AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P2757
| DTC Code | DTC Name |
|---|---|
| P2757 | Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU) |
DESCRIPTION
The TCM uses the signals from the throttle position sensor, air flow meter, input turbine speed sensor, output speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
The TCM compares the engagement condition of the lock-up clutch with the lock-up schedule in the TCM memory to detect mechanical problems of the shift solenoid valve (SLU), valve body and torque converter.
DTC No. |
Detection Item |
DTC Detection Condition |
Trouble Area |
MIL |
Memory |
|---|---|---|---|---|---|
P2757 |
Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU) |
Either condition is met (2-trip detection logic):
|
|
Comes on |
DTC stored |
MONITOR DESCRIPTION
Torque converter lock-up is controlled by the TCM based on the input turbine speed sensor (speed sensor NT), output speed sensor (speed sensor NC), engine speed, engine load, engine temperature, vehicle speed, ATF temperature and gear selection. The TCM determines the lock-up status of the torque converter by comparing the engine speed (NE) to the input turbine speed (NT). The TCM calculates the actual transmission gear by comparing the input turbine speed (NT) to the output shaft speed (NC). When conditions are appropriate, the TCM requests "lock-up" by applying control voltage to shift solenoid valve SLU. When shift solenoid valve SLU is turned on, it applies pressure to the lock-up relay valve and locks the torque converter.
If the TCM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the TCM interprets this as a fault in shift solenoid valve SLU or lock-up system performance.
The TCM will turn on the MIL and store the DTC.
Example:
When any of the following is met, the system judges it to be a malfunction.
There is a difference in rotation speed between the input side (engine speed) and output side (input turbine speed) of the torque converter when the TCM commands lock-up.
(Engine speed is at least 70 rpm more than input turbine speed.)
There is no difference in rotation speed between the input side (engine speed) and output side (input turbine speed) of the torque converter when the TCM commands lock-up off.
(The difference between engine speed and input turbine speed is less than 20 rpm.)
CAUTION / NOTICE / HINT
Perform registration and/or initialization when parts related to the automatic transaxle are replaced.
ACTIVE TEST
Tip:Using the GTS to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.
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 / ECT / Active Test.
According to the display on the GTS, perform the Active Test.
Powertrain > ECT > Active Test
Tester Display
Measurement Item
Control Range
Diagnostic Note
Activate the Lock Up
Control shift solenoid valve SLU and SL to set the automatic transaxle to lock-up
ON or OFF
Can be used to check shift solenoid valve SLU and SL operation.
[Vehicle Condition]
Vehicle speed: 60 km/h (37 mph) or more
Powertrain > ECT > Active Test
Tester Display
Activate the Lock Up
Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.
Tip:When changing the accelerator pedal opening angle while driving, if the engine speed does not change abruptly, lock-up is on.
When decelerating, slowly release the accelerator pedal, but do not fully release it (fully releasing the pedal will close the throttle valve and lock-up may be turned off).
PROCEDURE
CHECK DTC OUTPUT (IN ADDITION TO DTC P2757)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Powertrain / ECT / Trouble Codes.
Powertrain > ECT > Trouble Codes
Read the DTCs using the GTS.
Result
Result
Proceed to
Only P2757 is output
A
P2757 and other DTCs are output
B
Tip:If any other codes besides P2757 are output, perform troubleshooting for those DTCs first.
INSPECT SHIFT SOLENOID VALVE SLU
-
*1
Shift Solenoid Valve SLU
Remove shift solenoid valve SLU.
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
Result
Proceed to
OK
NG
-
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly.
OK
There are no foreign objects on any valve.
Result
Proceed to
OK
NG
INSPECT TORQUE CONVERTER ASSEMBLY
Check the torque converter assembly.
OK
The torque converter operates normally.
Result
Proceed to
OK
NG