33186 Mercruiser BUSHING, ALTERNATOR TO BRACKET SCREW

Table 1
Diagnostic Codes for the NRS
CDL Code Code Description Comments
3405-5 Engine Exhaust Gas Recirculation Valve Control : Current Below Normal The Electronic Control Module (ECM) detects a low current in the circuit for the NRS actuator solenoid.
3405-6 Engine Exhaust Gas Recirculation Valve Control : Current Above Normal The ECM detects a high current in the circuit for the NRS actuator solenoid.
E1090(2) High Engine Exhaust Gas Recirculation Intake Pressure The ECM detects an abnormally high inlet pressure to the NRS.
E1093(2) Low Engine Exhaust Gas Recirculation Differential Pressure The ECM detects an abnormally low reading from the NRS differential pressure sensor.
E1094(2) High Engine Exhaust Gas Recirculation Differential Pressure The ECM detects an abnormally high reading from the NRS differential pressure sensor.
E1095(1) Low Engine Exhaust Gas Recirculation Flow Rate The ECM has detected a low flow rate through the NRS.
E1095(2) Low Engine Exhaust Gas Recirculation Flow Rate The ECM has detected a low flow rate through the NRS.
E1096(1) High Engine Exhaust Gas Recirculation Flow Rate The ECM has detected a high flow rate through the NRS.
E1096(2) High Engine Exhaust Gas Recirculation Flow Rate The ECM has detected a high flow rate through the NRS.
Illustration 1 g02138942
Location of the NRS actuator solenoid
Note: Exhaust Gas Recirculation (EGR) is a term used to describe the recirculation of exhaust gas through the engine as a means to reduce "NOx" emissions. Caterpillar has elected to refer to this system as the NOX Reduction System (NRS). Diagnostic codes are regulated by SAE. The diagnostic codes will reflect the EGR nomenclature.
Illustration 2 g02138941
Schematic for the NRS actuator solenoid
Test Step 1. PERFORM PRESSURE SENSOR CALIBRATION
Connect Cat ET to the service tool connector.
Turn the keyswitch to the ON position. Allow 30 seconds for a calibration of the engine pressure sensors to be performed by the ECM.
Check for diagnostic trouble codes that are associated with the sensor calibration.Check for the following codes:
1785-13 Intake Manifold Pressure Sensor : Calibration Required
3387-13 Engine Exhaust Gas Recirculation Differential Pressure Sensor : Calibration Required
Turn the keyswitch to the OFF position.Results:
No Active -13 Codes - There are no active -13 codes currently. Proceed to Test Step 2.
Active 1785-13 or 3387-13 Code - Either a 1785-13, or a 3387-13 is active.Repair: Perform another calibration attempt, follow these instructions closely:
Turn the keyswitch to the OFF position. Allow the keyswitch to remain in the OFF position for ten minutes.
Turn the keyswitch to the ON position. Allow 30 seconds for the ECM to attempt a calibration of the sensor.
Turn the keyswitch to the OFF position. Allow the keyswitch to remain in the OFF position for 30 seconds.Note: Do not use the battery disconnect switch to power-down the ECM. Ensure that the unswitched battery power to the ECM remains on so that the calibration data can be saved to internal memory.
Turn the keyswitch to the ON position. Check for diagnostic trouble codes that are associated with the sensor calibration.Check for the following codes:
1785-13 Intake Manifold Pressure Sensor : Calibration Required
3387-13 Engine Exhaust Gas Recirculation Differential Pressure Sensor : Calibration RequiredIf the original code is still active, replace the appropriate sensor. Check for the recurrence of the diagnostic codes to verify that the problem is resolved.STOPTest Step 2. CHECK FOR ASSOCIATED CODES
Establish communication between Caterpillar Electronic Technician (ET) and the engine ECM. Refer to Troubleshooting, "Electronic Service Tools" for details.
Download the "Product Summary Report" from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.
Determine if an associated code is active or logged. Table 2 lists the associated diagnostic code.
Table 2
Associated Code
CDL Code WCI
E1092 (2) Expected Result:There are no associated codes that are active or logged.Results:
OK - No associated codes are active or logged. Proceed to Test Step 3.
Not OK - There are associated codes that are active or logged.Repair: Troubleshoot associated codes prior to continuing with this procedure. Refer to Troubleshooting, "Event Codes" to troubleshoot the associated diagnostic code.STOPTest Step 3. CHECK FOR ACTIVE DIAGNOSTIC TROUBLE CODES
Establish a connection between the engine ECM and Cat ET.
Turn the keyswitch to the ON position.
Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.Note: Allow 30 seconds for the codes to become active.Check for the following codes:
3405-5
3405-6
E1090(2)
E1093(2)
E1094(2)
E1095(2)
E1096(1)
E1096(2)Results:
Active 3405-5 - There is a low current in the circuit that is for the solenoid for the valve actuator. Proceed to Test Step 13.
Active 3405-6 - There is a high current in the circuit that is for the solenoid for the valve actuator. Proceed to Test Step 12.
Active or Logged E1090(2) - Proceed to Test Step 6.
Active or Logged E1090(2) and E1095(2) - Proceed to Test Step 6.
Active or Logged E1090(2) and/or E1093(2) and/or E1094(2) - Proceed to Test Step 8.
Active or Logged E1095(2) and/or E1096(2) - Proceed to Test Step 4.Test Step 4. INSPECT ALL EXHAUST PIPING FOR THE NRS FOR LEAKAGE
Illustration 3 g02149542
Inspection points for the exhaust piping for the NRS that is on the top of the engine