880814 Mercury CAP

Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions that Generate this Code System Response
678-3 ECU 8 Volts DC Supply : Voltage Above Normal This power supply is not used for this application. The code is logged.
678-4 ECU 8 Volts DC Supply : Voltage Below Normal
3358-21 Engine Exhaust Gas Recirculation Inlet Pressure : Data Drifted Low The Electronic Control Module (ECM) detects no 5 VDC supply to the Nox Reduction System (NRS) absolute pressure sensor. The code is logged.
3509-3 5 Volt Sensor DC Power Supply : Voltage Above Normal This code indicates that the voltage of the sensor supply is above normal. During normal engine operation, the supply voltage must not exceed 5.16 V. The code is logged.
All affected sensors are set to default values.
3509-4 5 Volt Sensor DC Power Supply : Voltage Below Normal This code indicates that the voltage of the 5 V supply is below normal. During normal engine operation, the 5 V supply must not drop below 4.84 V. The code is logged.
All affected sensors are set to default values.
3510-3 Sensor Supply Voltage 2 : Voltage Above Normal This code indicates that the voltage of sensor supply 2 is above normal. During normal engine operation, the supply voltage must not exceed 5.16 V. The code is logged.
All affected sensors are set to default values.
3510-4 Sensor Supply Voltage 2 : Voltage Below Normal This code indicates that the voltage of the 5 V supply is below normal. During normal engine operation, the 5 V supply must not drop below 4.84 V. The code is logged.
All affected sensors are set to default values.
3563-21 Engine Intake Manifold #1 Absolute Pressure : Data Drifted Low The ECM detects no 5 V supply to the intake manifold pressure sensor. The code is logged.
5580-21 Fuel Pressure Sensor - After Fuel Filter : Data Drifted Low The ECM detects no 5 V supply to the intake manifold pressure sensor. The code is logged. System OperationThe ECM supplies a regulated voltage of 5.0 0.2 V to the following sensors:
Engine oil pressure sensor
Barometric pressure sensor
Crankcase pressure sensor
Intake manifold pressure sensor
NRS absolute pressure sensor
Fuel pressure sensor after the filter
NRS delta pressure sensor
Engine oil temperatureThe 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 -21 code becomes active when the ECM determines that the 5 V supply is missing at the pressure sensor. The ECM sets the value of the suspect sensor to the default value.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 three diagnostic codes are active, one of the sensors may be 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 g02175025
Schematic for the 5 V sensors
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g02175404
Location of the ECM connectors (left side engine view)
(1) J1/P1 ECM connectors
(2) J2/P2 ECM connectors
Thoroughly inspect connectors (1) and (2). Inspect all of the connectors that are associated with the sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g02161457
Terminal locations at the P2 ECM connector for the analog sensor supplies
(P2-30) Sensor return
(P2-72) +5 V supply
(P2-81) +5 V supply
(P2-83) Sensor return
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connectors that are associated with the circuit.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasion and for pinch points from the sensors back to the ECM. Expected Result:All connectors, pins, and sockets are coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Diagnostic Codes that are Active or Logged
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
Monitor the active diagnostic code screen on Cat ET. Check and record any diagnostic codes that are active or logged. Look for the following diagnostic codes:
678-3
678-4
3358-21
3509-3
3509-4
3510-3
3510-4
3563-21
5580-21 Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Remove the electrical power from the ECM. Expected Result:No diagnostic codes are active or logged.Results:
OK - No diagnostic codes are active or logged.Repair: There does not appear to be an electrical problem with the sensor supply at this time. If the problem is intermittent, refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
678-3 or 678-4 Active or Logged - Either the 678-3 or 678-4 diagnostic code is active or logged at this time. There is an electrical problem with the digital sensor supply. Proceed to Test Step 6.
3358-21, 3563-21, or 5580-21 Logged - A -21 diagnostic code is logged at this time. The analog supply is not reaching the sensor or there is a problem with the sensor. Proceed to Test Step 3.
3510-3 or 3510-4 Active or Logged - Either the 3510-3 or 3510-4 diagnostic code is active or logged at this time. There is an electrical problem with the +5 V sensor supply. Proceed to Test Step 4.Test Step 3. Check the Supply Voltage at the Sensor Connector
Disconnect the harness connectors for the following sensors:
Barometric pressure sensor
Crankcase pressure sensor
Engine oil pressure sensor
Fuel pressure sensor (filtered fuel pressure)
Intake manifold pressure sensor
NRS absolute pressure sensor
NRS differential pressure sensor
Restore the electrical power to