P2ACC code meaning
Reductant Temperature Sensor B Circuit
Powertrain system Generic code P2Axx codes Check engine light
What P2ACC means
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.
P2ACC at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2ACC
- Check engine light and DEF/SCR warning
- Countdown or speed limitation if the fault persists
Common causes of P2ACC
- Most likelyConnector of sensor B corroded by DEF residue
- PossibleDamaged wiring between sensor B and the controller
- PossibleDefective reductant temperature sensor B
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Reductant temperature sensor bWiring harnessReductant control module
What each part of P2ACC means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| CC | The exact fault in that area. |
What to do next
- Note P2ACC and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2ACC
What does P2ACC mean?
P2ACC means "Reductant Temperature Sensor B Circuit". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2ACC?
Drive gently and only to a workshop. With P2ACC the car can go into limp mode (reduced power) to protect itself.
Will P2ACC fail an emissions test?
Yes, it can. P2ACC is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2ACC to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will P2ACC clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.