Home › Drivetrain › Automatic Transmission/Transaxle › AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM
Last Modified: 11-27-2007 1.6 C
Service Category: Drivetrain Section: Automatic Transmission/Transaxle
Model Year: 2008 Model: LX570 Doc ID: RM000000W8603VX
Title: AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: DESCRIPTION (2008 LX570)

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 6th is performed in combination with ON and OFF operation of shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR, 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 operated safely. Also, the ECM stops sending current to the open or short circuited shift solenoid valve AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART (2008 LX570) .

DTC Code

DTC Detection Condition

Trouble Area

P0973

The ECM detects a short in the shift solenoid valve S1 circuit 2 times when shift solenoid valve S1 is operated (1 trip detection logic).
  • Short in shift solenoid valve S1 circuit
  • Shift solenoid valve S1
  • ECM

P0974

The ECM detects an open in the shift solenoid valve S1 circuit 2 times when shift solenoid valve S1 is not operated (1 trip detection logic).
  • Open in shift solenoid valve S1 circuit
  • Shift solenoid valve S1
  • ECM

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 circuit, the ECM detects the problem, illuminates the MIL and stores the DTC. When shift solenoid valve S1 is ON, if its resistance is 8 Ω or less, the ECM determines there is a short in the shift solenoid valve S1 circuit.

When shift solenoid valve S1 is OFF, if its resistance is 100 kΩ or higher, the ECM determines there is an open in the shift solenoid valve S1 circuit AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART (2008 LX570) .

MONITOR STRATEGY

Related DTCs

P0973: Shift solenoid valve S1/Range check (Low resistance)

P0974: Shift solenoid valve S1/Range check (High resistance)

Required sensors/Components

Shift solenoid valve S1

Frequency of operation

Continuous

Duration

0.128 sec. or more

MIL operation

1 driving cycle

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

All

The monitor will run whenever the following DTCs are not stored

None

P0973: Range Check (Low Resistance)

Shift solenoid valve S1

ON

P0974: Range Check (High Resistance)

Shift solenoid valve S1

OFF

TYPICAL MALFUNCTION THRESHOLDS

P0973: Range Check (Low Resistance)

Shift solenoid valve S1 resistance

8 Ω or less

P0974: Range Check (High Resistance)

Shift solenoid valve S1 resistance

100 kΩ or higher

COMPONENT OPERATING RANGE

Shift solenoid valve S1 resistance

11 to 15 Ω at 20°C (68°F)

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Shift solenoid valve S1 is turned ON/OFF normally when the shift lever is in D:

ECM gear shift command

1st

2nd

3rd

4th

5th

6th

Shift solenoid valve S1

OFF

ON

ON

ON

ON

ON

PROCEDURE

1.

INSPECT NO. 1 TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1)

(a) Disconnect the C39 No. 1 transmission wire connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

8 (S1) - Body ground

20°C (68°F)

11 to 15 Ω
OK

2.

CHECK HARNESS AND CONNECTOR (NO. 1 TRANSMISSION WIRE - ECM)


(a) Disconnect the C53 ECM connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

C53-7 (S1) - Body ground

20°C (68°F)

11 to 15 Ω
OK

3.

INSPECT SHIFT SOLENOID VALVE S1

(a) Remove shift solenoid valve S1.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Shift solenoid valve S1 connector terminal - Shift solenoid valve S1 body

20°C (68°F)

11 to 15 Ω

(c) Apply battery voltage (12 V) to the shift solenoid valve and check that the valve moves and makes an operating noise.

OK:

Measurement Condition

Specified Condition
  • Battery positive (+) → Shift solenoid valve S1 connector
  • Battery negative (-) → Shift solenoid valve S1 body

Valve moves and makes an operating noise
OK