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U0073Control module communication bus A off

Universal diagnostic code. Below: what it means, common causes, symptoms, and the exact bench-programming fix path.

Common causes

  • CAN-H or CAN-L short to ground
  • Missing 120-ohm terminator
  • Failed module shorting the bus

Symptoms you'll see

  • Multiple module no-comm
  • Crank-no-start in many cases
  • Cluster errors

The fix path

Diagnose wiring + terminators first. If a specific module is identified as the bus-killer, bench-repair or replace that module.

AML services that fix this

Mail in the affected module, we bench-program, ship back next business day. Flat pricing, return shipping included.

Related diagnostic codes

Not sure which service applies?

Text us your year/make/model + which scanner caught the code — we'll tell you exactly which module to ship and which service to pick.