B2408
DTC B2408 INTAKE MOTOR FAILUREComponent Location:
GENERAL DESCRIPTION
Intake door located at heater unit controls the inlet of car. It contains intake motor that changes Intake door position and potentiometer that monitors position of intake door. When driver operates the intake switch, ECU receives mode signal from intake switch and operates intake door motor to turn intake door to intended position. (with FRE mode signal, intake door is closed and with REC mode signal, intake door is opened) in operation, potentiometer delivers intake door position transformed into voltage value to A/C ECU.
DTC DESCRIPTION
The ECM sets DTC B2408 if the intake motor doesn't move to intended position within 40 sec (The ECM attempts to move the intake door for a 2 second duration at a frequency of 3 times every 20 seconds before storing a DTC.)
DTC Detecting Condition:
Signal Waveform And Data:
Schematic Diagram:
MONITOR DTC STATUS
1. Connect scantool to Data Link Connector (DLC).
2. Warm up the engine to normal operating temperature.
3. Monitor DTC (Diagnostics Trouble Code) on the scantool.
4. Is the same DTC displayed again?
YES - Go to "Inspection/Repair" procedure.
NO - Fault is intermittent caused by poor contact in the sensors and/or A/C-ECM connector or was repaired and A/C-ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of vehicle Repair" procedure.
W/HARNESS INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repar as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Motor control circuit Open Inspection" procedure.
MOTOR CONTROL CIRCUIT OPEN INSPECTION
1. Ignition "OFF"
2. A/C-ECU, intake actuator : Disconnect.
3. Measure resistance between Motor (+) terminal of intake actuator harness connector and Motor (+) terminal of A/C-ECU harness connector.
4. Measure resistance between Motor (-) terminal of intake actuator harness connector and Motor (-) terminal of A/C-ECU harness connector.
Specification : 1 ohm below
5. Is "resistance" display near the specified value?
YES - Go to "Motor control circuit short to ground Inspection" procedure.
NO
- Check for open in harness.
- Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
MOTOR CONTROL CIRCUIT SHORT TO GROUND INSPECTION
1. Ignition "OFF"
2. A/C-ECU : Connect Driver air mix actuator : Disconnect.
3. Measure resistance between Motor (+) terminal of Driver air mix actuator harness connector and and chassis ground.
4. Measure resistance between Motor (-) terminal of Driver air mix actuator harness connector and and chassis ground.
Specification : Infinity
5. Is "resistance" display near the specified value?
YES - Go to "Component inspection" procedure.
NO
- Check for short in harness.
- Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
CHECK INTAKE ACTUATOR
1. Ignition "OFF"
2. A/C-ECU, intake actuator : Disconnect.
3. Connect (+) terminal of battery to FRE (+) of intake actuator and (-) terminal to REC (-). (Component side).
4. Verify that the actuator operates to the REC position.
5. Verify that the temperature actuator operates to the FRE position with reverse connecting.(REC (-) and FRE (+)) (Component side)
Specification: Refer the specifications in fig 1
6. Is "Door position" display near the specified value?
YES - Go to "Check potentiometer" procedure.
NO - Substitute with a known-good intake actuator and check for proper operation. If the problem is corrected, replace intake actuator and then go to "Verification of Vehicle Repair" procedure.
CHECK POTENTIOMETER
1. Ignition "OFF"
2. A/C-ECU : Connect, intake actuator : Disconnect.
3. Ignition "ON"(ENG1NE "OFF").
4. Measure voltage between Signal (F/B) terminal of intake actuator harness connector and and chassis ground. (Component side)
Specification : Refer the specifications in fig.2
Specifications : Voltage value of intake potentiometer as a function of intake door position.
5. Is "voltage" display near the specified value?
YES - 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.
NO - Substitute with a known-good Driver air mix actuator and check for proper operation. If the problem is corrected, replace Driver air mix actuator and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verifying that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Using scantool, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.