PIN AS 2577688 - Caterpillar

NRS Valve Circuit - Test
Table 1
Diagnostic Trouble Codes
Code Description Conditions Notes
523574-4 EGR Actuator Coil Short Battery voltage is normal.
EGR actuator coil short error signal received via CAN for 3 seconds or more. EGR Stop
Warning Level 1
Engine Derates 25%
Intake Throttle fully open
523572-4 EGR Position Sensor Failure Battery voltage is normal.
EGR position sensor error signal receives via CAN for 3 seconds or more.
523578-2 No communication with EGR Battery voltage is normal.
Starter switch signal is not activated.
Interruption of CAN communication for 1.3 seconds or more. Note: The 523578-2 is also often caused by a harness problem.
Illustration 1 g06111286
Table 2
Troubleshooting Test Steps Values Results
1. Check the voltage at the EGR connector terminals 3 and 4.
A. The voltage should be between 10 and 16 V.
Voltage
Result: If OK, then continue to Test Step 2.
Result: If not OK, then fault is in the harness.
Replace the engine harness
2. Check Continuity for CAN Communication Circuit Between EGR Connector Terminal and ECM Connector Continuity
Result: If NOT OK, then replace the engine harness.
Result: If OK, then replace the EGR valve. If this is an intermittent issue, it is likely a harness. Thoroughly inspect the harness before replacing the intake throttle.
Note: After repairing, run the engine until the coolant temp is above 65° C (149° F) to ensure that no diagnostic codes are created. Then perform an “EGR Valve Control Override” test in ET.NRS Valve Test
Table 3
Diagnostic Codes
Code Description Conditions Present Response
523572-4 EGR Position Sensor Failure Battery voltage normal
EGR control line is normal
EGR position sensor error signal received via CAN for 3 seconds or more. Engine derates 25%
EGR stops
Warning Level 2
523574-3 EGR Actuator Open Circuit Battery voltage is normal.
EGR actuator open error signal received via CAN for 3 seconds or more.
523574-4 EGR Actuator Coil Short
523575-7 EGR Actuator Valve Stuck
523576-2 EGR Motor Overheat
523577-2 EGR Motor Temperature Sensor Failure Note: These diagnostic codes are detecting internal failures of the EGR.Note: If code 523578-2 code is active. Resolve this code first.
Table 4
Troubleshooting Test Steps Values Results
1. Perform EGR Valve Control Override test in Cat ET EGR Valve Control Override Result: If OK, then EGR is operating normally.
Result: If NOT OK, then replace the EGR valve If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).