0384235 JOHNSON CARBURETOR ASSY.,Upper

Table 1
Diagnostic Codes Table    
J1939 Code     CDL Code     Code Description     Comments    
108-21     3528-21     Atmospheric Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
678-3     41-3     8 VDC Supply : Voltage Above Normal     The code is logged.    
678-4     41-4     8 VDC Supply : Voltage Below Normal     The code is logged.    
3358-21     3385-21     EGR Intake Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
3509-3     262-3     5 Volt Sensor DC Power Supply : Voltage Above Normal     The code is logged.
All sensors are set to default values.    
3509-4     262-4     5 Volt Sensor DC Power Supply : Voltage Below Normal     The code is logged.
All sensors are set to default values.    
3510-3     2131-3     5 v Sensor DC Power Supply #2 : Voltage Above Normal     The code is logged.
Engine power may be derated.    
3510-4     2131-4     5 v Sensor DC Power Supply #2 : Voltage Below Normal     The code is logged.
Engine power may be derated.    
3563-21     1785-21     Intake Manifold Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
3609-21     3464-21     DPF #1 Intake Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
3837-21     3493-21     Aftertreatment #1 Secondary Air Pressure Sensor : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
5578-21     289-21     Fuel Pressure Sensor - Before Fuel Filter : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    
5580-21     460-21     Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low     The code is logged.
The 5 VDC supply to the sensor has been lost.    System OperationThe Electronic Control Module (ECM) supplies a regulated voltage of 5.0 0.2 VDC to the sensors.The supply voltage for the sensors is routed from the ECM to terminal 1 of each sensor connector. The sensor return for the sensors is routed from the ECM to terminal 2 of each sensor connector. The ECM provides short circuit protection for the internal power supply. A short circuit to the battery will not damage the internal power supply.Note: The sensors are not protected from overvoltage. A short from the supply line to the +Battery may damage the sensors. If any of the diagnostic codes are active, a sensor may have been damaged. Repair the sensor supply and check for any active sensor diagnostic codes in order to determine if a sensor has been damaged.
Illustration 1 g01240891
Sensor connector (1) 5 V or 8 V sensor supply (2) Sensor return (3) Signal
Table 2
Sensor Supply     Sensor Supply ECM Location    
Sensor Supply #1     Sensors on A4:E4 engine ECM J2 connector or A5:E2 aftertreatment controller J2 connector    
Sensor Supply #2     Sensors on A4:E4 engine ECM J1 connector    
Illustration 2 g03390008
Note: The diagram above is a simplified schematic of the ECM - relay circuit. The schematic is electrically correct. However, not all of the possible sensors or harness connectors are shown. Refer to the latest revision of the Electrical Schematic for the complete schematic for your application.Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps     Values     Results    
1. Determine the Code
A. Connect Cat® ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Turn the keyswitch to the ON position.
C. Determine if a diagnostic trouble code is present.
   
Diagnostic Codes    
Result: A -3 or -4 code is present.
Note which ECM is reporting the active sensor supply code.
Proceed to Test Step 2.
Result: A -21 code is present.
Proceed to Test Step 3.    
2. Check for a Failed Sensor
A. Connect to Cat ET.
B. Turn the keyswitch to the ON position.
C. Disconnect a sensor on the suspect sensor supply circuit.
D. Monitor Cat ET while the sensor is disconnected to see if the active code changes to logged.
E. Connect the suspect sensor to the wiring harness
F. Repeat steps C through E for each sensor on the suspect sensor supply.
   
Failed Sensor    
Result: The suspect sensor supply active code changes to logged when a sensor is unplugged.
Repair: Replace the failed sensor.
Verify that the repair resolved the problem.
Result: The suspect sensor supply active code remains active after all sensors on the sensor supply circuit have been checked.
Repair: A failed wiring harness has been detected. Repair or replace the wiring harness.
Verify that the repair resolved the problem.
   
3. Check the Sensor Suppl