C0100

Code

Generic C — Chassis

Chassis Control Module Communication Fault

Brand: Generic

Type: C — Chassis

Views: UK: 23 EN: 75 RU: 26

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Page language: EN

Read all stored and pending DTCs from all modules; record freeze frame data
Check battery voltage and charging system (stable 12V/charging during tests)
Visually inspect CCM connector and wiring for corrosion, damage or water ingress
Check CCM power and ground circuits at the module (measure battery voltage and ground resistance)
Use scan tool to attempt communication with CCM and observe message presence
Backprobe CAN H and CAN L at CCM and check idle voltages (~2.5 V) and differential behavior

CAN bus idle voltage (CAN High ~2.5 V, CAN Low ~2.5 V each relative to ground)
Differential voltage when active (CAN H rises, CAN L falls) typical peak-to-peak ~1.0 V
Typical CAN bus bit rates: 250 kb/s or 500 kb/s depending on vehicle (verify spec)
Termination resistance across CAN H-L ≈ 60 ohms (two 120 ohm terminators in parallel)
Expected periodic messages: module heartbeat/status, wheel speed, brake/ESP status (message frequency varies by vehicle)

Capture and note all DTCs from all modules and freeze-frame data. Look for related U-/C- codes.
Verify battery voltage and grounds; ensure stable supply during testing.
Attempt to communicate with CCM using a capable scan tool. Note if the module is present or 'no response'.
Visually inspect CCM connector and wiring harness for damage, corrosion, or water. Repair as needed.
Backprobe CAN H and CAN L at the CCM: measure idle voltages, then monitor with an oscilloscope or lab scope for proper differential signals and message traffic while cranking and driving.
Check termination resistance across CAN H-L with ignition off (~60 ohms). Remove suspect modules to isolate bus segments if necessary.
If short or open is found, trace and repair wiring; replace corroded connectors and boot seals. Retest communications after repairs.
If wiring and power/ground pass and bus traffic is normal but CCM does not respond, check for software updates or known service bulletins; attempt module wake/reset or reflash per manufacturer procedures.
If module firmware update or reset fails and all network checks are good, replace CCM and program/configure replacement as required. Clear codes and perform road test to verify cure.
If intermittent, perform wiggle tests and monitor while driving to reproduce and capture fault conditions; consider harness repair or protective routing.