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.
Diagnostic Test
- INTERMITTENT CONDITION
- Turn the ignition on.
- Using the scan tool, clear all FCM DTCs.
- Turn the Right Turn Signals on.
- With the scan tool read the DTC information.
Does the scan tool read: B1647-REAR RIGHT TURN CONTROL CIRCUIT LOW?
Yes
- Go To 2
No
- The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- L62 REAR RIGHT TURN SIGNAL CONTROL CIRCUIT
- Turn the ignition off.
- Disconnect the IPM C2 connector.
- Disconnect the Right Rear Tail Lamp connector.
- Measure the resistance between ground and the (L62) Rear Turn Signal Control circuit.
Is the resistance below 5.0 Ohms?
Yes
- Repair the (L62) Rear Right Turn Signal Control circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Go to step 3
- FRONT CONTROL MODULE
- Turn the ignition off.
- Disconnect the Front Control Module from the IPM 49-way connector.
- Measure the resistance between ground and the (L62) Right Turn Signal Control circuit in the PDC.
Is the resistance below 5.0 Ohms?
Yes
- Replace the Power Distribution Center in accordance with the service information.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Replace the Front Control Module in accordance with the service information.
- Perform the BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
Use the Manual With the Right Hardware
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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.
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