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.
Code B336 - Loss Of IPC Data: Notes
If BCM loses data communication with IPC and ignition is on, code B336 will be set. The problem is a result of 7-volt or ground fault to IPC or double open circuit in data communication line between IPC and BCM. If this failure occurs, cruise control will disengage (if engaged) and headlights (if on) will function on low beam.
- Checks for an intermittent condition.
- Checks if problem is related to power and ground circuits or data communication line.
- Determines if data problem is due to IPC or wiring.
- Determines if fault is due to an open in circuit Nos. 800E and 800C or an internal IPC problem.
- Checks if fault is due to 7-volt power circuit or ground circuit from CPS.
- Checks ground circuit for an open, faulty IPC or a faulty CPS.
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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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