B02A0

Code

Generic B — Body

Body Network CAN Communication Fault

Brand: Generic

Type: B — Body

Views: UK: 4 EN: 3 RU: 2

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or shorted CAN_H or CAN_L wiring
Corroded/damaged connectors or pins in body wiring harness
Missing or incorrect termination resistors on CAN bus
Faulty BCM or another module pulling the bus down
Intermittent wiring/short to battery or ground
Aftermarket accessory or module interfering with the bus

Symptoms

Multiple body modules not responding or reporting errors
Door locks, windows, interior lights, remote functions intermittent or inoperative
Instrument cluster or message center shows communication warnings
Modules appear intermittently on scan tool or drop off the bus
Possible parasitic battery drain or unexpected module wake/sleep behavior

What to check

Read all current and stored DTCs from all modules with a capable scan tool
Verify which modules appear on the CAN network (module list)
Visually inspect connectors, fuses and wiring in the body harness and near BCM
Measure CAN_H and CAN_L voltages with ignition ON and key OFF states
Measure resistance across CAN_H and CAN_L with ignition OFF (expected ~60 Ω)
Check for shorts to battery or ground from CAN lines (resistance to B+ and ground)

Signal parameters

Idle/recessive voltage: CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (both same)
Dominant state: CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V (differential ≈ 2.0 V)
Typical differential voltage (dominant): ~1.5–3.0 V depending on system and load
Termination resistance (ignition off, full bus): ≈ 60 Ω measured across CAN_H–CAN_L (two 120 Ω terminators in parallel)
Open-circuit on bus: very high resistance; short to ground or Vb: near 0 Ω to respective rail

Diagnostic algorithm

Record all codes and freeze-frame data from BCM and other modules; note module presence/missing modules
Visually inspect BCM and body harness connectors for corrosion, bent pins, water intrusion or damage; repair as needed
With ignition OFF, measure resistance across CAN_H and CAN_L at BCM connector; expected ≈60 Ω; if open or very high, trace wiring and connectors
With ignition ON (engine off unless specified), measure idle voltages: CAN_H and CAN_L should be ~2.5 V; if one line is stuck to battery or ground, locate short
Check for shorts: measure resistance from each CAN line to B+ and to ground (should be high). If low, isolate by disconnecting modules until short disappears
Use scan tool to monitor live CAN frames and module presence; wiggle wiring and connectors while monitoring for intermittent dropouts
Disconnect suspected module(s) one at a time to identify a device causing bus failure; if removing a module restores bus communication, test/replace that module
Inspect for aftermarket devices; remove them and verify bus stability
If wiring and connectors are good, consider reflashing/reprogramming BCM or replacing a suspected faulty module per manufacturer guidance
After repairs, clear codes and verify repair by cycling ignition and driving cycle while monitoring BUS and relevant functions

Likely causes

Damaged connector/corrosion at a multi-pin body connector
Short to battery or ground on CAN_H or CAN_L near a body module
Loose or missing 120 Ω termination resistors (total ~60 Ω across bus)
Faulty BCM or other body module CAN transceiver
New aftermarket device added to bus without correct termination/isolation

Fault status

⚠️ Status

Body Network CAN Communication Fault — the body domain CAN bus is reporting communication failures or electrical characteristics outside expected limits. The BCM or one or more body modules may be unresponsive or causing the bus to fail.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours