Actuator Pulse Count Performance (MTC)
B1090-ACTUATOR PULSE COUNT PERFORMANCE (MTC)
For a complete wiring diagram refer to Diagrams/Electrical.
Theory of Operation
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 B1090-Actuator Pulse Count Performance. 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.
- When Monitored:
With the ignition on.
- Set Condition:
If the A/C Heater Control detects a pulse count error while attempting to drive a door actuator. This DTC has a maturing time of 5 seconds and a de-maturing time of 10 seconds. If the DTC's status changes from active to stored, it will stay in memory for 100 ignition cycles.
Diagnostic Test
1.CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE & CONTROL CIRCUIT OPEN DTCs
Turn the ignition on.
With the scan tool, read active HVAC DTCs.
Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE or XXXX CONTROL CIRCUIT OPEN DTCs?
Yes
- Diagnose and repair the DTC(s).
No
- Go To 2
2.RUN THE ACTUATOR DTC DETECTION TEST
With the scan tool, erase HVAC DTCs.
Turn the ignition off, wait 10 seconds, and then turn the ignition on.
With the scan tool, select System Tests and then select Actuator DTC Detection. When the test is complete, select View DTCs.
Does the scan tool display any DTCs?
Yes
- Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the common circuits, diagnose and repair all short high DTCs and then all short low DTCs.
No
- Go To 3
3.RUN THE ACTUATOR CALIBRATION TEST
With the scan tool, select System Tests and then select Actuator Calibration Test. When the test is complete, select View DTCs.
Does the scan tool display any DTCs?
Yes
- Diagnose and repair the DTC(s).
No
- Go To 4
4.CHECK MODE, BLEND & RECIRCULATION DOOR OPERATION
Start the engine.
Set the blower to high speed.
Operate each door in all positions in one direction and then in the opposite direction while monitoring the following:
- For the Mode Doors, verify that air flows from each vent accordingly for the position selected on the A/C Heater Control.
- For the Blend Doors, verify that the airflow air temperature changes accordingly for the temperature range selected on the A/C Heater Control.
- For the Recirculation Door, verify that the sound of the air flow get louder as the recirculation door opens to bring in recirculated air or gets softer as the recirculation door closes to bring in fresh air.
Does each door operate properly?
Yes
- The condition causing the fault has cleared at this time.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
No
- Remove the door actuator of the affected door from the A/C Heater Housing Assembly. By hand, attempt to rotate the actuator in both directions. Inspect the A/C Heater Housing for damage, for disconnected, missing, or broken linkage, and for broken or binding doors. Repair as necessary.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test