DESCRIPTION
The TCM uses the vehicle speed signal and signals from the transmission speed sensors (NC, NT) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).
Then the TCM compares the actual gear with the shift schedule in the TCM memory to detect mechanical problems of the shift solenoid valves and valve body.
DTC Code | DTC Detection Condition | Trouble Area |
---|---|---|
P0776 | Either condition is met (2-trip detection logic):
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MONITOR DESCRIPTION
The TCM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft speed, intermediate (counter) shaft speed and output shaft speed, the TCM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the TCM and the actual gear are not the same, the TCM illuminates the MIL and stores the DTC.
PROCEDURE
CHECK DTC OUTPUT (IN ADDITION TO DTC P0776)
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / DTC.
Read the DTCs using the intelligent tester.
Result | Proceed to |
---|---|
P0776 and other DTCs are output | A |
Only P0776 is output | B |
Tech Tips
If shift solenoid valve SL2 is stuck off, DTCs for several shift solenoid valves including the malfunctioning shift solenoid valve will be stored.
B |
INSPECT SHIFT SOLENOID VALVE SL2 Click here |
A |
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (RUNNING TEST)
Note
This test should always be performed with at least 2 people.
Warm up the engine.
Turn the ignition switch off.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / Active Test.
According to the display on the intelligent tester, perform the Active Test.
Tech Tips
Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem Click here.
Tester Display | Test Part | Control Range | Diagnostic Note |
---|---|---|---|
Control the Shift Position | Operate the shift solenoid valves and set each shift position |
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Can be used to check the operation of the shift solenoid valves. A 10-second interval is required between gear changes. Do not down-shift at high speeds. Doing so will damage the automatic transaxle. [Vehicle Condition]
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Note
This test can be conducted when the vehicle is stopped.
When shifting gears using the Active Test function, do not operate the accelerator pedal for 2 seconds before and after shifting gears.
Tech Tips
The gear commanded by the TCM is shown in the Data List / Shift Status display on the intelligent tester.
Check the vehicle speed and gear when the engine speed is 1000 rpm.
Tech Tips
Because the torque converter clutch has not engaged, it may be difficult to obtain the speeds specified in 4th, 5th and 6th gear, however a difference of speed should still be evident following each gear change.
1st | 2nd | 3rd | 4th | 5th | 6th |
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8 to 12 km/h (5 to 7.5 mph) | 15 to 19 km/h (9.3 to 11.8 mph) | 21 to 25 km/h (13.0 to 15.5 mph) | 31 to 35 km/h (19.3 to 21.7 mph) | 44 to 48 km/h (27.3 to 29.8 mph) | 52 to 56 km/h (32.3 to 34.8 mph) |
Compare the TCM commanded gear and the actual gear.
Result | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Tech Tips
*1: Neutral
*2: If shift solenoid valve SLT is stuck on, the line pressure will be low. Therefore, the amount of torque that can be transmitted by each gear is lower than the normal limit. When the engine power exceeds this lowered limit, the engine speed will increase freely.
*3: When shift solenoid valve SLT is stuck off, gear shifting is normal.
A |
GO TO DTC P0746 Click here |
B |
INSPECT SHIFT SOLENOID VALVE SL2 Click here |
C |
GO TO DTC P0796 Click here |
D |
GO TO DTC P2808 Click here |
E |
GO TO DTC P2714 Click here |
INSPECT SHIFT SOLENOID VALVE SL2
*1 | Component without harness connected (Shift Solenoid Valve SL2) |
Remove shift solenoid valve SL2.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
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Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
OK | ||||
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NG |
REPLACE SHIFT SOLENOID VALVE SL2 Click here |
OK |
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly Click here.
OK |
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There are no foreign objects on any valve. |
OK |
REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here |
NG |
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |
INSPECT SHIFT SOLENOID VALVE SL2
*1 | Component without harness connected (Shift Solenoid Valve SL2) |
Remove shift solenoid valve SL2.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
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Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
OK | ||||
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NG |
REPLACE SHIFT SOLENOID VALVE SL2 Click here |
OK |
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly Click here.
OK |
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There are no foreign objects on any valve. |
OK |
REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here |
NG |
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |