20405721 Volvo.Penta Cap plug

The following background information is related to this procedure:Coolant Diverter ValveThe coolant diverter valve controls the flow of coolant to the heater in the Diesel Exhaust Fluid (DEF) tank. When required, the valve is opened to allow hot coolant to circulate through the DEF tank. This flow allows the coolant to heat the DEF to a useable temperature.DEF InjectorThe DEF injector controls the flow of DEF into the exhaust stream in the Clean Emissions Module (CEM). The DEF injector is controlled by the Dosing Control Unit (DCU).DEF Coolant Diverter Valve Solenoid OverrideThe override is used to check the solenoid and diverter valve harness. This override will open the coolant diverter valve, allowing coolant to flow through the Pump and Electronics Unit (PEU) . This test can be used to verify that the coolant diverter valve is working correctly.This override will only enable with the engine running at idle prior to the DEF system priming to operating pressure.DEF Dosing Injector OverrideThis override allows the user to test the electrical circuit for the DEF injector. The override commands the DEF injector to open. This override only operates when there is no engine speed.
Illustration 1 g03733173
Schematic for the solenoid valves
Not all connectors are shown. Refer to the appropriate Electrical Schematic.
Illustration 2 g03714645
Coolant diverter valve
Illustration 3 g03714646
DEF injector
Table 2
Troubleshooting Test Steps Values Results
1. Check the Battery Voltage
A. Turn the keyswitch to the OFF position.
B. Use a suitable multimeter to measure the battery voltage.
At least 12.5 V for a 12 V system
At least 25V for a 24V system
Result: The battery voltage is lower than the expected range.
Repair: Refer to Troubleshooting, Battery Problem to investigate the cause of low battery voltage.
Result: The battery voltage is within the expected range.
Proceed to Test Step 2.
2. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the 31-pin connector for the PEU. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
B. Thoroughly inspect the connectors for the coolant diverter valve and the DEF injector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the 31-pin connector and the solenoid connectors associated with the diagnostic code.
D. Ensure that the DCU connector is securely connected and locked in place.
E. Check the harness for corrosion, abrasion, and pinch points from the solenoids to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes.
Use the electronic service tool to perform the "Aftertreatment System Functional Test" to verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 3.
3. Check for Active Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position.
D. Use the electronic service tool to perform the "DEF Dosing Injector Override".
E. Verify if any of the diagnostic codes that are listed in Table 1 are active.
F. Start the engine.
G. Use the electronic service tool to perform the "DEF Coolant Diverter Valve Solenoid Override".
H. Verify if any of the diagnostic codes that are listed in Table 1 are active.
I. Turn the keyswitch to the OFF position.
Diagnostic codes
Result: A diagnostic code is active.
Proceed to Test Step 4.
Result: No diagnostic codes are active. There may be an intermittent fault.
Repair: Use the electronic service tool to perform a Wiggle Test.
If no faults are found, return the unit to service.
If the Wiggle Test identifies a fault, investigate the cause. Proceed to Test Step 5.
4. Check the Internal Resistance of the Suspect Component
For a suspect DEF injector, complete Steps A to C.
For a suspect coolant diverter valve, complete Steps D to F.
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the DEF injector.
C. Measure the resistance between pins 1 and 2 on the injector.
D. Turn the keyswitch to the OFF position.
E. Disconnect the connector for the coolant diverter valve.
F. Measure the resistance between pins 1 and 3 on the coolant diverter valve.
Internal resistance
Result: On a DEF injector, the measured resistance is less than 6.75 Ohms or more than 7.25 Ohms. There is a fault in the injector.
Repair: Install a replacement DEF injector.
Result: On a DEF injector, the