The mode control actuator mounted on heater unit adjusts position of mode door by operating Direction Motor based on signal of A/C control unit. Pressing mode select switch makes the mode control actuator shift in order of vent? B/L ? floor ? mix.
The ECM sets DTC B2409 if the direction motor dosen’t move to intended position within 40sec(The ECM attempts to move the temp door for a 2 second duration at a frequency of 3 times every 20 seconds before storing a DTC.)
Item
Detecting Condition
Possible Cause
DTC Strategy
? Voltage check
? Poor connection of connected part
? Open circuit in harness
? Short circuit in harness
? Faulty DR Direction actuator
? Fault A/C Control Unit
Threshold value
? 0.5V<Potentiometer voltage < 4.5V
Detecting time
? 40 sec
FAIL SAFE
? Setting mode : VENT Fix at VENT position
? Setting mode : Except VENT Fix at DEF position
? Voltage value of Direction potentiometer as a function of position of mode switch.
Door position
Voltage
Error Detecting Condition
VENT
0.3±0.15V
Undervoltage : 0.08V or less
DEF
4.7±0.15V
Overvoltage : 4.9V or more