Network, generic

U01A3 Lost Communication With Hybrid/EV Battery Interface Control Module D

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

U01A3 marks a lost link to battery interface control module D. Before this generic block existed, GM used proprietary numbers for the same fault: the GM U-code list published for the 2011 Saab 9-4X names U2603 to U2606 as the battery energy control module losing hybrid battery interface modules 1 to 4. GM's 2018 hybrid table still groups these older numbers together with U01A0-U01AC and U179C in one fault bundle, so scan reports from different model years may show either form for the same board. In GM's 2016-2019 plug-in tables D is the fourth of eight boards and is rated Type A. One oddity to keep in mind: invalid data from module D is reported as U02A0, outside the U04A row used by its siblings.

Likely causes

Chain connection from module C to module D interrupted
Battery interface control module D defective
Scan tool or software generation reports the board under the older GM number

Symptoms

  • MIL and hybrid/EV warning (GM Type A)
  • Limited power, electric range shortened
  • Cell voltages of one pack section shown as unavailable

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,000
Time1–8 h

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

Parts involved

hv battery interface module dcommunication bus

Related codes

U01A2U01A4U02A0U033D

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