C0825

Code

Generic C — Chassis

Chassis Control Module Communication Fault

Brand: Generic

Type: C — Chassis

Views: UK: 2 EN: 6 RU: 2

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open, shorted, or damaged CAN/LIN wiring or connectors
Corroded or loose module connectors or grounds
Faulty chassis control module or CAN transceiver
Improper or missing bus termination (open/shorted terminating resistors)
Low battery/voltage supply or intermittent power to module
A different module driving the bus into 'bus off' or causing network errors

Symptoms

ABS/ESC/traction control warning lights or restricted functionality
Loss of chassis-related functions (stability control, hill assist, etc.)
Multiple disparate DTCs from other modules reporting lost communication
Intermittent or permanent faults that may clear and return
Unresponsive vehicle controls tied to the CCM

What to check

Connect a diagnostic scan tool and confirm C0825 plus any other active/pending codes
Record module communication status, bus-off counters, and freeze frame data
Verify vehicle battery voltage (>11.5 V) and charging system operation
Visually inspect CCM connector for corrosion, bent pins, or water ingress
Inspect CAN/LIN wiring harness along route for damage, chafing, or repairs
Perform wiggle test of wiring and connectors while monitoring network status

Signal parameters

CAN bus idle voltages: CAN_H ≈ 2.5 V, CAN_L ≈ 2.5 V (differential ~0 V); dominant: CAN_H ≈ 3.5 V, CAN_L ≈ 1.5 V
Typical CAN termination: two 120 Ω resistors in parallel ≈ 60 Ω across CAN_H and CAN_L
Common CAN bitrates: 125 kbps, 250 kbps, 500 kbps (confirm vehicle-specific bitrate)
Expected continuity: low resistance between module ground and chassis (
Supply to module: near battery voltage when key on (typically >11.5 V)

Diagnostic algorithm

Retrieve and record all DTCs from all modules; note if other modules report lost comms.
Verify battery voltage and charging system; ensure stable supply during testing.
Visually inspect CCM connector and harness for damage, corrosion, water entry, or repair splices.
Check module grounds and supply fuses; repair any loose or corroded ground connections.
Measure CAN termination resistance at the CCM connector (expect ~60 Ω).
With a scope or CAN bus analyzer, observe CAN_H and CAN_L waveforms for noise, missing frames, or stuck dominant/recessive states; identify if a specific node is flooding the bus.
Perform wiggle tests on harness and connectors while monitoring network messages to reproduce intermittent failures.
If bus and harness check OK, try swapping or bench-testing the CCM if procedures and an equivalent known-good module are available (avoid replacing module without verifying harness).
If module replacement or reprogramming is required, follow manufacturer programming/configuration procedures and retest network operation.
Clear codes and perform a complete test drive while monitoring for return of the fault.

Likely causes

Corroded connector or poor ground at the CCM
Wiring chafing or pinched CAN pair near wheels or body harness
Failed CAN transceiver inside CCM
Battery/charging system voltage too low during communication
Another node repeatedly transmitting causing bus errors (faulty sensor/module)

Fault status

⚠️ Status

Chassis Control Module Communication Fault: intermittent or lost communication detected on vehicle data bus (CAN/LIN), requiring network, wiring, power/ground, and module checks.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours