Network, generic (extended)

U3003 Battery Voltage

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U3003 is logged when the supply a module measures at its own pins leaves the band it needs; the byte gives the direction: :16 too low, :17 too high, :1C out of range, :68 a logged event. GM's front camera module sets it below 9.0 V or above 16.0 V after 3 s in Run and then switches off adaptive cruise, without MIL. Mazda's MT-006/18 links U3003:16 in the CX-5 and CX-9 power liftgate module to a flat battery: recharge, reset, done. Volvo's TJ 34142 ties PSCM U30031C at cranking in start/stop cars to a battery support module switch and asks for both batteries above 12.4 V; Ford's SSM 49662 reports U3003:68 in the 2018 F-150 steering module after auto start-stop on a low battery. Each module stores its own entry, so several at once point to the battery or charging.

Likely causes

Low state of charge or aged 12 V battery
Alternator or DC/DC converter charging too little or too much
Voltage dip while cranking or restarting in start/stop mode
Corroded fuse, connector or ground in the feed to that module

Symptoms

  • Comfort or assistance function inoperative, e.g. power liftgate or adaptive cruise
  • Reduced steering assist message during cranking or after start-stop
  • The same code stored in several modules at once

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–300
Time0.3–1.5 h

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

Parts involved

batteryalternatorcharging system

Related codes

P0562P0563P0560U3006U3000

References: gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.