803742 Mercury WASHER

Table 1
J1939 Code and Description    CDL Code and Description    Comments    
171-3
Ambient Air Temperature : Voltage Above Normal     3667-3
Aftertreatment #1 SCR Cabinet Air Temperature Sensor : Voltage Above Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    
171-4
Ambient Air Temperature : Voltage Below Normal     3667-4
Aftertreatment #1 SCR Cabinet Air Temperature Sensor : Voltage Below Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    
3031-3
Aftertreatment #1 DEF Tank Temperature : Voltage Above Normal     3134-3
Aftertreatment #1 DEF Tank #1 Temperature Sensor : Voltage Above Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    
3031-4
Aftertreatment #1 DEF Tank Temperature : Voltage Below Normal     3134-4
Aftertreatment #1 DEF Tank #1 Temperature Sensor : Voltage Below Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    
4337-3
Aftertreatment #1 DEF Doser #1 Temperature : Voltage Above Normal     3608-3
Aftertreatment #1 SCR Dosing Manifold Temperature Sensor : Voltage Above Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    
4337-4
Aftertreatment #1 DEF Doser #1 Temperature : Voltage Below Normal     3608-4
Aftertreatment #1 SCR Dosing Manifold Temperature Sensor : Voltage Below Normal     The code is logged.
The value of the parameter is set to a default value.
Dosing is disabled until the pressure is correct.    System OverviewThe sensor signal for the passive sensor is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the passive sensors is routed from the ECM to terminal 2 of each sensor connector.Diagnostics on the Caterpillar Electronic Technician (ET)Wiggle Test - The Wiggle Test allows you to monitor the status of the signals from the sensors.For additional information regarding the Wiggle Test, refer to the documentation that accompanies the Cat ET software.
Illustration 1 g03321196
Schematic for the passive sensors
Table 2
Troubleshooting Test Steps    Values    Results    
1. Check for Diagnostic Trouble Codes
A. Connect to Caterpillar Electronic Technician (ET).
B. Turn the keyswitch to the ON position.
C. Access the "Active Diagnostic Code" screen on Cat ET.
Wait at least 30 seconds in order for the diagnostic codes to become active.
D. Look for these active codes or logged codes:
1. -3
2. -4
   
Codes
   
Result: A -3 diagnostic code is active.
Proceed to Test Step 2.
Result: A -4 diagnostic code is active.
Proceed to Test Step 3.
This code will not become active during cold mode.
Result: For a diagnostic code that is logged but not currently active.
Proceed to Test Step 4.
   
2. Create a Short at the Sensor Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the suspect sensor.
C. Install the jumper wire between terminal 1 (sensor signal) and terminal 2 (sensor return) at the sensor connector.
D. Turn the keyswitch to the ON position.
E. Monitor the diagnostic codes on Cat ET. Check for an active -4 diagnostic code for the suspect sensor.
Wait at least 30 seconds in order for the diagnostic codes to become active.
F. Turn the keyswitch to the OFF position.
   
Short circuit recognized
   
Result: The -3 diagnostic code remains active for the suspect sensor.
There is an open in the harness.
Repair: Repair the wiring or replace the harness.
Verify that the repair eliminated the problem.
Result: A -4 diagnostic code became active after creating the short at the sensor connector.
The wiring is OK.
Repair: Replace the sensor.
Verify that the repair eliminated the problem.
   
3. Create an Open at the Suspect Sensor Connector
A. Turn the keyswitch to the OFF position.
B. Disconnect the sensor connector of the suspect sensor with the active -4 diagnostic code.
C. Turn the keyswitch to the ON position.
D. Monitor the diagnostic codes on Cat ET. Check for an active -3 diagnostic code for the suspect sensor.
Wait at least 30 seconds in order for the diagnostic codes to become active.
E. Turn the keyswitch to the OFF position.
   
Open circuit recognized
   
Result: The -4 diagnostic code remains active for the suspect sensor.
There is an open in the harness.
Repair: Repair the wiring or replace the harness.
Verify that the repair eliminated the problem.
Result: A -3 diagnostic code became active after disconnecting the sensor.
The wiring is OK.
Repair: Replace the sensor.
Verify that the repair eliminated the problem.
   
4. Perform the Wiggle Test
Carefully following this procedure is the best way to identify the root cause of an intermittent problem.
A. Turn the keyswitch to the ON position.
B. Use Cat ET to run the "Wiggle Test".
C. Slowly wiggle the wiring and the connectors between the P2 connector and the sensor. Slowly wiggle the wiring and the connectors between the P1 connector and the sensor. Pay particular attention to the wiring near each connector. Be sure to wiggle all of the wiring.
D. As you wiggle the wiring look for these problems.
1. Loose connectors or damaged connectors
2. Moisture on the connectors or the wiring
3. Damage that is caused by excessive heat
4. Damage that is caused by chafing
5. Improper routing of wiring
6. Damaged insulation
   
Wiggle test
   
Result: The wiring failed the Wiggle Test.
There is a problem with the wiring.
Repair: Repair the wiring or replace the wiring.
Verify that the repair eliminated the problem.
Result: The wiring passed the Wiggle Test.
The problem may be intermittent. Inspect the wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".
If the wiring looks OK, perform the following procedure.
1. Turn the keyswitch to the OFF position.
2. Disconnect the connectors. Carefully inspect the terminals for proper installation. Make sure that each terminal is clean and dry.
3. Insert a pin into each socket. Verify that each socket grips the pin firmly. Repair any problems.
4. Connect all connectors.
5. Verify that the problem is resolved.
6. Return the unit to service.
   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