Volvo All Engines (2010 Emissions) Fault Code: SPN 3492 FMI 4 PID: PPID 340 Aftertreatment 1 Air System Relay

The Aftertreatment Hydrocarbon Dosing Module contains three non serviceable valves, the Aftertreatment Fuel Shutoff Valve, Aftertreatment Purge Air Valve and Aftertreatment Hydrocarbon Dosing Valve, and a serviceable Aftertreatment Fuel Pressure Sensor.
During Air Purge operation the Engine Control Module (ECM) sends a voltage signal to activate the Aftertreatment Purge Air Valve open. This allows air pressure to flow into the Aftertreament Hydrocarbon Dosing Module. The ECM then sends a PWM signal to the Aftertreatment Hydrocarbon Dosing Valve that allows purge air pressure to be monitored by a signal from the Aftertreatment Fuel Pressure Sensor to the ECM.

Conditions for diagnostic trouble code (DTC):
1) Voltage above normal or shorted high

Diagnostic operating conditions
1 )Output activated

Observable symptoms
1) Regeneration not possible

Probable cause
1) Connector
2) Engine wiring harness
3) Aftertreatment Hydrocarbon Dosing Module
4) Engine control module (ECM)