P2743
A760F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: P2742,P2743: Transmission Fluid Temperature Sensor "B" Circuit Low Input
P2743 - Transmission Fluid Temperature Sensor "B" Circuit High Input
DESCRIPTION
The Automatic Transmission Fluid (ATF) temperature sensor is on the transmission, just in front of the oil cooler inlet pipeline.
If the ECM detects an abnormally high ATF temperature near this sensor, a message is displayed on the multi-information display.
HINT
- The temperature of the ATF easily rises when towing, climbing hills, in traffic, etc.
- If the ATF temperature sensor becomes short-circuited, the signal that indicates that the ATF temperature is 150°C (302°F) or higher is input into the ECM.
Vehicle conditions when the sensor is normal and when the sensor is short-circuited are indicated in the table below.
HINT
*1: When the ATF is normal, it decreases to below 135°C (275°F) within 5 minutes with the shift lever in P or N in an idling state.
*2: When ATF temperature is normal, transmission lock-up occurs in 5th or 6th gear with the shift lever in D or with the S6 range selected, in 5th gear with the S5 range selected, and in 4th gear with the S4 range selected.
MONITOR DESCRIPTION
The ATF temperature sensor converts the ATF temperature into an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature, and the ECM detects an open or short in the ATF temperature circuit. If the resistance value of the ATF temperature sensor is below 25 Ohms*1 or higher than 156 kOhms*2, the ECM interprets this as a fault in the ATF sensor or wiring. The ECM will display a message on the multi-information display and store the DTC.
HINT
- *1: 150°C (302°F) or higher is indicated regardless of the actual ATF temperature.
- *2: -40°C (-40°F) is indicated regardless of the actual ATF temperature.
- The ATF temperature can be checked on the Techstream display.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.
1. DATA LIST
HINT
Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.
NOTICE:
In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.
(a) Warm up the engine.
(b) Turn the engine switch off.
(c) Connect the Techstream to the DLC3.
(d) Turn the engine switch on (IG).
(e) Turn the Techstream on.
(f) Enter the following menus: Powertrain / Engine and ECT / Data List.
(g) According to the display on the Techstream, read the Data List.
Engine and ECT
HINT
- When DTC P2742 is output and the Techstream output is 150°C (302°F) or higher, there is a short circuit.
- When DTC P2743 is output and the Techstream output is -40°C (-40°F), there is an open circuit.
- Check the temperature displayed on the tester in order to check if a malfunction exists.
PROCEDURE
1. INSPECT TRANSMISSION WIRE (NO. 2 ATF TEMPERATURE SENSOR)
(a) Disconnect the C24 transmission wire connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
HINT
If the resistance is out of the specified range at any of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE TRANSMISSION WIRE (NO. 2 ATF TEMPERATURE SENSOR) Removal
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
(a) Disconnect the C29 and C30 ECM connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM Removal