Last Modified: 4-30-2014 6.6 C Doc ID: RM000000W8700HX
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0976,P0977; Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2); 2006 MY LX470 [05/2005 -        ]

DTC

P0976

Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2)

DTC

P0977

Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)

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 the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated safely 2006 MY LX470 [05/2005 -        ]; A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART .

DTC No.

DTC Detection Condition

Trouble Area

P0976

ECM detects short in 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

ECM detects open in 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 and illuminates the MIL and stores the DTC. When the shift solenoid valve S2 is ON, if resistance is 8 Ω or less, the ECM determines that there is a short in the shift solenoid valve S2 circuit.

When the shift solenoid valve S2 is OFF, if resistance is 100 kΩ or more, the ECM determines that there is an open in the shift solenoid valve S2 circuit 2006 MY LX470 [05/2005 -        ]; A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART .

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

Immediately

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

P0976: Range check (Low resistance)

The monitor will run whenever this DTC is not present.

None

Shift solenoid valve S2

ON

P0977: Range check (High resistance)

The monitor will run whenever this DTC is not present.

None

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 more

COMPONENT OPERATING RANGE

Shift solenoid valve S2

Resistance: 11 to 15 Ω at 20°C (68°F)

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

The shift solenoid valve S2 turns ON/OFF normally when the shift lever is on 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 E1 wire connector.

(b) Measure the resistance of the transmission wire.

Standard resistance:

Tester Connection

Condition

Specified Condition

15 - Body ground

20°C (68°F)

11 to 15 Ω

NG

GO TO STEP 3

OK

2.

CHECK WIRE HARNESS (TRANSMISSION WIRE - ECM)

(a) Disconnect the E7 ECM connector.

(b) Measure the resistance of the wire harness side connector.

Standard resistance:

Tester Connection

Condition

Specified Condition

E7-10 (S2) - Body ground

20°C (68°F)

11 to 15 Ω

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

REPLACE ECM

3.

INSPECT SHIFT SOLENOID VALVE S2

(a) Remove the shift solenoid valve S2.

(b) Measure the resistance between the solenoid valve terminal and solenoid valve body.

Standard resistance:

11 to 15 Ω at 20°C (68°F)

(c) Connect the battery's positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.

OK:

Solenoid makes an operating noise.

NG

REPLACE SHIFT SOLENOID VALVE S2

OK

REPAIR OR REPLACE TRANSMISSION WIRE