VALVE AS-RELIEF 4P3546 - Caterpillar

MID ECM CID 0168 FMI 01Conditions Which Generate This Code:The system voltage is low. The following conditions are present The ECM has been powered up for three seconds, the engine is not cranking and the battery voltage is less than 9.0 VDC for at least 2 seconds. This diagnostic code indicates a problem in the battery charging system.Test Step 1. CHECK ELECTRICAL CONNECTORS AND WIRING.
Turn the keyswitch OFF.
Inspect the battery and the battery connections to the MJB.
Check the Allen Screw and the connectors on the PCP for the proper torque and attachment.
Check the harness and the wiring for corrosion, abrasion, pinch points or incorrect attachment from the MJB to the battery connections. Expected Result:All of the wiring and connections are properly mated and are in good condition.Results:
OK - All of the wiring and connections are properly mated and are in good condition. Go to Test Step 2.
NOT OK - All of the wiring and connections are NOT properly mated or are NOT in good condition.Repair: Repair as required.STOPTest Step 2. CHECK THE BATTERY VOLTAGE AT THE BATTERIES.Measure the voltage at the batteries.Expected Result:The voltage is between 22 VDC to 27 VDC for a 24 VDC system. The voltage should be between 11 VDC to 14 VDC for a 12 VDC system.Results:
OK - The voltage is between 22 VDC to 27 VDC for a 24 VDC system. The voltage is between 11 VDC to 14 VDC for a 12 VDC system. Go to Test Step 3
NOT OK - The voltage IS NOT correct. There is a problem with the battery charging circuit.Repair: If the battery voltage is low, recharge the batteries. If the problem continues, there is a problem with the alternator charging circuit. Refer to Special Instruction, REHS0354, "Charging System Troubleshooting". Repair as required.STOPTest Step 3. MEASURE THE VOLTAGE AT THE ECM.Measure the voltage at the ECM J1 connector. Refer to table 1 for the proper pin number combinations.
Table 1
Engine Measure From Circuit Name Measure to Result
3196
3406E J1-4 Switched +Battery J1-5 12 3VDC or 24 3VDC
J1-6 Unswitched +Battery J1-5
3412E
C30
C32 J1-23 Switched +Battery J1-5 24 3VDC
J1-4 Unswitched J1-5
J1-6 Unswitched J1-11
C9
C12
C15
C18
3126B J1-70 Switched +Battery J1-61 12 3VDC or 24 3VDC
J1-48 Unswitched J1-61
J1-52 Unswitched J1-63
J1-53 Unswitched J1-65 Expected Result:The voltage should be between 22 VDC to 27 VDC for a 24 VDC system. The voltage should be between 11 VDC to 14 VDC for a 12 VDC system.Results:
OK - The voltage is between 22 VDC to 27 VDC for a 24 VDC system. The voltage is between 11 VDC to 14 VDC for a 12 VDC system.STOP
NOT OK - The voltage IS NOT correct. There is a problem with the battery charging circuit.Repair: If the battery voltage is low, recharge the batteries. If the problem continues, there is a problem with the alternator charging circuit. Refer to Special Instruction, REHS0354, "Charging System Troubleshooting". Repair as required.STOP