Powertrain, generic (extended)

P202D Reductant Leakage

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P202D reports that DEF is escaping somewhere between pump and dosing valve, which the controller typically notices as a pressure that cannot be held. Volvo and Mack use it on their 2014 and later trucks (OBD13 onwards). A 2015 tech tip handles it together with P208E and P20E8 and names poor electrical contact, which makes the pressure reading look low, and contamination that really lowers it. 2023 bulletins CBR-2298 and CBR-2303 add crystal crusts, a clogged tip or a weeping dosing valve, yet stress that returned valves were mostly fine: the valve is replaced only if a dosing test shows reduced flow. White urea crust on lines or the valve is a typical sign. CARB requires reductant delivery to be monitored. Neglected, the system cannot hold pressure, NOx rises and inducement follows.

Likely causes

Dosing valve weeping or crusted with crystals
Leaking DEF line, fitting or seal
Poor electrical contact faking a pressure loss
Contaminated DEF lowering system pressure

Symptoms

  • Malfunction indicator lamp on
  • White crystalline deposits on DEF lines or dosing valve
  • Higher DEF consumption, later inducement warnings

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,200
Time0.5–3 h

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

Parts involved

reductant supply linereductant pumpreductant injection valve

Related codes

P208EP20E8P204F

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.