B100A-RECIRCULATION SWITCH REQUEST INPUT CIRCUIT LOW (ATC)
For a complete wiring diagram Refer to Section 8W.
Theory of Operation
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.
- When Monitored:
With the ignition on.
- Set Condition:
If the Recirculation mode switch stays in a pushed position for more than 10 minutes.
| Possible Causes |
| A/C HEATER CONTROL DAMAGED |
| OBJECT HOLDING RECIRCULATION MODE SWITCH IN A PUSHED POSITION |
| SUBSTANCE CAUSING RECIRCULATION MODE SWITCH TO GET STUCK IN A PUSHED POSITION |
| A/C
HEATER CONTROL |
Diagnostic Test
1. INSPECT THE A/C HEATER CONTROL FOR DAMAGEInspect the A/C Heater Control for damage.
Is the A/C Heater Control damaged?
Yes
- Replace the A/C Heater Control in accordance with the Service Information.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 2
2. INSPECT FOR OBJECT OR SUBSTANCE CAUSING THE RECIRCULATION MODE SWITCH TO STAY OR STICK IN A PUSHED POSITION
Inspect the A/C Heater Control for anything that would cause the Recirculation mode switch to stay or stick in a pushed position.
Is anything present that would cause the Recirculation mode switch to stay or stick in a pushed position?
Yes
- Repair as necessary.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 3
3. CHECK FOR NORMAL RECIRCULATION MODE SWITCH & STATUS INDICATOR FUNCTION
Turn the ignition on.
Set the Mode control to any position between Panel and Floor.
Press the Recirculation mode switch on and off several times while observing the Recirculation status indicator.
Does the Recirculation status indicator turn on and off?
Yes
- Go To 4
No
- Replace the A/C Heater Control in accordance with the Service Information.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
4. VERIFY THAT DTC B100A–RECIRCULATION SWITCH REQUEST INPUT CIRCUIT LOW IS STILL ACTIVE
With the scan tool, erase HVAC DTCs.
Turn the ignition off, wait 10 seconds, and then turn the ignition on. Wait 10 minutes before proceeding.
With the scan tool, read HVAC DTCs.
Does the scan tool display active: B100A–RECIRCULATION SWITCH REQUEST INPUT CIRCUIT LOW?
Yes
- Replace the A/C Heater Control in accordance with the Service Information.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).