Code
B0260
Generic
B — Body
Body Control Module Input Circuit Fault
Views:
UK: 8
EN: 10
RU: 10
AI status
Completed
Completed
100%
Causes
- Open or short in the input wiring harness
- Corroded, bent or loose connector pins at BCM or component
- Failed or stuck switch/sensor feeding the BCM input
- Short to battery voltage or to ground (including chafed insulation)
- Faulty BCM input driver or internal BCM damage
- Blown fuse, poor power supply or low battery voltage
Symptoms
- One or more body functions operate intermittently or not at all (locks, lights, wipers, mirrors)
- Malfunction indicator or BCM warning lamp illuminated
- Stored DTC(s) and possible freeze-frame data available in scan tool
- Unreliable or inconsistent switch behavior (e.g., door ajar false status)
- Possible communication errors with other modules if BCM input influences network
What to check
- Read BCM DTCs and freeze-frame data with a capable scan tool; note which input/pin is referenced
- Inspect related wiring and connectors for damage, corrosion, water, or pin misalignment
- Verify battery voltage is within spec (12.4–14.5 V with engine running) and check fuses/relays for BCM power/ignition feeds
- Backprobe the BCM input pin and the component connector to compare voltages while operating the switch/sensor
- Perform continuity and resistance checks between BCM pin and component connector with ignition off
- Wiggle test harness and connectors while observing live data for intermittent changes
Signal parameters
- Typical input states: low ~0 V (ground) or high ~battery voltage (~12 V) for switched B+ inputs
- Some logic/IC inputs may use a 5 V reference; expected idle and active voltages depend on circuit type
- Open circuit: input floats (voltage unpredictable) or reads near infinite resistance
- Short to ground: input reads ~0 V continuously; short to B+: reads ~12 V continuously
- Expected input current: low (usually
Diagnostic algorithm
- Connect a scan tool, record DTC details, freeze-frame and live data. Identify the affected input and associated function(s).
- Verify battery voltage and check BCM power/ignition fuses and relays. Repair as needed before further diagnosis.
- Visually inspect connectors and wiring along the entire circuit path (BCM to component). Look for chafing, corrosion, water, or aftermarket splices.
- With ignition ON, backprobe the BCM input terminal and the component connector. Operate the switch/sensor and observe voltage changes on both ends. Compare to expected signal parameters.
- With ignition OFF, measure continuity/resistance between the BCM input pin and the component connector. Confirm no unexpected short to ground or battery. Typical continuity should be near 0 ohms; open/infinite indicates break.
- If a short is suspected, isolate sections of harness (disconnect connectors) and recheck to locate shorted segment.
- Perform a wiggle/stress test on wiring and connectors while monitoring live data for intermittent faults.
- If the wiring and sensor test good, bench-test or substitute the suspected switch/sensor if possible.
- If all external wiring and components verify good, consider BCM internal fault. Confirm by re-checking all circuits and, if available, substituting a known-good BCM or consulting manufacturer repair procedures before replacing the BCM.
- After repairs, clear codes and verify repair by cycling the function and performing a road/operation test to ensure the fault does not return.
Likely causes
- Damaged harness near door hinges, body panels or bulkhead (pinch/abrade)
- Connector corrosion or poor pin retention at BCM or sensor
- Failed door lock switch, courtesy lamp switch, or other body switch
- Intermittent wiring break causing signal to float
- Aftermarket accessory improperly tied into BCM circuits
- BCM internal fault (less common) after wiring verified
Fault status
Status
BCM input circuit fault detected: the module observed an invalid or out-of-range signal (stuck high, stuck low, open or intermittent) on a monitored input. A DTC was stored and diagnostic data recorded; inspect wiring, connectors and the originating switch/sensor before replacing the BCM.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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