B1208
DTC B1208 INTAKE POTENTIOMETER OPENComponent Location:
COMPONENT LOCATION
GENERAL DESCRIPTION
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).
DTC DESCRIPTION
The A/C controller sets DTC B1208 if there is an open circuit or poor connection in the intake potentiometer.
DTC Detecting Condition:
DTC DETECTING CONDITION
Specification:
SPECIFICATION
MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector (DLC).
2. Engine "ON"
3. Monitor the "Intake Potentiometer" Parameter on the Scantool while operating intake switch.
4. Are the DTC B1208 present and is parameter of "Intake Potentiometer" fixed?
* Parameter of "Intake Potentiometer" will be fixed at 100% (or any value above 90%), or 0% (or any value below 10%), if there is any fault in Intake potentiometer.
YES - Go to "Inspection" procedure.
NO - 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.
TERMINAL AND CONNECTOR 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 - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Signal circuit inspection" procedure.
SIGNAL CIRCUIT INSPECTION
1. Check for open in harness.
1. Ignition "OFF"
2. Disconnect Intake potentiometer.
3. Measure resistance between terminal "6" of Intake Potentiometer and terminal "24" of A/C control unit.
Specification : Approx. 0 ohms
4. Is the measured resistance within specifications?
YES - Go to "Check for short to ground in harness" procedure.
NO - Check for open in signal harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
2. Check for short to ground in harness.
1. Ignition "OFF"
2. Disconnect Intake potentiometer.
3. Measure resistance between terminal "6" of Intake Potentiometer and chassis ground.
Specification : Approx. Infinity ohms
4. Is the measured resistance within specifications?
YES - Go to "Power circuit Inspection" procedure.
NO - Check for short to ground in signal harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
POWER SUPPLY CIRCUIT INSPECTION
1. Check for short or open in harness.
1. Ignition "ON"
2. Connect Intake Potentiometer.
3. Measure voltage between terminal "5" of Intake Potentiometer and chassis ground.
Specification : Approx. 5 V
4. Is the measured voltage within specifications?
YES - Go to "Component inspection" procedure.
NO - Check for short or open in power harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check actuator motor.
1. Ignition "OFF"
2. Disconnect Intake Potentiometer.
3. Verify that the temperature actuator operates to the fresh position when connecting 12 V to the terminal "3" and grounding terminal "4".
4. Verify that the temperature actuator operates to the recirculation position when the connections are reversed.
5. Does the actuator work properly?
YES - Go to "Check potentiometer" procedure.
NO - 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.
2. Check potentiometer
1. Ignition "ON"
2. Connect Intake potentiometer.
3. Measure voltage between terminal "7" and "6" of Intake potentiometer while operating Intake switch.
Specification : Refer to the specifications
Specifications : Voltage value of Intake potentiometer as a function of position of Intake.
4. Is the measured voltage within specifications?
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 actuator and check for proper operation. If the problem is corrected, replace actuator and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode and then clear DTC.
2. Operate the vehicle and monitor the DTC on the scantool.
3. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.