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 MANUALSJEEP2010GRAND CHEROKEE LIMITED, 5.7 T, 4WDREPAIR AND DIAGNOSISENGINE PERFORMANCEENGINE CONTROL SYSTEMS(FRONT CONTROL MODULE (FCM) - ELECTRICAL DIAGNOSTICS)DTC TROUBLESHOOTINGB211B-IGNITION RUN/ACC/SPAD CONTROL CIRCUIT HIGHDIAGNOSTIC TEST

2010 Jeep Grand Cherokee Limited, 5.7 T, 4WD

Diagnostic Test

2010 Jeep Grand Cherokee Limited, 5.7 T, 4WDSECTION Diagnostic Test

CHECK FOR ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
1. Turn the ignition on.
2. Using the scan tool, read the active DTCs.
  Does the scan tool display this DTC as active?
  
  Yes
  - Go to step 2
  No
  - If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out or corroded terminals.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
(W12) REAR WIPER RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Identifying Rear Wiper Relay Control Circuit Terminal At Junction Block C1 Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Junction Block C1 harness connector.
3. Disconnect the IPM C2 harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (W12) Rear Wiper Relay Control circuit at the Junction Block C1 harness connector.
  Is the voltage above 10.0 Volts?
  
  Yes
  - Repair the (W12) Rear Wiper Relay Control circuit for a short to voltage.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Go to step 3
(W12) REAR WIPER RELAY CONTROL CIRCUIT SHORTED TO GROUND

Fig 2: Identifying Rear Wiper Relay Control Circuit Terminal At Junction Block C1 Harness Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Reconnect the IPM C2 harness connector.
3. Remove the FCM from the IPM.
4. Turn the ignition on.
5. Measure the voltage of the (W12) Rear Wiper Relay Control circuit at the Junction Block C1 harness connector.
  Is the voltage above 10.0 Volts?
  
  Yes
  - Replace the IPM in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the FCM in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .

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:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.