F1914 Force HEX HD SCREW, 1/4 - 20 X 3/4

Table 1
Diagnostic Codes Table    
Description    Conditions which Generate this Code    System Response    
3002-2 Engine Exhaust NOx Level Sensor : Erratic, Intermittent, or Incorrect     The Electronic Control Module (ECM) has received a communication that indicates that the data from the NOX sensor is incorrect.     The power to the sensor is turned off.
NOX feedback is turned off.
The fuel correction factor is locked at the last value that is known to be good.
The code is logged.
The alarm output is activated.    
3002-9 Engine Exhaust NOx Level Sensor : Abnormal Update Rate     The ECM has not received several messages that were expected from the NOX sensor over the CAN data link.     NOX feedback is turned off.
The fuel correction factor is locked at the last value that is known to be good.
The code is logged.
The alarm output is activated.    
3002-12 Engine Exhaust NOx Level Sensor : Failure     The ECM has received communications from the NOX sensor that indicates that an internal fault has been detected.     NOX feedback is turned off.
The fuel correction factor is locked at the last value that is known to be good.
The code is logged.
The alarm output is activated.
The shutdown output is activated.
The engine is shut down.    
E717(1) Engine Exhaust NOx Level Sensor Operating Temperature Not Reached     The ECM has not received a communication that is expected from the NOX sensor. The communication reports that the operating temperature of the sensor has been reached.     NOX feedback is turned off.
The fuel correction factor is locked at the last value that is known to be good.
The code is logged.
The alarm output is activated.    The NOX sensor group is used by the ECM to measure the level of NOX concentration in the engine exhaust. This value is reported back to the ECM via the CAN data Link. The ECM uses this information to control the air/fuel ratio for the engine. By controlling the air/fuel ratio, the ECM is able to control the engine operation for optimum performance at reduced exhaust emissions.The NOX sensor group is made up of two separate components:Sensor - The NOX sensor consists of a ceramic element that measures the concentration of NOX in the exhaust gas. The sensor contains a heating element that is used to heat the sensor to approximately 800 °C (1450 °F). Once the heating element reaches this temperature, the sensor begins sending NOX data to the sensor buffer.Sensor buffer - The sensor buffer is used to process the signals that are received from the sensor. The buffer transmits this information to the ECM via the CAN data link. The buffer also reports diagnostic data to the ECM over the CAN data link. The sensor buffer is powered through a Pulse Width Modulated output (PWM output) by the ECM. The sensor buffer requires 18 to 36 V in order to operate.The buffer is powered by the ECM after the following conditions are verified:
No diagnostic codes related to the NOX sensor are active
Engine speed above 500 rpmThe sensor and the sensor buffer are integrated parts. The sensor and the sensor buffer must be replaced as a single component, if necessary.An active diagnostic code is probably caused by a problem with a connector or harness for the CAN data link or the power supply. The next likely cause is a problem with the NOX sensor group. The least likely cause is a problem with the ECM.
Illustration 1 g01592466
Schematic of the circuit for the NOX sensorTest Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control switch to the OFF/RESET position. Remove the electrical power from the engine.
Illustration 2 g01418482
Location of the components for the NOX sensor (typical rear engine view) (1) NOX sensor group
Illustration 3 g01418490
Locations of the connectors for the NOX sensor (typical left side engine view) (2) J2/P2 ECM connectors for the master ECM (3) J1/P1 ECM connectors for the master ECM (4) J8/P8 control harness connectors at the terminal box for the master ECM
Thoroughly inspect the condition of connectors for NOX sensor (1). Also, thoroughly inspect the condition of ECM connectors (2) and (3), and control harness connectors (4). Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 4 g01412137
Terminal connections at the P1 ECM connector that are for the NOX sensor (P1-34) CAN data link − (P1-42) CAN shield (P1-50) CAN data link +
Illustration 5 g01418571
Terminal connections at the P2 ECM connector that are for the NOX sensor (P2-63) PWM output (24 V) (P2-64) Return
Illustration 6 g01418503
Terminal locations at the P8 connector that are for the NOX sensor (P8-h) CAN shield (P8-C) PWM output (24 V) (P8-P) Return (P8-O) CAN data link + (P8-Y) CAN data link −
Illustration 7 g01418510
Terminal locations at the harness connectors that are for the NOX sensor (Terminal 1) PWM input (24 V) (Terminal 2) Return (Terminal 3) CAN Data Link − (Terminal 4) CAN Data Link +
Perform a 45 N (10 lb) pull test on each of the wires in the circuit for the NOX sensor.