94453 Mercury BUSHING

Illustration 1 g06101475
NRS system for a C4.4 engine
(1) NRS inlet temperature sensor
(2) NRS mixer
(3) Pipe for the NRS differential pressure sensor
(4) Pipe for the NRS inlet pressure sensor
(5) Manifold for the NRS pressure sensors
(6) NRS differential pressure sensor
(7) NRS inlet pressure sensor
Illustration 2 g06101479
NRS system for a C6.6 engine
(1) NRS inlet pressure sensor
(2) NRS outlet pressure sensor
(3) Pipe for the NRS outlet pressure sensor
(4) Pipe for the NRS inlet pressure sensor
(5) NRS mixer
(6) NRS inlet temperature sensorProbable Causes
Diagnostic codes
Electrical connectors and harness
Air inlet and exhaust system
NRS inlet pressure sensor and sensor pipes
NRS temperature sensor
NRS mixerRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 2
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
A. Download the Warranty Report and the Product Status Report with Histograms before performing any troubleshooting or clearing any diagnostic codes.
Note: The downloaded information will be required by the Technical Communicator if troubleshooting assistance is needed.
B. Use the electronic service tool to check for active or logged codes.
Diagnostic codes
Result: A diagnostic code for the NRS valve is active or logged.
Repair: Rectify the NRS valve code. Refer to Troubleshooting, "Motorized Valve - Test".
Result: A 2659-7 code is active.
Proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Harness
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors for the components in the NRS system. Refer to Troubleshooting, "Electrical Connectors - Inspect".
C. Perform a 45 N (10 lb) pull test on each of the wires in any suspect connector and the connections at the ECM.
D. Check that the ground connection on the ECM and the negative terminal on the battery are correctly installed.
E. Check the ground connection on the ECM for abrasions and pinch points.
F. Check the screws for the ECM connector for the correct torque of 6 N m (53 lb in).
G. Check the harness for abrasion and pinch points from the NRS components to the ECM.
H. Check that any suspect connector is installed correctly.
Connectors and harness
Result: An electrical connector or a cable is not correctly installed.
Repair: Install the connector or cable correctly.
Result: The harness is faulty.
Install a replacement harness.
Result: The harness and connectors are OK.
Proceed to Test Step 3.
3. Check the Air Inlet and Exhaust System
A. Check the air inlet system for leaks and for restrictions.
B. Check the exhaust system for leaks and for restrictions.
C. Test the exhaust back pressure regulator. Refer to Troubleshooting, "Motorized Valve - Test".
Air inlet and exhaust system
Result: The air inlet system has a leak or is restricted.
Repair: Clear any restrictions in the air inlet system.
Repair any air leaks in the air inlet system.
Result: The exhaust system has a leak or is restricted.
Repair: Clear any restrictions in the exhaust system.
Repair any air leaks in the exhaust system.
If the fault is still present, proceed to Test Step 4.
4. Check the NRS Inlet Pressure Sensor and Sensor Pipes
For a C4.4 engine, refer to Illustration 1. For a C6.6 engine, refer to Illustration 2.
A. Check pipe (4) for the NRS inlet pressure sensor for leaks, restrictions, or blockage.
B. Check pipe (3) for the NRS differential pressure sensor for leaks or any restriction.
C. Test the exhaust back pressure regulator. Refer to Troubleshooting, "Motorized Valve - Test".
Pressure sensor and pipes
Result: There is a leak, a restriction, or a blockage in one of the sensor pipes.
Repair: If a pipe has a leak or a restriction, replace the pipe.
If a pipe is blocked with soot or condensates, remove the pipe. Use an air line that is set at a maximum pressure of 200 kPa (29 psi) to clear the blockage. If the blockage is cleared, install the pipe. If the blockage cannot be cleared, replace the pipe.
Result: The NRS inlet pressure sensor is blocked.
Repair: Replace the NRS inlet pressure sensor.
Result: There are no leaks, restrictions, or blockages in the sensor or the pipes.
Proceed to Test Step 5.
5. Check the NRS Temperature Sensor
For a C4.4 engine, refer to Illustration 1.
For a C6.6 engine, refer to Illustration 2.
A. Remove temperature sensor (1) from NRS mixer (2). Refer to Disassembly and Assembly, "Temperature Sensor (Cooled Exhaust Gas) - Remove and Install".
B. Check the sensor probe for excessive deposits.
C. Test the exhaust back pressure regulator. Refer to Troubleshooting, "Motorized Valve - Test".
Temperature sensor
Result: The probe on the temperature sensor has excessive deposits.
Repair: Carefully remove the deposits from the sensor probe. Make sure that the sensor probe is not damaged.
If the deposits cannot be easily removed, replace the temperature sensor. Refer to Disassembly and Assembly, "Temperature Sensor (Cooled Exhaust Gas) - Remove and Install".
Result: The probe on the temperature sensor does not have excessive deposits.
Proceed to Test Step 6.
6. Inspect the NRS Mixer
A. Inspect the NRS mixer for cracks, holes, or damage.
NRS mixer
Result: The NRS mixer is defective.
Repair: Replace the NRS mixer. Refer to Disassembly and Assembly, "Inlet Air Control - Remove" and Disassembly and Assembly, "Inlet Air Control - Install".
Result: There are no visible faults on the NRS mixer.
Contact the Dealer Solutions Network (DSN).