Coolant temperature is detected by a water temperature sensor located at the heater unit. The A/C ECU uses coolant temperature to control the cold engine lockout function. The cold engine lockout function reduces blower speed until coolant temperature reaches the threshold value.
Air conditioner Control Module sets DTC B1202 if water temperature sensor has been detected over 4.9V for 4 seconds.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Voltage check |
•
Poor connection in wireharness
•
Open in signal circuit
•
Short to battery in signal circuit
•
Faulty Water temperature sensor
•
Faulty Air conditioner Control Module |
Enable Conditions |
•
IG KEY ON | |
Threshold value |
•
Water temperature sensor has been detected over 4.9V for 4 seconds. | |
Failsafe |
•
Control with the value of 85℃(185℉). |
Temperature(℃/℉) | Resistance(㏀) | Temperature(℃/℉) | Resistance(㏀) |
-10/14 | 55.8 | 40/104 | 5.3 |
0/32 | 32.9 | 60/140 | 2.4 |
20/68 | 12.5 | 80/176 | 1.2 |
