TUBE 1289557 - Caterpillar

Table 1
Diagnostic Trouble Codes for the Electrical Power Supply
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
168-3 168-3 Electrical System Voltage : Voltage Above Normal The ECM detects voltage that is above the acceptable value.
168-4 168-4 Electrical System Voltage : Voltage Below Normal The ECM detects voltage that is below the acceptable value.
3216-5 3002-5 Aftertreatment 1 Intake NOx : Current Below Normal The ECM detects current that is below the acceptable value
3216-6 3002-6 Aftertreatment 1 Intake NOx : Current Above Normal The ECM detects current that is above the acceptable value
3226-5 3609-5 Aftertreatment 1 Outlet NOx : Current Below Normal The ECM detects current that is below the acceptable value
3226-6 3609-6 Aftertreatment 1 Outlet NOx : Current Above Normal The ECM detects current that is above the acceptable value
3360-3 3820-3 Aftertreatment #1 DEF Controller : Voltage Above Normal The ECM detects voltage that is above the acceptable value.
3360-4 3820-4 Aftertreatment #1 DEF Controller : Voltage Below Normal The ECM detects voltage that is below the acceptable value.
4380-2 4592-2 Aftertreatment 1 Outlet NH3 Gas Sensor Power In Range : Erratic, Intermittent, or Incorrect The ECM detects that the power supply to the ammonia (NH3) sensor is not stable.
5758-11 3621-11 Engine Exhaust NOx Level Sensor Power Supply: Other Failure Mode The ECM detects voltage that is outside the acceptable value.
5759-11 3619-11 Aftertreatment #1 Outlet#1 NOx Level Sensor Power Supply: Other Failure Mode The ECM detects voltage that is outside the acceptable value. The engine ECM requires the keyswitch to be in the ON position to maintain communications with the electronic service tool.
Illustration 1 g03813883
Schematic diagram for the engine electrical power supply circuit
Not all connectors are shown. Refer to the appropriate electrical schematic
Illustration 2 g03813894
Schematic diagram for the DCU electrical power supply circuit
Not all connectors are shown. Refer to the appropriate electrical schematic
Illustration 3 g03813890
Schematic for the NOx sensor power supply circuit
Not all connectors are shown. Refer to the appropriate electrical schematic
Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Value Results
1. Determine the Diagnostic Code
A. Establish communication between the electronic service tool and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Start the engine. Run the engine until the engine is at normal operating temperature.
C. Observe the "Active Diagnostic" screen on the electronic service tool. Wait at least 30 seconds so that any codes may become active.
Diagnostic code
Result: One of the diagnostic codes listed in Table 1 is active.
Proceed to Test Step 2.
Result: The electronic service tool will not communicate with the ECM.
Repair: Refer to Troubleshooting, "Electronic Service Tool Does Not Communicate".
2. Inspect Electrical Connectors and Wiring
A. Ensure that the battery disconnect switch is in the CLOSED position.
B. Thoroughly inspect all connectors associated with the electrical power supplies.
C. Check all fuses.
D. Perform a 45 N (10 lb) pull test on each of the wires in the connectors associated with the electrical power supplies.
E. Check all the wiring associated with the electrical power supplies for abrasions and pinch points.
F. Verify that the "System Operating