P2742
AB60E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: 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 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, it illuminates the warning light.
HINT:
- The temperature of 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 ATF temperature is in the normal range, it decreases to less than 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 the D position or S6 range, in 5th gear with the shift lever in the S5 range, and 4th gear with the shift lever in the S4 range.
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 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: Range Check (Chattering)
P2742: Range Check (Low Voltage)
P2743: Range Check (High Voltage)
TYPICAL MALFUNCTION THRESHOLDS
P2740: Range Check (Chattering)
P2742: Range Check (Low Voltage)
P2743: Range Check (High Voltage)
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
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.
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 the Techstream to the DLC3.
(d) Turn the ignition switch to ON.
(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 more, there is a short circuit.
- When DTC P2743 is output and the Techstream output is -40°C (-40°F), there is an open circuit.
Measure the resistance between terminal THO2 and the body ground.
PROCEDURE
1. INSPECT NO. 1 TRANSMISSION WIRE (NO. 2 ATF TEMPERATURE SENSOR)
(a) Disconnect the D41 No. 1 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 of one of the ATF temperatures shown in the table below, the driveability of the vehicle may decrease.
Standard Resistance:
NG -- REPAIR OR REPLACE NO. 1 TRANSMISSION WIRE (NO. 2 ATF TEMPERATURE SENSOR)
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (NO. 1 TRANSMISSION WIRE - ECM)
(a) Disconnect the D56 ECM connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE ECM