Toyota 4Runner: Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2) (P0976,P0977)

DESCRIPTION

Shifting from 1st to 5th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2 and SR, which is controlled by the ECM. If an open or short circuit occurs in one of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated smoothly. In case of an open or short circuit, the ECM stops sending current to the circuit. For details, refer to the fail-safe chart (See page ).

DTC Code	DTC Detection Condition	Trouble Area
P0976	The ECM detects a short in the solenoid valve S2 circuit 2 times when solenoid valve S2 is operated (1-trip detection logic).	Short in shift solenoid valve S2 circuit Shift solenoid valve S2 ECM
P0977	The ECM detects an open in the solenoid valve S2 circuit 2 times when solenoid valve S2 is not operated (1-trip detection logic).	Open in shift solenoid valve S2 circuit Shift solenoid valve S2 ECM

MONITOR DESCRIPTION

These DTCs indicate an open or short in the shift solenoid valve S2 circuit. 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. When the shift solenoid valve S2 is on, if its resistance is 8 Ω or less, the ECM determines there is a short in the shift solenoid valve S2 circuit.

When the shift solenoid valve S2 is off, if its resistance is 100 kΩ or higher, the ECM determines there is an open in the shift solenoid valve S2 circuit (See page ).

MONITOR STRATEGY

Related DTCs	P0976: Shift solenoid valve S2/Range check (Low resistance) P0977: Shift solenoid valve S2/Range check (High resistance)
Required sensors/Components	Shift solenoid valve S2
Frequency of operation	Continuous
Duration	0.128 sec. or more
MIL operation	Immediate
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not stored	None
Battery voltage	8 V or higher
Ignition switch	ON
Starter	OFF

P0976: Range Check (Low Resistance)

Shift solenoid valve S2

ON

P0977: Range Check (High Resistance)

Shift solenoid valve S2

OFF

TYPICAL MALFUNCTION THRESHOLDS

P0976: Range Check (Low Resistance)

Shift solenoid valve S2 resistance

8 Ω or less

P0977: Range Check (High Resistance)

Shift solenoid valve S2 resistance

100 kΩ or higher

COMPONENT OPERATING RANGE

Shift solenoid valve S2 resistance

11 to 15 Ω at 20°C (68°F)

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs (See page ).

HINT:

The shift solenoid valve S2 turns ON/OFF normally when the shift lever is in D.

ECM gear shift command	1st	2nd	3rd	4th	5th
Shift solenoid valve S2	OFF	ON	ON	OFF	OFF

PROCEDURE

1.	INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE S2)

(a) Disconnect the B32 transmission wire connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
15 (S2) - Body ground	20°C (68°F)	11 to 15 Ω

Text in Illustration

*a	Component without harness connected (Transmission Wire)

NG

GO TO STEP 3

OK

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

(a) Disconnect the B36 ECM connector.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
B36-33 (S2) - Body ground	20°C (68°F)	11 to 15 Ω

Text in Illustration

*a	Rear view of wire harness connector (to ECM)

OK

REPLACE ECM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT SHIFT SOLENOID VALVE S2

OK

REPAIR OR REPLACE TRANSMISSION WIRE

NG

REPLACE SHIFT SOLENOID VALVE S2