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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, a message is displayed on the multi-information display.

HINT: 

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) Message is displayed on multi-information display 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)
When conditions (a) and (b) are satisfied.
(a) ATF temperature higher than 130°C (266°F)
(b) Engine coolant temperature higher than 95°C (203°F)
Lock-up in 3rd gear*2 ATF temperature below 110°C (230°F)*1 and engine coolant temperature higher than 95°C (203°F)
Sensor is short-circuited Any conditions
  • Message is displayed on multi-information display
  • Shift point too high
Symptoms persist
Engine coolant temperature higher than 95°C (203°F) Lock-up in 3rd gear*2 Symptoms persist

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.

DTC Code DTC Detection Condition Trouble Area
P2742 No. 2 ATF temperature sensor resistance is below 25 Ω (0.046 V) for 0.5 seconds or more (1-trip detection logic).
  • Short in No. 2 ATF temperature sensor circuit
  • Transmission wire (No. 2 ATF temperature sensor)
  • ECM
P2743 One of the following conditions is met (1-trip detection logic):
(A) 15 min. 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, and the ATF temperature sensor resistance is higher than 156 kΩ (4.915 V) for 0.5 sec. or more.
(B) 10 sec. 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), and the ATF temperature sensor resistance is higher than 156 kΩ (4.915 V) for 0.5 sec. or more.
  • Open in No. 2 ATF temperature sensor circuit
  • Transmission wire (No. 2 ATF temperature sensor)
  • ECM