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 shift solenoid valve SLU, valve body and torque converter clutch mechanical problems.

DTC Code	DTC Detection Condition	Trouble Area
P2757	Either condition is met (2-trip detection logic): Both conditions are met: Lock-up does not occur when requested. No. 3 ATF pressure switch is off. Both conditions are met: No. 3 ATF pressure switch is on when lock-up does not occur. Lock-up occurs when shift solenoid valve SLU is commanded to turn on in the lock-up range.	Shift solenoid valve SLU remains open or closed Valve body is blocked Torque converter clutch Automatic transaxle (clutch, brake, gear, etc.) Line pressure is too low

DTC Code

DTC Detection Condition

Trouble Area

P2757

Either condition is met (2-trip detection logic):

Both conditions are met:

Lock-up does not occur when requested.
No. 3 ATF pressure switch is off.

Both conditions are met:

No. 3 ATF pressure switch is on when lock-up does not occur.
Lock-up occurs when shift solenoid valve SLU is commanded to turn on in the lock-up range.

Shift solenoid valve SLU remains open or closed
Valve body is blocked
Torque converter clutch
Automatic transaxle (clutch, brake, gear, etc.)
Line pressure is too low

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 input turbine speed (NT) to 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 clutch.

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.)

INSPECTION PROCEDURE

Refer to DTC P0741 Click here.

PROCEDURE

CHECK DTC OUTPUT (IN ADDITION TO DTC P2757)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / DTC.

Read the DTCs using the intelligent tester.

Result
Result	Proceed to
Only P2757 is output	A
P2757 and other DTCs are output	B

Tech Tips

If any other codes besides P2757 are output, perform troubleshooting for those DTCs first.

B

GO TO DTC CHART Click here

A

INSPECT SHIFT SOLENOID VALVE SLU

Text in Illustration

*a
Component without harness connected

(Shift Solenoid Valve SLU)

Remove shift solenoid valve SLU.

Text in Illustration
*a	Component without harness connected (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

NG

REPLACE SHIFT SOLENOID VALVE SLU Click here

OK

INSPECT TRANSMISSION VALVE BODY ASSEMBLY
1. Check the transmission valve body assembly Click here.
  
  OK
  
  There are no foreign objects on any valve.
NG
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here

OK
INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY
1. Check the torque converter clutch assembly Click here.
  
  OK
  
  The torque converter clutch operates normally.
NG
REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY Click here

OK

REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here

AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P2757