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U045A Invalid Data Received From Parking Assist Control Module A

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

Parking assist module A evaluates the ultrasonic sensors and in newer cars requests steering or braking for automated parking. U045A flags invalid data from it; U0159 is lost contact, U0544 covers module B. GM's brake module tables for the 2019 Cadillac XT4 (19OBDG03D) and 2020 (20OBDG03C) test counter and checksum of the parking brake request, a failure count rising by 2 per error and tripping at 3, within 0.2 s, Type C without MIL; the 2025 EBCM (25OBDG04B) wants 8 bad frames in 16. Ford's 2024 OBD summary rates U045A type 48 as non-MIL on cars with fully aided park assist. FCA TSB 08-011-15 (2014 Cherokee) fixes U045A-86 with new PAM software, Mercedes LI46.35-P-071804 lets E-Class steering units ignore U045A00, and Mazda's CX-5 camera logs U045A:68 after water entered sensor plugs. Park assist drops out.

Likely causes

Parking assist module software needing an update
Water or corrosion in ultrasonic sensor plugs or the bumper harness
Receiver storing the code as harmless history after a software change

Symptoms

  • Park assist or automatic parking unavailable
  • Parking sensor indicator flashing or false obstacle warnings
  • Emergency braking or collision warning message

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–900
Time0.3–3 h

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

Parts involved

parking assist module a

Related codes

U0159U0544U0243

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