DESCRIPTION
The 1-2 shift valve performs shifting to 1st gear and other gears.
DTC Code |
DTC Detection Condition |
Trouble Area |
---|---|---|
P0781 |
Gear required by the ECM does not match the actual gear when driving (2-trip detection logic). |
|
MONITOR DESCRIPTION
This DTC indicates that the 1-2 shift valve in the valve body is locked in the direction that the spring compresses.
The ECM commands gear shifts by turning the shift solenoid valves ON/OFF and controls the oil pressure applied to the valves in the valve body.
The ECM calculates the actual transmission gear by comparing the signals from the input speed sensor NT and output speed sensor SP2. The ECM can detect mechanical problems in the shift solenoids, valve body and automatic transmission (clutch, brake, gear, etc.). If the ECM detects that the actual gear position and commanded gear position are different, it will illuminate the MIL and store the DTC.
MONITOR STRATEGY
Related DTCs |
P0781: Valve body/Functional check |
Required sensors/Components |
Valve body, Automatic transmission assembly, Speed sensor (NT), Speed sensor (NO), Vehicle speed sensor, Throttle position sensor |
Frequency of operation |
Continuous |
Duration |
Condition (A) and (B): 0.4 sec. Condition (C): 3 sec. Condition (D): 0.5 sec. |
MIL operation |
2 driving cycles |
Sequence of operation |
None |
TYPICAL ENABLING CONDITIONS
All
The monitor will run whenever the following DTCs are not stored |
P0717 (Turbine speed sensor circuit) P0722 (Output speed sensor circuit) P0973, P0974 (Shift solenoid valve S1 circuit) P0976, P0977 (Shift solenoid valve S2 circuit) P0985, P0986 (Shift solenoid valve SR circuit) P0748 (Shift solenoid valve SL1 circuit) P0778 (Shift solenoid valve SL2 circuit) P0128 (ECT (Engine Coolant Temperature) sensor circuit) P0327, P0328, P0332, P0333 (KCS sensor circuit) |
ETCS (Electric Throttle Control System) |
Not system down |
Transmission position |
"D" |
Duration time from shifting "N" to "D" |
4 sec. or more |
ECT |
40°C (104°F) or higher |
Spark advance from max. retard timing by KCS control |
0° crankshaft angle or more |
Engine |
Starting |
ECM selected gear |
2nd |
Duration time from shift command of ECM |
2 sec. or more |
Vehicle speed |
2 km/h (1.2 mph) or more |
Output speed |
2nd → 1st down shift point or more |
Throttle valve opening angle |
6.5% or more at 2000 rpm (Conditions vary with engine speed) |
Calculated load value |
7.75% or more |
Following conditions is met: (a), (b), (c), (d) or (e) |
- |
(a) Turbine speed/Output speed (NT/NO) |
3.30 or more, and 7.50 or less (This means actual gear is 1st) |
(b) Turbine speed/Output speed (NT/NO) |
1.91 or more, and 2.35 or less (This means actual gear is 2nd) |
(c) Turbine speed/Output speed (NT/NO) |
1.28 or more, and 1.53 or less (This means actual gear is 3rd) |
(d) Turbine speed/Output speed (NT/NO) |
0.93 or more, and 1.07 or less (This means actual gear is 4th) |
(e) Turbine speed/Output speed (NT/NO) |
0.65 or more, and 0.79 or less (This means actual gear is 5th) |
ECM selected gear |
4th |
Duration time from shift command of ECM |
2 sec. or more |
Vehicle speed |
2 km/h (1.2 mph) or more |
Throttle valve opening angle |
6.5% or more at 2000 rpm (Conditions vary with engine speed) |
Calculated load value |
7.75% or more |
Following conditions is met: (a), (b), (c), (d) or (e) |
- |
(a) Turbine speed/Output speed (NT/NO) |
3.30 or more, and 7.50 or less (This means actual gear is 1st) |
(b) Turbine speed/Output speed (NT/NO) |
