GEAR (16 TEETH) 4K4277 - Caterpillar

STEP 1. Check Rack Position Sensor Calibration Test Procedure:Verify Rack Position Sensor Calibration using Service Procedure D. Expected Results:Rack sensor is properly calibrated. STEP 2. Check Rack Position Sensor Supply Voltage Test Procedure:Disconnect the Rack Position Sensor from the engine wiring harness. At the harness side of the connector, measure the DC voltage between pins 1 and 2. Expected Results:Voltage is between 12 VDC and 25 VDC. STEP 3. Check Engine Performance Test Procedure:Cycle the engine back and forth between a high notch and idle several times while observing the diagnostic lamps at the Locomotive Control box. Expected Results:The diagnostic lamps continue to display the rack position sensor fault. (If other faults are displayed, the rack position sensor fault continues to be displayed at its allotted time.) The engine speed is not erratic. Acceleration and deceleration are smooth. The engine picks up load smoothly. STEP 4. Check Wiring Harness Between Rack Sensor and Control Box Test Procedure:Shutdown engine. Disconnect Rack Position Sensor from engine wiring harness. Disconnect Connector J2 from box. Place a jumper wire between harness connector J2 pins 3 and 4. Measure the resistance between pins 1 and 3 of the rack position sensor connector at the wiring harness. Expected Results:The resistance measured is less than 5 ohms. STEP 5. Check Sensor Ground Wire Test Procedure:Remove jumper wire from connector J2 pins 3 and 4. Connect jumper wire between connector J2 pins 4 and 5. Measure the resistance between pins 2 and 3 of the rack sensor connector at the wiring harness. Expected Results:The resistance measured is less than 5 ohms. STEP 6. Check Harness for Short Circuits Test Procedure:Remove jumper wire from connector J2 pins 4 and 5. Check for short circuits between the harness side rack position sensor connector pins and other harness wires. Expected Results:There are no short circuits in the wiring harness. STEP 7. Manual Linkage Check Test Procedure:With engine stopped, manually move actuator lever and linkage to full FUEL ON position against stop screw. Expected Results:Linkage should move through full travel until it is against stop screw without binding or excessive force. STEP 8. Resistance Check of Actuator and Leads Test Procedure:Remove Connector J2 from Control Box. Measure the resistance between J2 pins 1 and 2 at the wiring harness. Expected Results:Measured resistance should be between 30 and 40 ohms. STEP 9. Actuator Coil Resistance Check Test Procedure:Disconnect wiring connector from actuator. Put a jumper across pins C and D of connector. Measure the actuator coil resistance across connector pins A and B. (See Service Procedure B fig. 2.) If sure-seal connector is not used and wire connection is crimped, the wires will have to be cut. Cut the wire at each side of the crimp connection to remove a potential problem. Expected Results:Measured resistance to be between 30 to 40 ohms. STEP 10. Actuator Lead Resistance Check Test Procedure:Measure resistance of each lead between: Pin A and J2 connector pin 1. Pin B and J2 connector pin 2. Expected