P2740
A750E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM (for 1GR-FE): P2740: Transmission Fluid Temperature Sensor "B" Circuit
DTC P2740 - Transmission Fluid Temperature Sensor "B" Circuit
DTC P2742 - Transmission Fluid Temperature Sensor "B" Circuit Low Input
DTC P2743 - Transmission Fluid Temperature Sensor "B" Circuit High Input
DESCRIPTION
The No. 2 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, it illuminates the warning light.
HINT:
- The temperature of ATF easily rises when towing, climbing hills, in traffic, etc.
- If the No. 2 ATF temperature sensor becomes short-circuited, the signal that indicates 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 ATF temperature is normal, transmission lock-up occurs in 5th gear with the shift lever in the D position, and 4th gear with the shift lever in the 4 position.
*2: When ATF temperature is in the normal range, it decreases to less than 135°C (275°F) within 5 minutes with the shift lever in the P or N position in an idling state.
MONITOR DESCRIPTION
ATF temperature sensor converts 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 is less than 25 Ohms*1 or more than 156 kOhms*2, the ECM interprets this as a fault in the ATF sensor or wiring. The ECM will illuminate the MIL and store the DTC.
HINT:
- *1: 150°C (302°F) or more 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.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All
P2740, P2742: Range check (Fluttering, Low voltage)
P2743: Range check (High voltage)
TYPICAL MALFUNCTION THRESHOLDS
P2740: Range check (Fluttering)
P2742: Range check (Low voltage)
P2743: Range check (High voltage)
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
1. DATA LIST
HINT: According to the Data List displayed by Techstream, you can read the values of switches, sensors, actuators and so on without removing parts. Reading the Data List as the first step of troubleshooting is one method to save time.
NOTE: 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 ignition switch OFF.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch ON, and turn the tester main switch ON.
(e) Enter the following menus: Powertrain / Engine and ECT / Data List.
(f) According to the display on tester, read the "Data List".
Engine and ECT
HINT:
- When DTC P2742 is output and Techstream output is 150°C (302°F) or more, there is a short circuit.
- When DTC P2743 is output and 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 transmission wire connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
HINT: If the resistance is outside the specified range at either of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.
Standard resistance:
NG -- REPAIR OR REPLACE TRANSMISSION WIRE
OK -- Continue to next step.
2. CHECK WIRE HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)
(a) Connect the transmission wire connector to the transmission.
(b) Disconnect the ECM connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for short):
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM