OBD-II code · Powertrain (generic, extended)
P24EF 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.
Is it safe to drive with P24EF?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBroken wake-up wire or unplugged connector
- PossibleFailed wake-up input stage in the module
- Less likelyPin pushed back out of connector body
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Wake Up Circuit, Control Module, Wiring Harness
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.