Powertrain, generic (extended)

P2ACC Reductant Temperature Sensor B Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2ACC is the general circuit code for a second reductant (DEF) temperature sensor outside the tank; the tank sensors have their own series (P205A ff. and P2ADA ff.). Sensor A, coded P2042 ff., is placed by Deutz in the SCR supply path (SPN 4337) and by Volvo and Mack in the DEF pump. Where a B sensor sits is left to the maker, and no manufacturer publicly documents P2ACC. The code captures circuit faults that do not fall clearly under the low or high codes P2ACE and P2ACF. CARB requires circuit monitoring for every input that feeds an emission control. Because DEF heating and the release of dosing depend on this temperature, an SCR warning and, if the fault stays, the usual inducement steps may follow.

Likely causes

Connector of sensor B corroded by DEF residue
Damaged wiring between sensor B and the controller
Defective reductant temperature sensor B

Symptoms

  • Check engine light and DEF/SCR warning
  • Countdown or speed limitation if the fault persists

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

reductant temperature sensor bwiring harnessreductant control module

Related codes

P2ACDP2ACEP2ACFP2AD0P2042

References: law.cornell.edu, serdia.deutz.com, static.nhtsa.gov.