Volvo All Engines (2017 Emissions) Fault Code: P202D7A PID: ACM Aftertreatment Reagent Pressure Leakage

Volvo All Engines (2017 Emissions) Fault Code: P202D7A PID: ACM Aftertreatment Reagent Pressure Leakage

Circuit description
The aftertreatment control module (ACM) uses the aftertreatment diesel exhaust fluid (DEF) dosing pressure sensor value to adjust and maintain DEF pressure at the DEF dosing valve by controlling DEF pump speed. If the pressure decreases below expected value when the pump is in initial pressure build-up mode or if the pressure increases above expected value when pump is in idle speed mode, the ACM considers DEF pressure outside of normal operating range and indicates a malfunction in a DEF dosing pressure sensor.

Conditions for diagnostic trouble code (DTC)
Aftertreatment DEF Dosing Pressure Lower than expected

Observable symptoms
No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Empty tank
2) Aftertreatment DEF Line(s) Leakage
3) Aftertreatment DEF dosing valve Leakage
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump Leakage
5) Aftertreatment Diesel Exhaust Fluid (DEF) Pump Main Filter
6) Aftertreatment Diesel Exhaust Fluid (DEF) Pump Inlet Pre-filter
7) Combined tank unit Filter screen
8) Contamination or debris inside DEF tank

Detailed information
Possible engine de-rate