What causes P1381 DTC?

[SteelGreenStallion]

P1381: Misfire detected-no communication with brake module.

Started getting a hesitation at light cruise~1800rpms. Checked the DTC's . This code P1381: misfire detected-no communication with brake module and P0300: random misfire detected showed up. What does the brake module have to do with a misfire? This is a LS swap car. There is no brake module.













p0300

[CranknChrome]

Need more info. What ecm and motor do you have? I think p1381 is for the variable cam timing module

[blindsquirrel]

What causes it is not having the ABS parts while leaving the DTCs for ABS comms enabled.

Why P1381 exists is because the ABS can determine (or make a guess) by the pattern from wheel speed sensors when it might be in 'rough road conditions', and it lets the PCM know to ignore anything misfire-related when that's happening, because the PCM can't on its own tell the difference in crankshaft speed variations caused by rough road conditions or caused by an actual misfire.