Toyota Tacoma (2015-2018) Service Manual: Transmission Fluid Temperature Sensor "B" Circuit Low Input (P2742,P2743)
DESCRIPTION
The No. 2 ATF temperature sensor is installed in the transmission valve body assembly.
If the ECM detects an abnormally high ATF temperature near this sensor, it illuminates the warning indicator.
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 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.
|
No. 2 ATF Temperature Sensor State |
Detection Condition |
Symptom |
Recovery Condition |
|---|---|---|---|
|
Sensor is normal |
ATF temperature higher than 150°C (302°F) |
ATF temperature warning indicator remains on |
ATF temperature below 135°C (275°F)*1 |
|
ATF temperature higher than 130°C (266°F) |
Shift point too high |
ATF temperature below 110°C (230°F) |
|
|
Sensor is short-circuited |
Any conditions |
Shift point too high |
Symptoms still occur |
|
Engine coolant temperature higher than 95°C (203°F) |
Lock-up at 3rd gear*2 |
Symptoms still occur |
HINT:
*1: When ATF temperature is in the normal range, 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 4th, 5th and 6th gear with the shift lever in D or with the S6 range selected, in 4th or 5th gear with the S5 range selected, and 4th gear with the S4 range selected.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
P2742 |
No. 2 ATF temperature sensor resistance is below 25 Ω for 0.5 seconds or more (1 trip detection logic). |
|
|
P2743 |
No. 2 ATF temperature sensor resistance is higher than 156 kΩ for 0.5 seconds or more and either condition is met (1 trip detection logic): (A) 15 minutes or more have elapsed after the engine start when the engine coolant temperature or intake air temperature is -29.375°C (-20.875°F) or less. (B) 10 seconds or more have elapsed after the engine start when the engine coolant temperature and intake air temperature are higher than -29.375°C (-20.875°F). |
|
MONITOR DESCRIPTION
The No. 2 ATF temperature sensor converts the ATF temperature to an electrical resistance value. Based on the resistance, the ECM determines the ATF temperature and detects an open or short in the No. 2 ATF temperature sensor circuit. If the resistance value of the No. 2 ATF temperature sensor is below 25 Ω*1 or higher than 156 kΩ*2, the ECM interprets this as a fault in the No. 2 ATF temperature sensor or wiring. The ECM stores the DTC.
*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.
HINT:
The ATF temperature can be checked on the Techstream display.
WIRING DIAGRAM
Refer to DTC P0712 (See page .gif)
).
CAUTION / NOTICE / HINT
NOTICE:
- Perform the universal trip to clear permanent DTCs (See page
).
- Perform registration and/or initialization when parts related to the
automatic transmission are replaced (See page
).
HINT:
After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.
- Start the engine and wait for 15 minutes or more.
- Check for DTCs again (See page ).
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 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|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
A/T Oil Temperature 2 |
No. 2 ATF temperature sensor value/ Min.: -40°C (-40°F) Max.: 150°C (302°F) |
|
If the value -40°C (-40°F) or 150°C (302°F), No. 2 ATF temperature sensor circuit is open or shorted. |
HINT:
- When DTC P2742 is output and the Techstream indicates 150°C (302°F) or higher, there is a short circuit.
- When DTC P2743 is output and the Techstream indicates -40°C (-40°F),
there is an open circuit.
Check the temperature displayed on the Techstream in order to check if a malfunction exists.
|
Temperature Displayed |
Malfunction |
|---|---|
|
-40°C (-40°F) |
Open circuit |
|
150°C (302°F) or higher |
Short circuit |
PROCEDURE
|
1. |
INSPECT NO. 2 ATF TEMPERATURE SENSOR (TRANSMISSION WIRE) |
|
(a) Disconnect the E1 transmission wire connector. |
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
5 (OT2+) - 6 (OT2-) |
Always |
25 Ω to 156 kΩ |
|
5 (OT2+) - Body ground |
Always |
10 kΩ or higher |
|
6 (OT2-) - Body ground |
Always |
10 kΩ or higher |
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.
|
ATF Temperature |
Specified Condition |
|
10°C (50°F) |
5 to 8 kΩ |
|
25°C (77°F) |
2.5 to 4.5 kΩ |
|
110°C (230°F) |
0.22 to 0.28 kΩ |
|
*a |
Component without harness connected (Transmission Wire) |
| NG | .gif) |
REPLACE NO. 2 ATF TEMPERATURE SENSOR (TRANSMISSION WIRE) |
|
.gif)
|
2. |
CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM) |
|
(a) Disconnect the ECM connector. |
|
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
E19-22 (THO2) - E19-21 (ETHO) |
Always |
25 Ω to 156 kΩ |
|
E19-22 (THO2) - Body ground |
Always |
10 kΩ or higher |
|
E19-21 (ETHO) - Body ground |
Always |
10 kΩ or higher |
|
*a |
Rear view of wire harness connector (to ECM) |
| OK | |
REPLACE ECM |
| NG | |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT) (P2716)
DESCRIPTION
Refer to the system description for DTC P2714 (See page
).
DTC No.
DTC Detection Condition
Trouble Area
P2716
Open or short ...
Short in Torque Converter Clutch Solenoid Circuit (Shift Solenoid Valve SL)
(P2769,P2770)
DESCRIPTION
Shift solenoid valve SL is turned on and off by signals from the ECM to control
the hydraulic pressure acting on the lock-up relay valve, which then controls operation
of the lock-up ...
Other materials:
Components
COMPONENTS
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
ILLUSTRATION
...
Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART
HINT:
If a trouble code is displayed during the DTC check, inspect the trouble areas
listed for that code. For details of the code, refer to the "See page" below.
Lighting system
DTC Code
Detection Item
See page
...
Using the radio
Select “AM” or “FM” on the “Select Audio Source” screen to begin listening
to the radio.
Audio control screen
“Select Audio Source” screen
appears
Preset stations
Select to display RBDS text
message
Scanning for receivable station
Sele ...
