A750E Automatic Transmission System

A750E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0748: Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)
P0748 - Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)

DESCRIPTION

Shifting from 1st to 5th is performed in combination with the ON and OFF operation of the shift solenoid valves S1, S2, SR, SL1 and SL2 which are controlled by the ECM. 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 driven smoothly Fail-Safe Chart.





MONITOR DESCRIPTION

This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The ECM controls the 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 the DTC. Then the ECM performs the fail-safe function and turns the other functioning shift solenoid valves "ON/OFF". (If an open or short circuit is detected, the ECM cuts the current to the circuit.)

If the ECM detects an open or short in the shift solenoid valve SL1 circuit, the ECM determines that there is a malfunction Fail-Safe Chart.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





Condition (A)





Condition (B)





TYPICAL MALFUNCTION THRESHOLDS

When either condition below is met: Condition (A) or (B)

Condition (A)





Condition (B)





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.

HINT
The shift solenoid valve SL1 is turned ON/OFF normally when the shift lever is in D:





PROCEDURE

1. INSPECT TRANSMISSION WIRE (SL1)

(a) Disconnect the transmission wire connector from the transmission.





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

Standard Resistance:





NG -- INSPECT SHIFT SOLENOID VALVE SL1
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

(a) Connect the transmission wire connector to the transmission.





(b) Disconnect the connector from the ECM.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal

3. INSPECT SHIFT SOLENOID VALVE SL1

(a) Remove the shift solenoid valve SL1.





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

Standard Resistance:





(c) Connect the battery's positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating noise.

OK:

The solenoid makes an operating sound.

NG -- REPLACE SHIFT SOLENOID VALVE SL1

OK -- REPAIR OR REPLACE TRANSMISSION WIRE Removal