DPB_a101_ecuFastWdTestFault

Missing Built-In Self Test (BIST) trigger didn't swicth off hydraulically or electrically as expected.

Live incidence rate

<0.01% (Extremely rare)

Vehicle messages

Power braking assist reduced
Braking may require increased effort

Impact

System will be running in fully degraded state. Braking may require increased effort. Hydraulic Boost Compensation will be triggered when driver pressed brake pedal.

Description

Missing Built-In Self Test (BIST) trigger didn't swicth off hydraulically or electrically as expected.

Cause

Erroneous safety logic (e.g. BIST of system IC either does not detect a correct BIST command or missing BIST commands), The failsafe logic test tests whether the watchdog of the system chip can be started with the first watchdog trigger signal from the BIST state machine. Additionally it is tested that the watchdog switches off hydraulically respective electrically if the BIST state machine is not triggered during the corresponding timeout times.

Clear condition

No internal issue is detected after changing operation cycle. If the condition persists, the DPB module may require replacement.

Models

Model Y 2025+

Visibility

customer, service-fix

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