Volvo

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):
1) The voltage at pin A137:9 is below normal value

Observable symptoms
1) No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Open circuit, Common voltage supply
2) Short circuit to ground, Common voltage supply
3) Wiring harness
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump
5) Aftertreatment Control Module (ACM)

Detailed information
1) Possible engine de-rate

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):
1) The voltage at pin A137:7 is above normal value

Observable symptoms
1) 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) Wiring harness
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump
5) Aftertreatment Control Module (ACM)

Detailed information
1) Possible engine de-rate

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):
1) The voltage at pin A137:7 is below normal value

Observable symptoms
1) No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Short circuit to ground, Control wire (-)
2) Wiring harness
3) Aftertreatment Diesel Exhaust Fluid (DEF) Pump
4) Aftertreatment Control Module (ACM)

Detailed information
1) Possible engine de-rate

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):
1) Open circuit

Observable symptoms
1) No aftertreatment diesel exhaust fluid (DEF) dosage

Probable cause
1) Open circuit, Control wire (-)
2) Wiring harness
3) Aftertreatment Diesel Exhaust Fluid (DEF) Pump
4) Aftertreatment Control Module (ACM)

Detailed information
1) Possible engine de-rate

When ignition key is turned to OFF position the selective catalytic reduction (SCR) system enters afterrun mode. During afterrun, system attempts to drain diesel exhaust fluid (DEF) from the DEF dosing valve, DEF pump and DEF lines. Aftertreatment control module (ACM) activates DEF return valve by grounding the control wire (-). When the return valve is activated, the DEF reverses flow back to the tank, and DEF dosing pressure is expected to drop. If the dosing pressure does not drop or if it increases during afterrun, the return valve is considered to have a mechanical fault.

Conditions for diagnostic trouble code (DTC):
1) The voltage at pin A137:12 is above normal value

Observable symptoms
1) Aftertreatment Diesel Exhaust Fluid (DEF) Pump After-run not possible

Probable cause
1) Short circuit to voltage supply, Control wire (-)
2) Short circuit to 5V, Control wire (-)
3) Wiring harness
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump
5) Aftertreatment Control Module (ACM)

When ignition key is turned to OFF position the selective catalytic reduction (SCR) system enters afterrun mode. During afterrun, system attempts to drain diesel exhaust fluid (DEF) from the DEF dosing valve, DEF pump and DEF lines. Aftertreatment control module (ACM) activates DEF return valve by grounding the control wire (-). When the return valve is activated, the DEF reverses flow back to the tank, and DEF dosing pressure is expected to drop. If the dosing pressure does not drop or if it increases during afterrun, the return valve is considered to have a mechanical fault.

Conditions for diagnostic trouble code (DTC):
1) The voltage at pin A137:12 is below normal value

Observable symptoms
1) Aftertreatment Diesel Exhaust Fluid (DEF) Pump After-run not possible

Probable cause
1) Short circuit to ground, Control wire (-)
2) Short circuit to ground, Common voltage supply
3) Wiring harness
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump

When ignition key is turned to OFF position the selective catalytic reduction (SCR) system enters afterrun mode. During afterrun, system attempts to drain diesel exhaust fluid (DEF) from the DEF dosing valve, DEF pump and DEF lines. Aftertreatment control module (ACM) activates DEF return valve by grounding the control wire (-). When the return valve is activated, the DEF reverses flow back to the tank, and DEF dosing pressure is expected to drop. If the dosing pressure does not drop or if it increases during afterrun, the return valve is considered to have a mechanical fault.

Conditions for diagnostic trouble code (DTC):
1) Open circuit

Observable symptoms
1) Aftertreatment Diesel Exhaust Fluid (DEF) Pump After-run not possible

Probable cause
1) Open circuit, Control wire (-)
2) Open circuit, Common voltage supply
3) Wiring harness
4) Aftertreatment Diesel Exhaust Fluid (DEF) Pump

When ignition key is turned to OFF position the selective catalytic reduction (SCR) system enters afterrun mode. During afterrun, system attempts to drain diesel exhaust fluid (DEF) from the DEF dosing valve, DEF pump and DEF lines. Aftertreatment control module (ACM) activates DEF return valve by grounding the control wire (-). When the return valve is activated, the DEF reverses flow back to the tank, and DEF dosing pressure is expected to drop. If the dosing pressure does not drop or if it increases during afterrun, the return valve is considered to have a mechanical fault.

Conditions for diagnostic trouble code (DTC):
1) Aftertreatment DEF Dosing Pressure too high after ignition key is switched to OFF position

Observable symptoms
1) None

Probable cause
1) Frozen Aftertreatment Diesel Exhaust Fluid (DEF) Return Valve
2) Mechanical fault

This function monitors the efficiency of the exhaust gas recirculation (EGR) cooler. The EGR cooler efficiency is calculated from the measured EGR temperature, engine coolant temperature (ECT) and from the calculated turbine temperature.

Conditions for diagnostic trouble code (DTC):
1) Clogged radiator, EGR System