DRIVE AS-MOTOR 4N4517 - Caterpillar

System Operation Description:The engine speed sensor provides the engine speed information to the ECM. The sensor magnetically detects the teeth on the flywheel ring gear. The ECM will not allow the engine to start until the ECM senses a valid engine speed signal.Engine speed is determined by the frequency of the output signal. The signal frequency should be between 0 and 5 kHz.
Illustration 1 g01637404
Illustration 2 g01637405
(10) +8 VDC (18) Engine speed (35) Analog return
Table 1
Diagnostic Code    
Code and Description    Flash Code    Default Conditions which Generate this Code    System Response    
190 -00 Engine Speed Sensor : High     35     The ECM detects a engine speed more than 2450 rpm.     The diagnostic code is logged. Also, the shutdown solenoid will de-energize until the engine speed is below 2420 rpm.    
190-02 Engine Speed Sensor : Erratic, Intermittent, or Incorrect     34     The ECM detects the loss of the primary engine speed signal.     The diagnostic code is active and logged.    
190-08 Engine Speed Sensor : Abnormal Frequency, Pulse Width, or Period     33     The engine speed is changing at a abnormal rate.     The diagnostic code is active and logged.    
190-10 Engine Speed Sensor : Abnormal Rate of Change     34     The engine speed is greater than 3000 rpm. This is due to noise or other conditions.     The diagnostic code is active and logged. Also, the shutdown solenoid will de-energize until the engine speed is below 2420 rpm.    Test Step 1. Inspect Electrical Connectors and Wiring
Turn the engine control switch to the OFF position.
Thoroughly inspect the J14/P14 connector, and the J10/P10 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the engine speed sensor.
Check the allen head screw on each ECM connector for the proper torque. Refer to service Troubleshooting, "Electrical Connectors - Inspect".
Check the harness for abrasions and for pinch points from the battery to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points. Proceed to Test Step 2.
NOT OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check Engine Speed On Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector.
Turn the engine control switch to the ON position.
Attempt to start the engine.
Observe the engine speed on Cat ET.
Turn the engine control switch to the OFF position.Note: Battery voltage may drop below the required level during cranking. If the engine will not start, Cat ET may