Serial Communication Link
A general fault on a serial communication link - typically used by older single-wire diagnostic protocols (KWP2000, ISO 9141) before CAN became universal. ECU has lost or corrupted communication with another module.
Affected components
- Serial communication bus
Common causes
- High likelihood: Harness fault on bus line
- Low likelihood: Gateway module routing CAN messages incorrectly
- Low likelihood: CAN terminating resistor (120 Ω) drifted out of spec
Possible symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.