848194 Volvo.Penta Hub

Illustration 1 g00953532
Schematic (typical example)Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect ECM connector J1/P1 and machine connector J3/P3. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Inspect the following components for damage, corrosion, and incorrect attachment:
Battery posts
Alternator
Breaker
Engine ground
Chassis groundExpected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points. All connections and grounds should be tight and free of corrosion.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit. Ensure that all of the seals are properly in place and that the connectors are completely coupled.Verify that the repair eliminates the problem. Stop.Test Step 2. Check Battery Voltage at the Batteries
Turn the keyswitch to the ON position.
Measure the voltage at the battery posts.Expected Result:The voltage should be between 22 VDC and 27 VDC.Results:
OK - The voltage is between 22 VDC and 27 VDC. Proceed to Test Step 3.
Not OK - The voltage is not between 22 VDC and 27 VDC.Repair: There is a problem with the batteries or the charging system. Refer to Testing and Adjusting, "Electrical System". Stop.Test Step 3. Check the Voltage at the ECM Battery Input
Illustration 2 g00953533
J1/P1 ECM connector
Turn the keyswitch to the OFF position and install a 140-2266 Adapter Cable (70 Pin Breakout T) at ECM connector J1/P1.
Turn the keyswitch to the ON position.
Measure the voltage between P1:48 (+Battery) and P1:63 (-Battery) at the breakout.
Connect an electronic service tool at the service tool connector.
Check for the following Logged Diagnostic Codes in order to determine if there is an intermittent problem with the +Battery circuit to the ECM:
168-00 "System Voltage High"
168-01 "System Voltage Low"
168-02 "System Voltage intermittent"Expected Result:The voltage should be within 1 VDC from the voltage at the battery posts.Results:
OK - Proceed to Test Step 4.
Not OK - There is an open circuit or excessive resistance in the wiring or connections between the batteries and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 4. Check the Voltage at the ECM
Turn the keyswitch to the ON position.
Measure the voltage between P1:70 (+Battery (switched)) and P1:63 (-Battery) at the breakout.Expected Result:The voltage should be between 22 VDC and 27 VDC.Results:
OK - The voltage is between 22 VDC and 27 VDC. Proceed to Test Step 5.
Not OK - The voltage is not between 22 VDC and 27 VDC. There is a problem in the wiring or the connections between the keyswitch and the ECM.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 5. Check the Analog Supply Voltage at the ECM
Illustration 3 g00953533
J1/P1 ECM connector
Turn the keyswitch to the ON position.
Measure the voltage between P2:2 (+V Analog Supply) and P2:3 (Analog Return) at the breakout.Expected Result:The voltage should be between 4.5 VDC and 5.5 VDC.Results:
OK - The voltage is between 4.5 VDC and 5.5 VDC. Proceed to Test Step 6.
Not OK - The voltage is not between 4.5 VDC and 5.5 VDC. Correct voltage is reaching the ECM.Repair: Perform the following procedure.
Disconnect ECM connector P1 and carefully examine the connector for loose terminals or corroded terminals.
Verify that the ECM is receiving the correct voltage from the keyswitch and from the batteries.
Reconnect ECM connector P1 and repeat this Test Step.
If the problem is not resolved, replace the ECM. Refer to Troubleshooting, "Replacing the ECM" before replacing the ECM. Stop.Test Step 6. Bypass the Engine Wiring Harness
Illustration 4 g00724036
Bypass circuitNote: The bypass is ONLY FOR TESTING. The bypass may be left on the engine temporarily. REMOVE THE BYPASS BEFORE YOU RELEASE THE ENGINE TO THE CUSTOMER. The ECM will be powered if the bypass switch is activated. The keyswitch must be placed in the ON position. The bypass switch must be activated for normal engine operation. The bypass switch must be deactivated in order to shut down the engine. Deactivate the bypass switch before you perform the following connection.
Illustration 5 g00953533
J1/P1 ECM connector
Remove the wires from P1:52 (+Battery) and P1:70 (+Battery (switched)).
Build the bypass circuit in Illustration 4.Note: Use black electrical tape on all temporary connections. Wrap the connections tightly. Keep the connections clean.
Connect the battery end of the bypass directly to the +Battery post.
Insert the sockets of the bypass into P1:52 (+Battery) and P1:70 (+Battery (switched)).
Install the temporary switch in the cab.
Operate the engine and try to duplicate the symptom.Note: If the symptom only occurs under certain operating conditions, test the engine under those conditions.Expected Result:Engine operation should be normal with the bypass in place.Results:
OK - There is a problem in the wiring that supplies power to the ECM. There is a problem in the wiring that supplies power to the switched +Battery input.