A750F Automatic Transmission

A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0973,P0974: Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1)
P0974 - Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)

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 .





MONITOR DESCRIPTION

These DTCs indicate an open or short in the shift solenoid valve S1 circuit. When there is an open or short circuit in any shift solenoid valve circuits, the ECM detects the problem, illuminates the MIL and stores the DTC. When the shift solenoid valve S1 is on, if the resistance is 8 Ohms or less, the ECM determines that there is a short malfunction in the shift solenoid valve S1 circuit.

When the shift solenoid valve S1 is off, if the resistance is 100 kOhms or more, the ECM determines that the shift solenoid valve S1 circuit is open .

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





P0973: Range Check (Low Resistance)





P0974: Range Check (High Resistance)





TYPICAL MALFUNCTION THRESHOLDS

P0973: Range Check (Low Resistance)





P0974: Range Check (High Resistance)





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs .

HINT
The shift solenoid valve S1 is turned on/off normally when the shift lever is in D:





PROCEDURE

1. INSPECT TRANSMISSION WIRE (S1)

(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 S1
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 S1

(a) Remove the shift solenoid valve S1.





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

Standard Resistance:





(c) Connect the battery's positive (+) lead to the terminal of the solenoid valve connector, and the negative (-) lead to the solenoid body. Then check that the valve moves and makes an operating noise.

OK:

The solenoid makes an operating sound.

NG -- REPLACE SHIFT SOLENOID VALVE S1

OK -- REPAIR OR REPLACE TRANSMISSION WIRE