Dtc P2808 Pressure Control Solenoid G Performance (Shift Solenoid Valve Sl4)
SYSTEM DESCRIPTION
MONITOR DESCRIPTION
INSPECTION PROCEDURE
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2808)
PERFORM ACTIVE TEST USING GTS (CONTROL THE SHIFT POSITION)
INSPECT SHIFT SOLENOID VALVE SL4
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
DTC P2808 Pressure Control Solenoid "G" Performance (Shift Solenoid Valve SL4) |
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.
| DTC Detection Condition
| Trouble Area
|
P2808
| Either condition is met (2 trip detection logic):
- The engine revs freely when a shift to 3rd or 5th gear is commanded.
- The condition that 4th gear is engaged when a shift to 4th gear is commanded occurs twice, and one of the following conditions is met:
- When a shift to 1st gear is commanded, 3rd gear is engaged.
- When a shift to 2nd gear is commanded, 3rd gear is engaged.
- When a shift to 6th gear is commanded, 5th gear is engaged.
| - Shift solenoid valve SL4 remains open or closed
- Transmission valve body assembly is blocked
- Automatic transmission assembly (clutch, brake or gear etc.)
|
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.
INSPECTION PROCEDURE
- NOTICE:
- Perform registration and/or initialization when parts related to the automatic transmission are replaced (LandCruiser RM000000O7H0HRX.html).
- HINT:
- 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 (LandCruiser RM000000W790SFX.html).*1
- Turn the engine switch off.
- Perform step (*1) again.
- Check for DTCs again (LandCruiser RM000000W7711JX.html).
1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2808) |
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Turn the GTS on.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Read the DTCs using the GTS.
ResultResult
| Proceed to
|
Only DTC P2808 is output
| A
|
P2808 and other DTCs are output
| B
|
- HINT:
- If a solenoid is stuck off, DTCs for several solenoids including the malfunctioning solenoid will be detected.
2.PERFORM ACTIVE TEST USING GTS (CONTROL THE SHIFT POSITION) |
- NOTICE:
- This test should always be performed with at least 2 people.
Warm up the engine.
Turn the engine switch off.
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
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.
- HINT:
- Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem (LandCruiser RM000000O8L0SWX.html).
Engine and ECTTester Display
| Test Part
| Control Range
| Diagnostic Note
|
Control the Shift Position
| Operates the shift solenoid valves to allow gears to be selected manually.
| - Press "→" button: Up-shift occurs
- Press "←" button: Down-shift occurs
| 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]
- 50 km/h (31 mph) or less
|
- HINT:
- 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:
Actual Gear during Malfunction
| ECM Commanded Gear
| Proceed to
|
1st
| 2nd
| 3rd
| 4th
| 5th
| 6th
|
Shift solenoid valve SL1
| Stuck ON
| 1st
| 2nd
| 3rd
| 4th
| 4th
| 4th
| A
|
Stuck OFF
| N*1
| N*1
| N*1
| N*1
| 5th
| 6th
|
Shift solenoid valve SL2
| Stuck ON
| 4th
| 4th
| 4th
| 4th
| 5th
| 6th
| B
|
Stuck OFF
| 1st
| 2nd
| 3rd
| 1st
| N*1
| N*1
|
Shift solenoid valve SL3
| Stuck ON
| 2nd
| 2nd
| 3rd
| 4th
| 5th
| 6th
| C
|
Stuck OFF
| 1st
| 1st
| 3rd
| 4th
| 5th
| N*1
|
Shift solenoid valve SL4
| Stuck ON
| 3rd
| 3rd
| 3rd
| 4th
| 5th
| 5th
| D
|
Stuck OFF
| 1st
| 2nd
| 1st
| 4th
| N*1
| 6th
|
Shift solenoid valve SLT
| Stuck ON
| N*2
| N*2
| N*2
| N*2
| N*2
| N*2
| E
|
Stuck OFF*3
| 1st
| 2nd
| 3rd
| 4th
| 5th
| 6th
|
- HINT:
- *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.
3.INSPECT SHIFT SOLENOID VALVE SL4 |
Remove shift solenoid valve SL4 (LandCruiser RM000000O9L07IX.html).
Measure the resistance according to the value(s) in the table below.
- Standard Resistance:
Tester Connection
| Condition
| Specified Condition
|
1 - 2
| 20°C (68°F)
| 5.0 to 5.6 Ω
|
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
- OK:
Measurement Condition
| Specified Condition
|
- Battery positive (+) with a 21 W bulb → Terminal 1
- Battery negative (-) → Terminal 2
| Valve moves and makes an operating noise
|
Text in Illustration*1
| Shift Solenoid Valve SL4
|
4.INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
Check the transmission valve body assembly (LandCruiser RM000000O9L07IX.html).
- OK:
- There is no foreign matter on each valve and they operate smoothly.