Network, generic

U0253 Lost Communication With Accessory Protocol Interface Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The accessory protocol interface module is Ford's SYNC computer (APIM), which connects touchscreen, phone and voice functions with the vehicle network. Other modules log U0253 when its frames stop arriving, and Ford bulletins show several listeners: the headlamp module of the 2017 Lincoln MKZ after a remote start, cured by new HCM software (SSM 46508); the FCIM switch panel of 2015-2017 F-150 trucks, which froze under heavy CAN load (SSM 46902); and the ABS module of the 2021 F-150 with U0253:00, an informational entry without symptoms that new ABS software removed (SSM 50290, 51329). Mach-E owners (2021-2023) saw the drive mode reset to normal while driving because of APIM software, and the ABS sometimes held U0253 as well (TSB 24-2012). Settings sent from the screen may be lost.

Likely causes

APIM or receiving-module software fault, fixed by reprogramming or over-the-air update
APIM without power or ground (fuse, connector behind the center display)
Network overload or a module locking up after remote start or battery work
Internal failure of the SYNC module

Symptoms

  • Center screen dark, frozen or rebooting
  • Drive mode or settings fall back to default, message Drive Mode Not Available
  • Code stored in ABS, headlamp or switch module without noticeable fault

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–1,200
Time0.3–2.5 h

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

Parts involved

accessory protocol interface modulevehicle bus wiring

Related codes

U0554U031FU0256U0155

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.