Theory Of Operation
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too few commutator pulses when calibrating the left blend door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too many commutator pulses when calibrating the left blend door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too few commutator pulses when calibrating the mode door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too many commutator pulses when calibrating the mode door, this DTC will set.
The A/C mode switch input changes when the switch is pushed down. A stored DTC 33 indicates that the A/C mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC 33 indicates that the A/C mode switch is stuck in a pushed position. An active DTC 33 will prevent the control from entering diagnostic mode and performing certain diagnostic functions. It will also prevent proper A/C mode switch and status indicator function. For additional information about the A/C Heater Control's on-board diagnostics, refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING.
The EBL mode switch input changes when the switch is pushed down. A stored DTC 34 indicates that the EBL mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC 34 indicates that the EBL mode switch is stuck in a pushed position. An active DTC 34 will prevent the control from performing certain diagnostic functions and it will prevent proper EBL mode switch and status indicator function. For additional information about the A/C Heater Control's on-board diagnostics, refer to DIAGNOSIS AND TESTING .
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects no commutator pulses when calibrating the left blend door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects no commutator pulses when calibrating the mode door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects no commutator pulses when calibrating the recirculation door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too few commutator pulses when calibrating the recirculation door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects too many commutator pulses when calibrating the recirculation door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects and excessive amount of commutator pulses when calibrating the mode door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects an excessive amount of commutator pulses when calibrating the left blend door, this DTC will set.
Note. Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 45, 46, 47, 51, 52, 53, 55, and 56).
The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the A/C Heater Control detects and excessive amount of commutator pulses when calibrating the recirculation door, this DTC will set.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
Note. This DTC will display as active if the ignition is not cycled after running the Actuator Circuit Test / Door Calibration Function. Otherwise, it will display as stored until cleared.
By running the Actuator Circuit Test / Door Calibration Function, the A/C Heater Control can identify up to three door driver circuits shorted simultaneously. A DTC 72 will set if more than three door driver circuits are shorted in the same direction (e.g. four door driver circuits all shorted to ground) or if two or more door driver circuits are shorted with at least one door driver circuit shorted to ignition and one door driver circuit shorted to ground. To ensure a proper diagnosis, diagnose and repair Actuator Circuit Test faults in the following order: If present, diagnose and repair DTC 72 first, then DTC 62, then DTC 61, then DTCs 64, 68, or 71, and finally DTCs 63, 67, or 69. In addition, always test the door driver circuits after each repair by clearing DTCs, and then running the Actuator Circuit Test / Door Calibration Function, and then checking for DTCs.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value is less than the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value exceeds the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control monitors the door driver circuits during actuator operation for conditions that prevent proper door operation. If a pulse count error is detected the A/C Heater Control reports the fault as a Actuator Performance DTC. It is important to note that this DTC only indicates that a fault occurred while driving a door actuator and that additional testing is necessary to provide more details about the reported fault.
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as Control Circuit/Performance DTCs.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value is less than the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value exceeds the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control monitors the door driver circuits during actuator operation for conditions that prevent proper door operation. If a pulse count error is detected the A/C Heater Control reports the fault as a Actuator Performance DTC. It is important to note that this DTC only indicates that a fault occurred while driving a door actuator and that additional testing is necessary to provide more details about the reported fault.
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as Control Circuit/Performance DTCs.
The switch input changes when the switch is pushed down. A stored DTC B100A indicates that the Recirculation mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC B100A indicates that the Recirculation mode switch is stuck in a pushed position. An active DTC B100A will prevent proper Recirculation mode switch and status indicator function.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value is less than the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value exceeds the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The switch input changes when the switch is pushed down. A stored DTC B1001 indicates that the A/C mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC B1001 indicates that the A/C mode switch is stuck in a pushed position. An active DTC B1001 will prevent proper A/C mode switch and status indicator function.
The switch input changes when the switch is pushed down. A stored DTC B1016 indicates that the EBL mode switch was stuck in a pushed position for more than 10 minutes, but has since returned to its normal state. An active DTC B1016 indicates that the EBL mode switch is stuck in a pushed position. An active DTC B1016 will prevent proper EBL mode switch and status indicator function.
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as Control Circuit/Performance DTCs.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value is less than the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after installing a new A/C Heater Control. Manual calibration occurs by sending a command with the scan tool. The purpose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the actuator, the A/C Heater Control first moves the door to its soft stop, and then counts the number of pulses it takes to move the door to its other stop. An expected range of span is stored in the control's memory. If the measured calibration value exceeds the expected range for this actuator, this DTC will set. Note that the control clears all stored calibration faults at the beginning of the calibration procedure.
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as Control Circuit/Performance DTCs.
An active DTC 33 will prevent the control from entering diagnostic mode and performing certain diagnostic functions, it will also prevent proper A/C mode switch and status indicator function. An active DTC 34 will prevent the control from performing certain diagnostic functions and it will prevent proper EBL mode switch and status indicator function. In addition, a short or an open (C41) Blower Switch Position Signal circuit will also prevent the control from entering diagnostic mode. For additional information about the A/C Heater Control's on-board diagnostics, refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING.
The HVAC System Test provides a starting point in the diagnostic process by identifying the appropriate diagnostic procedure or system test to perform when diagnosing a given symptom, condition, or DTC. It also provides a means for testing the entire HVAC system by utilizing the A/C Heater Control's On-Board System Tests. The On-Board System Tests can also assist in diagnosing stored DTCs. (Refer to HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING) for additional information about on-board diagnostics.
The HVAC System Test provides a starting point in the diagnostic process by identifying the appropriate diagnostic procedure or system test to perform when diagnosing a given symptom, condition, or DTC. It also provides a means for testing the entire HVAC system by utilizing the A/C Heater Control's On-Board System Tests. The On-Board System Tests can also assist in diagnosing stored DTCs. (Refer to HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING) for additional information about on-board diagnostics.