Powertrain, generic · Fuel and air metering, auxiliary emission controls

P00FF Body Control Module Requested MIL Illumination

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P00FF is an information code in the engine control module: the body control module has detected an emissions-relevant fault of its own and asks over the data bus for the check engine light. The engine module stores P00FF so that a generic OBD scanner can see why the MIL is on; the actual fault is stored in the body control module as B or U codes and must be read there. GM documents two cases – a 2020 Cadillac CT5 with climate flap actuator codes and 2025 full-size SUVs with U1962 – both cured by reprogramming the body control module, not by replacing parts. The mechanism matches other 'module requested MIL' codes such as P069E. P00FF itself causes no limp mode.

Likely causes

Emissions-relevant fault in the body control module or its sensors/actuators (own B/U codes)
Software or calibration fault in the body control module
Communication fault on the data bus
Engine control module faulty

Symptoms

  • Check engine light on without an engine fault
  • Other messages depending on the body module fault
  • Driving behaviour unchanged

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–300
Time0.3–1.5 h

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

Parts involved

body control moduledata busengine control module

Related codes

P0700P069EP2561P0AC4P26C8

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov, saabwisonline.com.