Powertrain, generic (extended)

P24F0 Control Module Wake-up Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P24F0 means that a control module drives its wake-up output on, but the line voltage stays down, pointing to a ground short or a load drawing far too much current. In GM's 2016 and 2019 hybrid tables the HPC2 module runs this check whenever the output is commanded on and reports a fault if the control voltage is at or below 5.52 V. Sampling every 12.5 ms, it needs 480 failures in a window of 560, roughly seven seconds; as a Type A code it lights the MIL on the first trip. The unit at the far end then never sees its wake signal and may stay off or drop out. Search the harness for a chafed spot or a wet connector. P24EF is the open-circuit fault, P24F1 the high one.

Likely causes

Wake-up line shorted to ground at a chafe point

Moisture in a connector bridging the line to ground

Receiving module loading the wake-up input too heavily

Symptoms

Malfunction indicator lamp on
Hybrid or charging functions unavailable

Repair estimate

DifficultyHardWorkshop job

Parts and labour€100–900

Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

wake up circuitcontrol module

Related codes

P24EF P24F1

References: gsi.ext.gm.com, gsi.ext.gm.com.