2003 LEXUS LS430 Identifying ac

OK: REPAIR OR REPLACE TRANSMISSION WIRE (See step 5 on REPLACEMENT)
DTC P2757: TORQUE CONVERTER CLUTCH PRESSURE CONTROL SOLENOID
PERFORMANCE (SHIFT SOLENOID VALVE SLU)
SYSTEM DESCRIPTION
The ECM uses the signals from the throttle position sensor, Air-flow meter, turbine (input) speed sensor, output
speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM
memory to detect a mechanical problems of the shift solenoid valve SLU, valve body and torque converter
clutch.
Fig. 173: Identifying Manual Transmission

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Fig. 174: Identifying Lock-Up Operation Pressure Graph
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Fig. 175: DTC Reference Chart

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MONITOR DESCRIPTION
Torque converter lock-up is controlled by the ECM based on turbine (input) speed sensor NT, output speed
sensor SP2, engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and gear
selection. The ECM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to
the input turbine rpm (NT). The ECM calculates the actual transmission gear by comparing input turbine rpm
(NT) to output shaft rpm (SP2). When conditions are appropriate, the ECM requests "lock-up" by applying
control volta
ge to shift solenoid SLU. When the SLU is turned on, solenoid SLU applies pressure to the lock-up

Fig. 178: Identifying Accelerator Pedal Opening Angle Diagram
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1.CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P2757)
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch to the ON position and push the hand-held tester main switch ON.
c. Select the item "DIAGNOSIS/ENHANCED OBD II/DTC INFO/CURRENT CODES".
d. Read the DTCs using the hand-held tester.
Result:
DTC OUTPUT RESULT TABLE
HINT:
If any other codes besides "P2757" are output, perform troubleshooting for those DTCs first.
B: GO TO RELEVANT DTC CHART (See DIAGNOSTIC TROUBLE CODE CHART
)
A: Go to next step
2.INSPECT SHIFT SOLENOID VALVE (SLU)
a. Remove the shift solenoid valve SLU.
b. Measure the resistance according to the value(s) in the table below.
Display (DTC output)Proceed to
Only "P2757" is outputA
"P2757" and other DTCsB

Fig. 180: Identifying Lock-Up Operation Pressure Graph
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(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of continuity
in one c
ycle, and B is the period of non-continuity, then Duty Ratio = A/(A+B) x 100(%).

Fig. 181: Identifying Duty Ratio Pattern
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Fig. 182: DTC Reference Chart

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MONITOR DESCRIPTION
When an open or short in a shift solenoid valve (SLU) circuit is detected, the ECM determines there is a
malfunction. The ECM will turn on the MIL and store this DTC.
MONITOR STRATEGY
MONITOR STRATEGY TABLE
Related DTCsP2759: Shift solenoid valve SLU/Range check
Required sensors/ComponentsShift solenoid valve SLU
Frequency of operationContinuous

1.INSPECT TRANSMISSION WIRE (SLU)
a. Disconnect the transmission wire connector from the transmission.
b. Measure the resistance according to the value(s) in the table below.
Fig. 184: Identifying Transmission Wire Terminals

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Standard:
TRANSMISSION WIRE (SLU) - RESISTANCE TABLE
c. Measure the resistance according to the value(s) in the table below.
Standard (Check for short):
Tester ConnectionSpecified Condition 20°C (68°F)
12 (SLU+) - 4 (SLU-)5.0 to 5.6 ohms

Fig. 190: Identifying Transmission Control Switch Connector Terminals
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Standard:

Fig. 192: Identifying Transmission Control Switch Connector Terminals
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Standard:
TRANSMISSION CONTROL SWITCH - BODY GROUND - RESISTANCE TABLE
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (See ELECTRONIC CIRCUIT
INSPECTION PROCEDURE )
Tester ConnectionSpecified Condition
5 - Body groundBelow 1 ohms