B162F

Code

Generic B — Body

Body Control Module internal fault

Brand: Generic

Type: B — Body

Views: UK: 14 EN: 18 RU: 12

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Page language: EN

Causes

Internal BCM hardware failure (processor, memory, solder joint)
Corrupted BCM firmware/calibration or failed reflash
Interrupted programming or low battery during a software update
Power supply problems to the BCM (low battery, voltage spikes, intermittent supply)
Poor ground or corroded connector pins at the BCM
Water/contamination ingress into BCM or connector

Symptoms

One or more body systems controlled by BCM operate intermittently or not at all (interior lights, central locking, wipers, windows, HVAC vents, etc.)
Scan tool cannot communicate with BCM or shows internal/self-test failures
Warning lights or general electronic system warnings on dash
Erratic behavior of lighting, door locks, or convenience functions
Parasitic battery drain or no-crank/starting problems if BCM controls starter circuit

What to check

Use a professional scan tool to read B162F plus any other stored codes and freeze-frame data
Record BCM part number, software/calibration ID, and programming date/time
Visually inspect BCM connector(s) and wiring for corrosion, bent pins, damage, or moisture
Check vehicle battery voltage and state of charge (resting and under load) and verify charging system output
Verify fuses and relays for BCM power and accessory circuits
Confirm solid ground(s) to the BCM (measure voltage drop between ground and chassis while cranking)

Signal parameters

Battery supply voltage at BCM pins (key-off, key-on, cranking)
Battery supply current draw from BCM (parasitic drain values)
Ground voltage drop and continuity values
CAN High/Low idle voltages (approx. 2.5 V differential) and CAN bus waveform integrity
CAN bus error counters / Tx-Rx error rates from scan tool
LIN bus voltages and message timing where applicable

Diagnostic algorithm

Connect a full-function scan tool. Read and record B162F plus all stored and pending codes, freeze frame data, and BCM software/calibration IDs.
Check battery voltage and charge if below manufacturer spec. Ensure stable power during testing and programming (use a battery maintainer if required).
Perform a visual inspection of the BCM enclosure and connectors for water, corrosion, heat damage or loose pins. Repair or clean as needed.
Verify power and ground circuits at the BCM: measure supply voltage at the module power pin(s) and verify ground continuity and low voltage drop to chassis.
Check CAN/LIN communication: confirm bus voltages and that other modules are communicating. Isolate the bus if necessary to see if one node is causing errors.
Review recent events: was the BCM recently replaced or reflashed? If a reflash failed or software mismatch is present, attempt a controlled reprogram/reflash per OEM procedure.
Clear codes and attempt to reproduce the fault. If B162F returns immediately or intermittently, capture diagnostics and raw data (waveforms, error counters).
If hardware fault is suspected after all wiring/power/communications checks, consult OEM service information for BCM bench tests or internal diagnostics. Follow OEM-approved reprogram/repair instructions.
If replacement BCM is required, verify correct part number and perform required module coding/programming and system relearns. Verify no related modules report communication errors after replacement.
After repair or reprogramming, road-test and re-scan to confirm the code does not return and that all body functions operate normally.

Likely causes

Corrupted or mismatched BCM software/firmware
Internal hardware/component failure inside the BCM
Unstable or insufficient battery/charging system voltage during operation or programming
Moisture or corrosion at BCM connectors or module housing
CAN/LIN bus short or heavy error conditions preventing normal module operation