3.
Monitor the "Intake Potentiometer" Parameter on the Scantool while operating Intake switch.
Intake door located at heater unit controls the inlet of car. When driver operates the intake switch, A/C controller recirculationeives mode signal from intake switch and operates intake door actuator to turn intake door to intended position. (with fresh mode signal, intake door is closed and with fresh mode signal, intake door is opened.
The A/C controller sets DTC B2408 if the intake motor Doesn't move to intended position within 40sec(The A/C controller attempts to move the intake door for a 2 second duration at a freshquency 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 Intake potentiometer |
Threshold value | ● ＜ 0.1V | |
Detecting time | ● 0.3 sec | |
FAIL SAFE | - |
※ Voltage value of Intake potentiometer as a function of position of Intake door
Door position | Voltage | Threshold value |
Fresh | 0.3±0.15V | Voltage value 0.08V or less |
Recirculation | 4.7±0.15V | Voltage value 4.9V or more |
Connect scantool to Data Link Connector(DLC).
Engine "ON"
Monitor the "Intake Potentiometer" Parameter on the Scantool while operating Intake switch.
Are the DTC B2408 present and is parameter of "Intake Potentiometer" fixed?
※ There is any fault in Intake potentiometer. If the parameter of "Intake potentiometer" is 30% or less when the actuator operates to the fresh position, or If the parameter is 60% and more when the actuator operates to the recirculation position.
Go to "Inspection" procedure.
Fault is intermittent caused by poor contact in the sensor's and/or A/C controller's connector or was repaired and A/C controller memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
Many malfunctions in the electrical system are caused by poor harness and terminals.
Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Go to "Signal circuit inspection" procedure.
Check for open in harness.
Ignition "OFF"
Disconnect Intake potentiometer.
Measure resistance between terminal "3,4" of Intake potentiometer and terminal "22,23" of A/C control unit.
Specification : Approx. 0 Ω
Is the measured resistance within specifications?
Go to "Check for short to ground in harness" procedure.
Check for open in signal harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for short to ground in harness.
Ignition "OFF"
Disconnect Driver Air Mix Actuator.
Measure resistance between terminal "3,4" of Driver Air Mix Motor and chassis ground.
Specification : Approx. ∞ Ω
Is the measured resistance within specifications?
Go to "Visual/Physical Inspection " procedure.
Check for short to ground in signal harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check actuator.
※ Check if Driver Air Mix Actuator works properly through ACTUATION TEST.
Ignition : ON
Connect Scantool and select " ACTUATION TEST" mode and press [F1]
Does Intake Actuator work properly?
Go to "Component Inspection" procedure.
Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
Check actuator motor.
Ignition "OFF"
Disconnect Intake Potentiometer.
Verify that the temperature actuator operates to the fresh position when connecting 12V to the terminal "3" and grounding terminal "4".
Verify that the temperature actuator operates to the recirculation position when the connections are reversed.
Does the actuator work properly?
Go to "Check potentiometer" procedure.
Substitute with a known-good actuator and check for proper operation. If the problem is corrected, replace actuator and then go to "Verification of Vehicle Repair" procedure.
Check potentiometer
Ignition "ON"
Connect Intake potentiometer.
Measure voltage between terminal "5" and "6" of Intake potentiometer while operating Intake switch.
Specification : Refer the specifications
Door position | Voltage (5-6) | Error detecting |
Fresh | 0.3 ± 0.15V | Low voltage : 0.08V or less |
Recirculation | 4.7 ± 0.15V | High voltage : 4.9V or more |
Specifications : Voltage value of Intake potentiometer as a function of position of Intake.
Is the measured voltage within specifications?
Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
Substitute with a known-good actuator and check for proper operation. If the problem is corrected, replace actuator and then go to "Verification of Vehicle Repair" procedure.
Check A/C Control Unit.
Engine "ON"
Connect A/C Control Unit.
Measure voltage between terminal "22" and "23" of A/C Control Unit while operating the Intake switch.
Specification :Approx. 12V
Is the measured voltage within specifications?
Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
Substitute with a known-good A/C Control Unit and check for proper operation.
If the problem is corrected, replace A/C Control Unit and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode and then clear DTC.
Operate the vehicle and monitor the DTC on the scantool.
Are any DTCs present?
Go to the applicable troubleshooting procedure.
System is performing to specification at this time.
