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 No. |
DTC Detection Condition |
Trouble Area |
---|---|---|
P2808 |
The engine revs freely when 3rd or 5th gear is commanded. (2-trip detection logic) When any of the following is detected. In addition, the condition that 4th gear is engaged when 4th gear is commanded occurs twice. (2-trip detection logic)
|
|
MONITOR DESCRIPTION
The TCM commands gear shifts by turning the shift solenoid valves on and off. According to the input shaft revolution (speed), intermediate (counter) shaft revolution (speed) and output shaft revolution (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.
MONITOR STRATEGY
Related DTCs |
P2808: Shift solenoid valve SL4/OFF malfunction Shift solenoid valve SL4/ON malfunction |
Required sensors/Components |
Shift solenoid valve SL4, Speed sensor (NT), Speed sensor (NC), Crankshaft position sensor (NE) |
Frequency of operation |
Continuous |
Duration |
OFF malfunction (A): 0.5 sec. OFF malfunction (B): 0.8 sec. ON malfunction: 0.8 sec. |
MIL operation |
2 driving cycles |
Sequence of operation |
None |
TYPICAL ENABLING CONDITIONS
ALL:
The monitor will run whenever this DTC is not present. (Not circuit malfunction) |
P0712, P0713 (ATF temperature sensor circuit (TFT sensor)) P0115, P0117, P0118 (ECT sensor circuit) P0715, P0717 (Turbine speed sensor circuit) P0791, P0793 (Intermediate shaft speed sensor circuit) P0748 (Shift solenoid valve SL1 circuit) P0778 (Shift solenoid valve SL2 circuit) P0798 (Shift solenoid valve SL3 circuit) P2810 (Shift solenoid valve SL4 circuit) P0327, P0328, P0332, P0333 (KCS sensor circuit) P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P0657, P1607, P2102, P2103, P2111, P2112, P2118, P2119, P2135 ((ETCS) Electronic throttle control system) U0100 (CAN communication system) |
Transmission range |
"D" |
TFT (Transmission fluid temperature) |
-10°C (14°F) or more |
TFT (Transmission fluid temperature) sensor circuit |
No circuit malfunction |
ECT (Engine coolant temperature) sensor circuit |
No circuit malfunction |
Turbine speed sensor circuit |
No circuit malfunction |
Intermediate shaft speed sensor circuit |
No circuit malfunction |
Shift solenoid valve SL1 circuit |
No circuit malfunction |
Shift solenoid valve SL2 circuit |
No circuit malfunction |
Shift solenoid valve SL3 circuit |
No circuit malfunction |
Shift solenoid valve SL4 circuit |
No circuit malfunction |
(KCS) Knock control sensor circuit |
No circuit malfunction |
(ETCS) Electronic throttle control system |
Not system down |
CAN communication system |
Not system down |
Engine |
Starting |
TCM select gear |
3rd or 5th |
Throttle valve opening angle |
3% or more |
TCM select gear |
3rd |
Throttle valve opening angle |
4.5% or more |
Vehicle speed |
1.2 mph (2 km/h) or more |
ECT (Engine coolant temperature) |
40°C (104°F) or more |
Turbine speed/Output speed (NT/NO) with 1st |
3.304 to 7.724 |
Turbine speed/Output speed (NT/NO) with 2nd |
1.901 to 2.340 |
Turbine speed/Output speed (NT/NO) with 3rd |
1.399 to 1.649 |
Turbine speed/Output speed (NT/NO) with 4th |
0.998 to 1.138 |
Turbine speed/Output speed (NT/NO) with 5th |
0.705 to 0.836 |
Turbine speed/Output speed (NT/NO) with 6th |
0.568 to 0.695 |
