SYSTEM DESCRIPTION
The ECM uses the vehicle speed signal and signals from the transmission revolution sensors (NT, SP2) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear).
The ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, transmission valve body assembly or automatic transmission assembly (clutch, brake or gear etc.).
DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory |
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P2808 | Pressure Control Solenoid "G" Performance (Shift Solenoid Valve SL4) | Either condition is met (2 trip detection logic):
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Comes on | DTC stored |
MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves on and off. According to the input turbine speed and output shaft speed, the ECM detects the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). When the gear commanded by the ECM and the actual gear are not the same, the ECM illuminates the MIL and stores the DTC.
CAUTION / NOTICE / HINT
Note
Perform registration and/or initialization when parts related to the automatic transmission are replaced.
Tech Tips
After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
Perform the D Position Shift Test in Road Test.*1
Turn the ignition switch off.
Perform step (*1) again.
Check for DTCs again.
PROCEDURE
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2808)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs using the GTS.
Result | ||||||
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Tech Tips
If a solenoid is stuck off, DTCs for several solenoids including the malfunctioning solenoid will be detected.
A |
GO TO STEP 3 Click here |
B |
PERFORM ACTIVE TEST USING GTS (CONTROL THE SHIFT POSITION)
Note
This test should always be performed with at least 2 people.
Warm up the engine.
Turn the ignition switch off.
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Active Test.
According to the display on the GTS, perform the Active Test.
Tech Tips
Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem.
Tester Display | Measurement Item | Control Range | Diagnostic Note |
---|---|---|---|
Control the Shift Position | Operates the shift solenoid valves to allow gears to be selected manually. |
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Can be used to check the operation of the shift solenoid valves. Up-shifts and down-shifts should be performed consecutively. A 10 second interval is required between gear changes. Do not down-shift at high speeds. Doing so will damage the automatic transmission. [Vehicle Condition]
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Tester Display |
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Control the Shift Position |
Tech Tips
This test can be conducted when the vehicle speed is 50 km/h (30 mph) or less.
The 4th to 5th and 5th to 6th up-shift must be performed with the accelerator pedal released.
The 6th to 5th and 5th to 4th down-shift must be performed with the accelerator pedal released.
Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
The gear commanded by the ECM is shown in the Data List / Shift Status display on the GTS.
Compare the ECM 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 CHART (RELATED SHIFT SOLENOID VALVE SL1 PERFORMANCE DTC P0746) Click here |
B |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL2 PERFORMANCE DTC P0776) Click here |
C |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL3 PERFORMANCE DTC P0796) Click here |
E |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SLT PERFORMANCE DTC P2714) Click here |
D |
INSPECT SHIFT SOLENOID VALVE SL4
*1 | Shift Solenoid Valve SL4 |
Remove shift solenoid valve SL4.
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.
Measurement Condition | Specified Condition |
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Valve moves and makes an operating noise. |
Result | |||
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NG |
REPLACE SHIFT SOLENOID VALVE SL4 Click here |
OK |
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly.
OK |
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There is no foreign matter on each valve and they operate smoothly. |
Result | |||
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OK |
REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here |
NG |
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |