valve circuits, the ECM detects the problem and illuminates the MIL and stores the DTC. The ECM also performs the fail-safe function and turns the other normal shift solenoid valves on or 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 SL1 circuit, the ECM determines there is a malfunction.
WIRING DIAGRAM
*a | Shift Solenoid Valve SL1 |
*b | Transmission Wire |
CAUTION / NOTICE / HINT
Note
Perform registration and/or initialization when parts related to the automatic transmission are replaced.
Tech Tips
The following table shows normal operation of the shift solenoid valve SL1 when the shift lever is in D:
ECM commanded gear | 1st | 2nd | 3rd | 4th | 5th | 6th |
Shift solenoid valve SL1 | ON | ON | ON | ON | OFF | OFF |
After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
Perform the D Position Shift Test in Road Test.
Check for DTCs again.
PROCEDURE
INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL1)
*a | Component without harness connected (Transmission Wire) |
Disconnect the transmission wire connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
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Result | |||
---|---|---|---|
|
NG |
INSPECT SHIFT SOLENOID VALVE SL1 Click here |
OK |
CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
*a | Rear view of wire harness connector (to ECM) |
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
OK |
REPLACE ECM Click here |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT SHIFT SOLENOID VALVE SL1
*1 | Shift Solenoid Valve SL1 |
Remove shift solenoid valve SL1.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
|
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
OK | ||||
---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
OK |
REPLACE TRANSMISSION WIRE Click here |
NG |
REPLACE SHIFT SOLENOID VALVE SL1 Click here |