P0974

U341E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0973: Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1)

DTC P0973 - Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1)

DTC P0974 - Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)

DESCRIPTION

Shifting from 1st to 4th is performed in combination with "ON" and "OFF" of the shift solenoid valves S1 and S2 controlled by ECM. If an open or short circuit occurs in either of the solenoid valves, the ECM controls the remaining normal solenoid valve to allow the vehicle to be operated smoothly (Fail safe function).






MONITOR DESCRIPTION

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.) Fail-Safe Chart.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

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

PROCEDURE

1. INSPECT TRANSMISSION WIRE (S1)





(a) Disconnect the transmission wire connector from the transaxle.
(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 transaxle.
(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
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 positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.
Standard:
The solenoid makes an operating sound.
NG -- REPLACE SHIFT SOLENOID VALVE S1
OK -- REPAIR OR REPLACE TRANSMISSION WIRE