The automatic transmission fluid(ATF) temperature sensor is installed in the Valve Body. This sensor uses a thermistor whose resistance changes according to the temperature changes. The TCM supplies a 5V reference voltage to the sensor, and the output voltage of the sensor changes when the ATF temperature varies. The automatic transmission fluid(ATF) temperature provides very important data for the TCM’s control of the Torque Converter Clutch, and is also used for many other purposes.
This DTC code is set when the ATF temperature output voltage is lower than a value generated by thermistor resistance, in a normal operating range, for approximately 1 second or longer. The TCM regards the ATF temperature as fixed at a value of 80 °C.
Item
Detecting Condition
Possible Cause
Case 1
DTC Strategy
Rationality stuck-low
Open or short in circuit
Faulty sensor
Faulty PCM
Enable Conditions
Output Speed = 1000rpm
Engine Speed = 1000rpm
Accumulated time in above two condition 5min
TFT at start-up and ambient temp.
(<50?) and (>-7?) or TFT at start-up <30? Engine coolant temp. increase since start-up >40?
Threshold Value
Since start-up
Case 2
Rationality stuck-high
TFT at previous engine-off >50?
Engine coolant temp. at previous engine-off >73.5?
Engine coolant temp. drop from the previous engine-off >34?
Intake air temperature < 35?
Time after TCM turns on 0.5sec
TFT drop <2? from the previous engine-off
Case 3
Rationality-low
Ignition key input voltage>10V
TFT.=-10?
Diagnostic Time
1 event
Fail Safe
Learning control and Intelligent shift are inhibited.
Fluid temperature is regarded as 80?
Temperature ?(?)
Resistance (?)
Resistance (k?)
-40
139.5
80
1.08
-20
47.7
100
0.63
0
18.6
120
0.38
20
8.1
140
0.25
40
3.8
160
0.16
60
1.98