Volvo All Engines (2017 Emissions) Fault Code: P204900 PID: ACM Aftertreatment Reagent Dosing Valve Short Circuit High

Volvo All Engines (2017 Emissions) Fault Code: P204900 PID: ACM Aftertreatment Reagent Dosing Valve Short Circuit High

Circuit description
When the aftertreatment selective catalytic reduction (SCR) system operates under normal conditions, the aftertreatment control module (ACM) monitors diesel exhaust fluid (DEF) dosing valve duty cycle and DEF pump control value. When the DEF dosing valve duty cycle increases above allowed threshold and the DEF pump control value decreases below expected threshold, the ACM stops DEF dosing and reports a fault. Only certain mechanical failure or blockage in the DEF dosing valve or DEF supply line from the DEF tank will result with this fault, it is not a indication of an electrical fault.

Conditions for diagnostic trouble code (DTC)
Short circuit to battery voltage on A137:44

Observable symptoms
No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Short circuit to voltage supply, Control wire (-)
2) Short circuit to 5V, Control wire (-)
3) Connector
4) Wiring harness
5) Aftertreatment DEF dosing valve
6) Aftertreatment Control Module (ACM)