Control Module Wake-up Circuit/Open
The wake-up line that brings a sleeping ECU back from low-power mode is open. Many networks use a dedicated hardware wake-up wire (door-latch trigger, terminal 15, CAN wake-up) so modules can stay asleep with the ignition off. Without it, the module either fails to wake up at start-up or stays awake and drains the battery.
Affected components
- Wake up circuit
- Control module
- Wiring harness
Common causes
- High likelihood: Broken wake-up wire or unplugged connector
- Medium likelihood: Failed wake-up input stage in the module
- Low likelihood: Pin pushed back out of connector body
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.