SYSTEM 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 |
---|---|---|
P0796 |
The engine revs freely when 2nd or 6th gear is commanded (2-trip detection logic). When the following is detected 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 |
P0796: Shift solenoid valve SL3/OFF malfunction Shift solenoid valve SL3/ON malfunction |
Required sensors/Components |
Shift solenoid valve SL3, Speed sensor (NT), Speed sensor (NC), Crankshaft position sensor (NE) |
Frequency of operation |
Continuous |
Duration |
OFF malfunction (A) and (B) 0.5 sec. OFF malfunction (C) and (D) 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 selected gear |
2nd |
Throttle valve opening angle |
3% or more |
TCM indicated pressure value of SL1 |
1,200 kPa |
TCM indicated pressure value of SL2 |
0 kPa |
TCM indicated pressure value of SL3 |
1,200 kPa |
TCM selected gear |
6th |
Throttle valve opening angle |
3% or more |
TCM indicated pressure value of SL1 |
0 kPa |
TCM indicated pressure value of SL2 |
1,200 kPa |
TCM indicated pressure value of SL3 |
1,200 kPa |
TCM selected gear |
2nd |
Throttle valve opening angle: |
|
(When condition "D" is not detected) |
4.5% or more at engine speed 2,000 rpm (condition varies with engine speed) |
(When condition "D" is detected) |
1.5% or more at engine speed 750 rpm (condition varies with output speed) |
ECT (engine coolant temperature) |
40°C (104°F) or more |
Throttle valve opening angle |
1.5% or more at engine speed 750 rpm (condition varies with output speed) |
TCM selected gear |
1st |
Vehicle speed |
1.2 mph (2 km/h) or more |
Engine speed - Turbine speed |
50 rpm or more |
ECT (engine coolant temperature) |
40°C (104°F) or more |
TYPICAL MALFUNCTION THRESHOLDS
Turbine speed - Output speed x 2nd gear ratio |
1,000 rpm or more |
Turbine speed - Output speed x 6th gear ratio |
1,000 rpm or more |
Input (turbine) speed/Intermediate shaft speed |
3.304 to 7.724 |
Input (turbine) speed/Intermediate shaft speed |
3.304 to 7.724 |
Input (turbine) speed/Intermediate shaft speed |
1.901 to 2.340 |
CAUTION / NOTICE / HINT
NOTICE:
Perform the universal trip to clear permanent DTCs (See page ).
PROCEDURE
1. |
CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0796) |
(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 "P0796" is output |
A |
"P0796" 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) |
D |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SL4) PERFORMANCE DTC P2808) |
E |
GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE (SLT) PERFORMANCE DTC P2714) |
|
3. |
INSPECT SHIFT SOLENOID VALVE SL3 |
(a) Remove shift solenoid valve SL3. |
|
(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 SL3 |
(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 SL3 |
|
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 |
Inspection
INSPECTION
PROCEDURE
1. INSPECT BRAKE DISC INSIDE DIAMETER
(a) Using a brake drum gauge or an equivalent tool, measure the inside
diameter of the disc.
Standard inside diameter of a new disc:
190 mm (7.48 in.)
Maximum inside diamete ...
Operation Check
OPERATION CHECK
1. CHECK WINDOW LOCK SWITCH
HINT:
Before performing the window lock switch operation check, make sure that the
window lock switch is off (the switch is not pushed in).
(a) Check that the front passenger and rear windows cannot be operat ...
Customize Parameters
CUSTOMIZE PARAMETERS
HINT:
The following items can be customized.
NOTICE:
After confirming whether the items requested by the customer are applicable
or not for customization, perform customizing operations.
Be sure to record the current se ...