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 MANUALSJEEP2009COMMANDER OVERLAND, RWDREPAIR AND DIAGNOSISENGINE PERFORMANCEIGNITION SYSTEMFRONT CONTROL MODULE (FCM) - ELECTRICAL DIAGNOSTICSDTC TROUBLESHOOTINGB2337-HORN CONTROL CIRCUIT HIGHDIAGNOSTIC TEST

2009 Jeep Commander Overland, RWD

Diagnostic Test

2009 Jeep Commander Overland, RWDSECTION Diagnostic Test

TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase DTCs.
3. Operate the Horn Switch several times.
4. Cycle the ignition from on to off three times and leave on.
5. With the scan tool, read DTCs.
  Does the scan tool display: B2337 HORN CONTROL CIRCUIT HIGH?
  
  Yes
  - Go to step 2
  No
  - The conditions that caused this code to set are not present at this time. Using the SYSTEM WIRING DIAGRAMS as a guide, inspect the wiring and connectors.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK FOR A SHORTED HORN RELAY

Fig 1: Checking For An Open Horn Relay
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Install a known good relay in place of the Horn Relay.
3. Turn the ignition on.
4. With the scan tool erase DTCs.
5. Operate the Horn Switch several times.
6. Cycle the ignition from on to off three times and leave on.
7. With the scan tool, read DTCs.
  Does the scan tool display: B2337 HORN CONTROL CIRCUIT HIGH?
  
  Yes
  - Go to step 3
  No
  - Replace the original Horn Relay.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK THE (X4) HORN RELAY CONTROL CIRCUIT FOR A SHORT TO VOLTAGE

Fig 2: Checking Horn Relay Control Circuit For A Short To Voltage
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Remove the Horn Relay.
3. Remove the Front Control Module (FCM) in accordance with the Service Information.
4. Turn the ignition on.
5. Measure the voltage of the (X4) Horn Relay Control circuit.
  Is the voltage above 0.2 volts?
  
  Yes
  - Replace the Integrated Power Module (IPM) in accordance with the Service Information.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace the Front Control Module (FCM) in accordance with the Service Information.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .

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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.