TCM select gear |
1st |
Time after transmission to 1st gear |
0.1 sec. or more |
Vehicle speed |
1.2 mph (2 km/h) to 24.9 mph (40 km/h) |
ECT (Engine coolant temperature) |
40°C (104°F) or more |
Turbine speed/Output speed (NT/NO) with 1st |
3.304 to 7.724 |
Turbine speed/Output speed (NT/NO) with 2nd |
1.901 to 2.340 |
Turbine speed/Output speed (NT/NO) with 3rd |
1.399 to 1.649 |
Turbine speed/Output speed (NT/NO) with 4th |
0.998 to 1.138 |
Turbine speed/Output speed (NT/NO) with 5th |
0.705 to 0.836 |
Turbine speed/Output speed (NT/NO) with 6th |
0.568 to 0.695 |
TCM select gear |
2nd |
Throttle valve opening angle |
4.5% or more at engine speed 2,000 rpm (condition varies with engine speed) |
Vehicle speed |
1.2 mph (2 km/h) or more |
ECT (Engine coolant temperature) |
40°C (104°F) or more |
Turbine speed/Output speed (NT/NO) with 1st |
3.304 to 7.724 |
Turbine speed/Output speed (NT/NO) with 2nd |
1.901 to 2.340 |
Turbine speed/Output speed (NT/NO) with 3rd |
1.399 to 1.649 |
Turbine speed/Output speed (NT/NO) with 4th |
0.998 to 1.138 |
Turbine speed/Output speed (NT/NO) with 5th |
0.705 to 0.836 |
Turbine speed/Output speed (NT/NO) with 6th |
0.568 to 0.695 |
TCM select gear |
6th |
Throttle valve opening angle |
4.5% or more at engine speed 2,000 rpm (condition varies with engine speed) |
Vehicle speed |
1.2 mph (2 km/h) or more |
ECT (Engine coolant temperature) |
40°C (104°F) or more |
Turbine speed/Output speed (NT/NO) with 1st |
3.304 to 7.724 |
Turbine speed/Output speed (NT/NO) with 2nd |
1.901 to 2.340 |
Turbine speed/Output speed (NT/NO) with 3rd |
1.399 to 1.649 |
Turbine speed/Output speed (NT/NO) with 4th |
0.998 to 1.138 |
Turbine speed/Output speed (NT/NO) with 5th |
0.705 to 0.836 |
Turbine speed/Output speed (NT/NO) with 6th |
0.568 to 0.695 |
TCM select gear |
4th |
Throttle valve opening angle |
4.5% or more at engine speed 2,000 rpm (condition vary with engine speed) |
Vehicle speed |
1.2 mph (2 km/h) or more |
ECT (Engine coolant temperature) |
40°C (104°F) or more |
Turbine speed/Output speed (NT/NO) with 1st |
3.304 to 7.724 |
Turbine speed/Output speed (NT/NO) with 2nd |
1.901 to 2.340 |
Turbine speed/Output speed (NT/NO) with 3rd |
1.399 to 1.649 |
Turbine speed/Output speed (NT/NO) with 4th |
0.998 to 1.138 |
Turbine speed/Output speed (NT/NO) with 5th |
0.705 to 0.836 |
Turbine speed/Output speed (NT/NO) with 6th |
0.568 to 0.695 |
TYPICAL MALFUNCTION THRESHOLDS
OFF malfunction (A):
Turbine speed - Output speed x Gear ratio |
1,000 rpm or more |
Turbine speed / Output speed |
3.304 to 7.724 |
Turbine speed / Output speed |
1.399 to 1.649 |
Turbine speed / Output speed |
0.705 to 0.836 |
Turbine speed / Output speed |
0.998 to 1.138 |
CAUTION / NOTICE / HINT
NOTICE:
Perform the universal trip to clear permanent DTCs (See page ).
PROCEDURE
1. |
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2808) |
(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 / ECT / Trouble Codes.
(e) Read the DTCs using the Techstream.
Display (DTC output) |
Proceed to |
---|---|
Only "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.
A |
GO TO STEP 3 |
|
2. |
PERFORM ACTIVE TEST USING TECHSTREAM |
NOTICE:
This test should always be performed with at least 2 people.
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / ECT / Active Test.
(g) According to the display on the Techstream, perform the Active Test.
HINT:
Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem (See page ).
Item |
Test Details |
Diagnostic Note |
---|---|---|
Control the Shift Position |
[Test Details] Operates the shift solenoid valves to allow gears to selected manually. [Others]
|
Can be used to check the operation of the shift solenoid valves. |
NOTICE:
HINT:
The gear commanded by the TCM is shown in the Data List / Shift Status display on the Techstream.
(h) Check the vehicle speed and the gear when the engine speed is 1000 rpm.
HINT:
Because the torque converter 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.
Standard:
1st |
2nd |
3rd |
4th |
5th |
6th |
---|---|---|---|---|---|
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) |
(i) Compare the TCM commanded gear and the actual gear.
Actuator Gear during Malfunction |
TCM Commanded Gear |
Proceed to |
||||||
---|---|---|---|---|---|---|---|---|
1st |
2nd |
3rd |
4th |
5th |
6th |
|||
Shift solenoid SL1 |
Stuck ON |
1st |
2nd |
3rd |
4th |
4th |
4th |
A |
Stuck OFF |
N*1 |
N*1 |
N*1 |
N*1 |
5th |
6th |
||
Shift solenoid SL2 |
Stuck ON |
4th |
4th |
4th |
4th |
5th |
6th |
B |
Stuck OFF |
1st |
2nd |
3rd |
1st |
N*1 |
N*1 |
||
Shift solenoid SL3 |
Stuck ON |
2nd |
2nd |
3rd |
4th |
5th |
6th |
C |
Stuck OFF |
1st |
1st |
3rd |
4th |
5th |
N*1 |
||
Shift solenoid SL4 |
Stuck ON*3 |
3rd |
3rd |
3rd |
4th |
5th |
5th |
D |
Stuck OFF |
1st |
2nd |
1st |
4th |
N*1 |
6th |
||
Shift solenoid 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:
A |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL1) PERFORMANCE DTC P0746) |
B |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL2) PERFORMANCE DTC P0776) |
C |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL3) PERFORMANCE DTC P0796) |
E |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SLT) PERFORMANCE DTC P2714) |
|
3. |
INSPECT SHIFT SOLENOID VALVE SL4 |
(a) Remove shift solenoid valve SL4. |
|
(b) 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 |
*1 |
Shift Solenoid Valve SL4 |
(c) Connect a battery positive (+) lead with a 21 W bulb to terminal 2 and a negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.
OK:
Valve moves and makes an operating sound.
NG |
REPLACE SHIFT SOLENOID VALVE SL4 |
|
4. |
INSPECT TRANSMISSION VALVE BODY ASSEMBLY |
(a) Check the transmission valve body assembly (See page ).
OK:
There are no foreign objects on each valve and they operate smoothly.
OK |
REPLACE AUTOMATIC TRANSAXLE ASSEMBLY |
NG |
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY |
Installation
INSTALLATION
PROCEDURE
1. INSTALL TRANSMISSION CONTROL CABLE ASSEMBLY
NOTICE:
Before installing the transmission control cable assembly, check that the park/neutral
position switch and the shift lever are in neutral.
(a) Pass the control cable from the ...
Installing the spare tire
Remove any dirt or foreign matter from the wheel contact surface.
If foreign matter is on the wheel contact surface, the wheel nuts may loosen
while the vehicle is in motion, and the tire may come off the vehicle.
Install the spare tire and loosely tig ...
Transfer Case Front Oil Seal(when Using The Engine Support Bridge)
Components
COMPONENTS
ILLUSTRATION
Replacement
REPLACEMENT
PROCEDURE
1. REMOVE TRANSFER ASSEMBLY
See page
2. REMOVE TRANSFER CASE FRONT OIL SEAL
(a) Using SST, remove the transfer case front oil seal from the transfer
case.
S ...