C1600 — Chassis control module — internal fault

Causes

• Internal electronic failure or degraded PCB components inside the CCM
• Corrosion, water ingress or physical damage to CCM housing or connector
• Low or unstable battery voltage or poor ground connection
• CAN/LIN bus communication fault or short to battery/ground affecting the module
• Failed firmware or corrupted software configuration
• Incorrect or incomplete module coding/programming after replacement

Symptoms

• Malfunction indicator(s) related to ESP/ABS/traction/stability may illuminate
• Loss or intermittent loss of chassis-related functions (stability control, traction control)
• Communication warnings or multiple network-related fault codes present
• Unusual CAN bus-related behavior (other modules reporting loss of chassis data)
• Possible drivability or braking behavior changes depending on fail-safe state

What to check

• Read and record all stored DTCs and freeze-frame data with a factory-level scan tool (Xentry/Star) or equivalent
• Check battery voltage and charge state; verify proper battery terminals and jump-start history
• Inspect CCM connector and harness for corrosion, bent pins, water ingress, or mechanical damage
• Verify fuses and relays for the CCM power and ignition circuits
• Check main grounds for continuity and corrosion at chassis/engine/body grounding points
• Scan for related network/communication codes (U-codes) and module status messages

Signal parameters

• Battery / ignition supply: ~11–14.5 V with ignition ON, no significant voltage drop under load
• Ground continuity: near 0 Ω between module ground and vehicle negative
• CAN bus idle voltages: CAN_H and CAN_L approximately mid-rail (~2.5 V) with differential signaling present during activity
• CAN bus error/fault counters: look for high error frame counts or bus-off condition
• Module internal self-test/status flags as reported by dealer-level diagnostic tool

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