Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSJEEP2007GRAND CHEROKEE 2WD V6-3.7L VIN KREPAIR AND DIAGNOSISA L L DIAGNOSTIC TROUBLE CODES ( DTC )TESTING AND INSPECTIONB CODE CHARTSB100A
2007 Jeep Grand Cherokee 2WD V6-3.7L VIN K
B100A
2007 Jeep Grand Cherokee 2WD V6-3.7L VIN KSECTION B100A
B100A-RECIRCULATION SWITCH REQUEST INPUT CIRCUIT LOW (ATC)
For a complete wiring diagram refer to Diagrams/Electrical.
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.
Diagnostic Test
1. INSPECT THE A/C HEATER CONTROL FOR DAMAGE
Inspect the A/C Heater Control for damage.
Is the A/C Heater Control damaged?
Yes
- Replace the A/C Heater Control.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
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. Body Verification Test
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.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
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.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
No
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.