Code
C1391
Generic
C — Chassis
Chassis Control Module Internal Fault
Views:
UK: 5
EN: 6
RU: 5
AI status
Completed
Completed
100%
Causes
- Corrupted or failed module firmware/memory
- Intermittent or low supply voltage to the CCM (battery, charging system, fuse, wiring)
- Poor ground or high resistance in module ground circuit
- Damaged module connectors, pins, or wiring harness (corrosion, water intrusion)
- Internal hardware failure (processor, power regulator, solder joint, internal sensor)
- Excessive heat or moisture damage to module
Symptoms
- Chassis/vehicle stability systems reduced or disabled (ABS, ESC, traction control warnings)
- CCM warning lamp or generic chassis fault indicator illuminated
- Multiple related DTCs present (communication and sensor faults)
- Intermittent loss of chassis functions or degraded vehicle behavior
- Stored freeze‑frame/diagnostic data related to module status or communications
What to check
- Connect a diagnostic scan tool and read all current and historic DTCs and freeze‑frame data
- Note related U‑codes (communication errors) and C‑codes present with C1391
- Check battery voltage with engine off and during cranking; verify charging system voltage
- Inspect fuses and relays supplying the CCM
- Visually inspect CCM connector, pins and harness for corrosion, bent pins, water ingress or physical damage
- Backprobe and measure module supply voltage and ground resistance to chassis (compare to spec)
Signal parameters
- Module supply voltage (nominal battery voltage: ~11.5–14.5 V while running)
- Module ground resistance (should be low; verify good ground continuity)
- CAN bus idle voltages and differential waveform integrity (CAN_H/CAN_L idle and dominant levels)
- Fault/error counters and module internal status flags from scan tool
- Firmware/software/calibration part number and checksum status
- Module uptime and last reset reason (power on, watchdog reset, internal fault)
Diagnostic algorithm
- Connect a manufacturer or capable OEM-level scan tool; record C1391 plus all stored codes, freeze frame and OEM status info.
- Check battery and charging system; ensure battery is fully charged and terminals are clean and tight.
- Inspect CCM connector and harness for corrosion, water, bent pins or damage; repair any wiring/connector issues and reseat connector.
- Verify power and ground at the CCM: measure supply voltage and ground continuity to chassis ground. Repair any high resistance or open circuits.
- Check CAN/LIN bus: verify idle voltages, use scope to view waveforms and observe for bus errors or a dominant node. Disconnect suspected modules one at a time if needed to isolate bus fault.
- If external power/ground/communication circuits are good, attempt to reprogram/reflash CCM firmware per OEM procedure (check for available updates/TSBs).
- If reflash fails or C1391 persists after repair and verification of inputs, replace the CCM with a new/reconditioned unit and program/configure to the vehicle per OEM instructions.
- After repair or replacement, clear codes, perform functional tests of chassis systems and road test. Recheck for return of C1391 and for any related codes.
Likely causes
- Faulty module power/ground (low battery voltage, poor ground)
- Water intrusion or corrosion at module connector
- Module firmware corruption requiring reflash or update
- Failed internal electronic component (requires module replacement)
Fault status
Status
Chassis Control Module internal fault detected — module internal self-test or communications failed. Module may be unresponsive or reporting checksum/processor error.
Repair difficulty: Hard
Diagnostic time: 1-3 hours
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Code
C1391
MITSUBISHI
C — Chassis
INCOMP.learn neutral(Yawrate)
Views:
UK: 17
EN: 31
RU: 40
AI status
Completed
Completed
100%
Causes
- Corrupted or failed module firmware/memory
- Intermittent or low supply voltage to the CCM (battery, charging system, fuse, wiring)
- Poor ground or high resistance in module ground circuit
- Damaged module connectors, pins, or wiring harness (corrosion, water intrusion)
- Internal hardware failure (processor, power regulator, solder joint, internal sensor)
- Excessive heat or moisture damage to module
Symptoms
- Chassis/vehicle stability systems reduced or disabled (ABS, ESC, traction control warnings)
- CCM warning lamp or generic chassis fault indicator illuminated
- Multiple related DTCs present (communication and sensor faults)
- Intermittent loss of chassis functions or degraded vehicle behavior
- Stored freeze‑frame/diagnostic data related to module status or communications
What to check
- Connect a diagnostic scan tool and read all current and historic DTCs and freeze‑frame data
- Note related U‑codes (communication errors) and C‑codes present with C1391
- Check battery voltage with engine off and during cranking; verify charging system voltage
- Inspect fuses and relays supplying the CCM
- Visually inspect CCM connector, pins and harness for corrosion, bent pins, water ingress or physical damage
- Backprobe and measure module supply voltage and ground resistance to chassis (compare to spec)
Signal parameters
- Module supply voltage (nominal battery voltage: ~11.5–14.5 V while running)
- Module ground resistance (should be low; verify good ground continuity)
- CAN bus idle voltages and differential waveform integrity (CAN_H/CAN_L idle and dominant levels)
- Fault/error counters and module internal status flags from scan tool
- Firmware/software/calibration part number and checksum status
- Module uptime and last reset reason (power on, watchdog reset, internal fault)
Diagnostic algorithm
- Connect a manufacturer or capable OEM-level scan tool; record C1391 plus all stored codes, freeze frame and OEM status info.
- Check battery and charging system; ensure battery is fully charged and terminals are clean and tight.
- Inspect CCM connector and harness for corrosion, water, bent pins or damage; repair any wiring/connector issues and reseat connector.
- Verify power and ground at the CCM: measure supply voltage and ground continuity to chassis ground. Repair any high resistance or open circuits.
- Check CAN/LIN bus: verify idle voltages, use scope to view waveforms and observe for bus errors or a dominant node. Disconnect suspected modules one at a time if needed to isolate bus fault.
- If external power/ground/communication circuits are good, attempt to reprogram/reflash CCM firmware per OEM procedure (check for available updates/TSBs).
- If reflash fails or C1391 persists after repair and verification of inputs, replace the CCM with a new/reconditioned unit and program/configure to the vehicle per OEM instructions.
- After repair or replacement, clear codes, perform functional tests of chassis systems and road test. Recheck for return of C1391 and for any related codes.
Likely causes
- Faulty module power/ground (low battery voltage, poor ground)
- Water intrusion or corrosion at module connector
- Module firmware corruption requiring reflash or update
- Failed internal electronic component (requires module replacement)
Fault status
Status
Chassis Control Module internal fault detected — module internal self-test or communications failed. Module may be unresponsive or reporting checksum/processor error.
Repair difficulty: Hard
Diagnostic time: 1-3 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email