- Short in shift solenoid valve S1 circuit
- Shift solenoid valve S1
- ECM
| Last Modified: 7-3-2017 | 6.8:8.0.40 | Doc ID: RM000000W8601ZX |
| Model Year Start: 2007 | Model: LX470 | Prod Date Range: [08/2006 - ] |
| Title: A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0973,P0974; Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1); 2007 MY LX470 [08/2006 - ] | ||
|
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 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
![2007 MY LX470 [08/2006 - ]; A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART](../../../../stylegraphics/info.gif "2007 MY LX470 [08/2006 - ]; A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: FAIL-SAFE CHART")
.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P0973 |
ECM detects short in solenoid valve S1 circuit 2 times when solenoid valve S1 is operated (1 trip detection logic) |
|
|
P0974 |
ECM detects open in solenoid valve S1 circuit 2 times when solenoid valve S1 is not operated (1 trip detection logic) |
|
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 and illuminates the MIL and stores the DTC. When the shift solenoid valve S1 is ON, if resistance is 8 Ω or less, the ECM determines that there is a short in the shift solenoid valve S1 circuit.
When the shift solenoid valve S1 is OFF, if resistance is 100 kΩ or more, the ECM determines that there is an open in the shift solenoid valve S1 circuit
.
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 |
Immediately |
|
Sequence of operation |
None |
TYPICAL ENABLING CONDITIONS
All
|
The monitor will run whenever this DTC is not present. |
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 more |
COMPONENT OPERATING RANGE
|
Shift solenoid valve S1 |
Resistance: 11 to 15 Ω at 20°C (68°F) |
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
The shift solenoid valve S1 turns ON/OFF normally when the shift lever is on D:
|
ECM gear shift command |
1st |
2nd |
3rd |
4th |
5th |
|
Shift solenoid valve S1 |
ON |
ON |
OFF |
OFF |
OFF |
PROCEDURE
|
1. |
INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE S1) |
|
(a) Disconnect the E1 wire connector. |
|
(b) Measure the resistance of the transmission wire.
Standard resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
8 - Body ground |
20°C (68°F) |
11 to 15 Ω |
| NG |
|
|
|
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 |
|---|---|---|
|
E7-11 (S1) - Body ground |
20°C (68°F) |
11 to 15 Ω |
| NG |
|
| OK |
|
|
3. |
INSPECT SHIFT SOLENOID VALVE S1 |
|
(a) Remove the shift solenoid valve S1. (b) Measure the resistance of the solenoid valve. Standard resistance: 5.0 to 5.6 Ωat 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 operating noise. |
|
| NG |
|
| OK |
|
|
|