1.91 or more, and 2.35 or less (This means actual gear is 2nd) |
(c) Turbine speed/Output speed (NT/NO) |
1.28 or more, and 1.53 or less (This means actual gear is 3rd) |
(d) Turbine speed/Output speed (NT/NO) |
0.93 or more, and 1.07 or less (This means actual gear is 4th) |
(e) Turbine speed/Output speed (NT/NO) |
0.65 or more, and 0.79 or less (This means actual gear is 5th) |
Current ECM selected gear |
5th |
Last ECM selected gear |
4th |
Vehicle speed (During transition from 4th to 5th gear) |
Less than 100 km/h (62.2 mph) |
ECM selected gear |
5th |
Engine speed - Turbine speed (NE - NT) (After transition from 4th to 5th gear) |
150 rpm or less |
Vehicle speed (After transition from 4th to 5th gear) |
Less than 100 km/h (62.2 mph) |
TYPICAL MALFUNCTION THRESHOLDS
Both of the following conditions are met: Condition (A) and Condition (B), (C) or (D)
Condition (A)
Turbine speed/Output speed (NT/NO) |
3.30 or more, and 7.50 or less (This means actual gear is 1st) |
Turbine speed/Output speed (NT/NO) |
1.28 or more, and 1.53 or less (This means actual gear is 3rd) |
Turbine speed - Output speed x 4th gear ratio (NT - NO x 4th gear ratio) |
1000 rpm or more |
Turbine speed - Output speed x 5th gear ratio (NT - NO x 5th gear ratio) |
1000 rpm or more |
CAUTION / NOTICE / HINT
NOTICE:
Perform the universal trip to clear permanent DTCs (See page ).
PROCEDURE
1. |
CHECK DTC OUTPUT (IN ADDITION TO DTC P0781) |
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(e) Read the DTCs using the Techstream.
Result
Result |
Proceed to |
---|---|
Only P0781 is output |
A |
P0781 and other DTCs are output |
B |
HINT:
If any other codes besides P0781 are output, perform troubleshooting for those DTCs first.
B |
GO TO DTC CHART |
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM (RUNNING TEST) |
CAUTION:
This test should always be performed with at least 2 people.
NOTICE:
HINT:
Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.
(a) Connect the Techstream to the DLC3.
(b) Clear the DTCs (See page ).
(c) Warm up the engine.
(d) Enter the following menus: Powertrain / Engine and ECT / Active Test.
(e) According to the display on the Techstream, perform the Active Test.
HINT:
While driving, the shift position can be forcibly changed with the Techstream.
Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem (See page ).
Tester Display |
Test Part |
Control Range |
Diagnostic Note |
---|---|---|---|
Control the Shift Position |
Operate shift solenoid valve and set each shift position |
|
Possible to check operation of the shift solenoid valves. [Vehicle Condition] 50 km/h (31 mph) or less. |
HINT:
OK:
Gear position changes in accordance with the Techstream command.
NG |
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY |
|
3. |
PERFORM ACTIVE TEST USING TECHSTREAM (SHIFT SOLENOID VALVE SLT) |
NG |
REPLACE SHIFT SOLENOID VALVE SLT |
|
4. |
CLEAR DTC AND PERFORM RUNNING TEST |
(a) Clear the DTCs (See page ).
(b) Check for DTCs again after conducting the Monitor Drive Pattern (See page ).
OK:
No DTC output.
OK |
END |
NG |
REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY |
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
DTC Code
Detection Item
See page
11
Short in Motor LH
12
Short in Motor RH
21
Short to ...
Operating an iPod
Connecting an iPod enables you to enjoy music from the vehicle speakers.
Connecting an iPod
Pull up the lid.
Open the cover and connect an iPod using an iPod cable.
Turn on the power of the iPod if it is not turned on.
Press
.
Control panel
...