422400 Volvo.Penta Bracket

Table 1
Diagnostic Codes Table    
Code    Conditions which Generate this Code    System Response    
168-0 Electrical System Voltage : High     The battery supply voltage is greater than 32 VDC for 0.5 seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.     The code is logged.    
168-1 Electrical System Voltage : Low     The battery supply voltage is less than 18 VDC for 0.5 seconds.
The engine's ECM has been powered for three seconds.
The engine is not being cranked.    
168-2 Electrical System Voltage : Erratic, Intermittent, or Incorrect     The engine is running. The battery voltage falls below 6 VDC and the voltage returns above 9 VDC for three voltage readings in the last seven seconds.    Unswitched battery voltage is supplied through the customer connector to the ECM at P1-48, P1-52, P1-53, and P1-55. The negative battery is supplied to the ECM at P1-61, P1-63, P1-65, and P1-69. The ECM receives the input from the keyswitch at P1-70 when the keyswitch is in the ON position or the START position. When the ECM detects battery voltage at this input, the ECM will power up. When battery voltage is removed from this input, the ECM will power down.The cause of an intermittent power supply to the ECM can occur on either the positive side or the negative side of the battery circuit. Both sides are routed from the ECM to the battery. The four connections for the unswitched +Battery should be routed through a dedicated protective device (circuit breaker).The engine ECM requires the keyswitch to be in the ON position in order to maintain communications with the electronic service tool.
Illustration 1 g01820735
Schematic diagram for the electrical power supplyTest Step 1. Inspect the Electrical Connectors and the Wiring
Check all circuit breakers.
Check the battery.
Remove electrical power from the engine ECM.
Turn the keyswitch to the OFF position.
Illustration 2 g01167488
ECM connectors (typical example) (1) J1/P1 ECM connectors
Thoroughly inspect connectors (1) and (2). Inspect the connections for the battery and the connections to the keyswitch. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01745555
P1 terminals that are associated with the electrical power supply (P1-44) Shutdown (P1-48) +Battery (P1-52) +Battery (P1-53) +Battery (P1-55) +Battery (P1-61) −Battery (P1-63) −Battery (P1-65) −Battery (P1-69) −Battery (P1-70) Keyswitch
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the electrical power supply.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasions and for pinch points from the battery to the ECM. Also, check the harness and wiring for abrasions and for pinch points from the keyswitch to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The connectors and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.STOPTest Step 2. Check the Battery Voltage at the ECM
Disconnect the J1/P1 ECM connector.
Restore electrical power to the engine ECM.
Turn the keyswitch to the ON position.
Measure the voltage between P1-52 (Unswitched Positive Battery) and P1-63 (Negative Battery).
Measure the voltage between P1-48 (Unswitched Positive Battery) and P1-61 (Negative Battery).
Measure the voltage between P1-53 (Unswitched Positive Battery) and P1-65 (Negative Battery).
Measure the voltage between P1-55 (Unswitched Positive Battery) and P1-69 (Negative Battery).
Measure the voltage between P1-70 (Keyswitch) and P1-63 (Negative Battery).Expected Result:The measured voltage is between 11.0 VDC and 13.5 VDC for a 12 volt system and between 22.0 VDC and 27.0 VDC for a 24 volt system with no suspected intermittent problems at this time.Results:
OK - The ECM is receiving the correct voltage. Repair: If an intermittent condition is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - The battery voltage is out of the acceptable range. Proceed to Test Step 3.
Not OK - The voltage is out of the acceptable range.Repair: Check the circuit protection for the circuit and for the wiring. Trace the wiring for the keyswitch from the ECM through the keyswitch circuit to the batteries. Find the problem and repair the problem. Verify that the repairs eliminate the problem.STOPTest Step 3. Check the Batteries
Measure the no-load battery voltage at the battery posts.
Load test the batteries. Use the 4C-4911 Battery Load Tester. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6, 8 and 12 Volt Lead Acid Batteries" and Special Instruction, SEHS7633, "Battery Test Procedure".Expected Result:The batteries pass the load test. The measured voltage is the minimum specification for a 12V or 24V system.Results:
OK - The batteries are OK.Repair: Check the wiring between the batteries and the ECM for shorts.Check the connectors between the batteries and the ECM for moisture and/or corrosion.Repair the wiring and/or the connectors.Verify that the repair eliminates the problem.STOP
Not OK - The battery voltage is low or the battery did not pass the load test.Repair: Recharge or replace the faulty batteries. Verify that the repair eliminates the problem.STOP