INDICATOR-COOL 2243344 - Caterpillar

Use this procedure to troubleshoot the electrical system if a problem is suspected with one or more of the engine speed/timing sensors. Also, use this procedure if one of the following codes is active or easily repeated.
Table 1
J1939 Code and Description Comments
190-8
Engine Speed : Abnormal Frequency, Pulse Width, or Period Code is for the crankshaft sensor.
The ECM has lost the crankshaft sensor signal.
The engine is shutdown.
The code is logged.
190-19
Engine Speed : Data Error Code is for the crankshaft sensor.
The ISM has lost the crankshaft sensor signal.
The engine is shutdown.
The code is logged.
723-8
Engine Speed Sensor #2 : Abnormal Frequency, Pulse Width, or Period Code is for the left camshaft #1
The engine is shutdown.
The code is logged.
4202-8
Engine Speed Sensor #3 : Abnormal Frequency, Pulse Width, or Period Code is for the right camshaft #2
The engine is shutdown.
The code is logged. There are three engine speed timing sensors for the engine:
One is on the crankshaft flywheel housing
One is on the front housing at the left camshaft
One is on the front housing at the right camshaftThe crankshaft sensor detects a hole in the face of the flywheel, to determine crankshaft position.Timing wheels are mounted to the front of both camshafts.The timing wheels have a special tooth pattern and are monitored by the cam sensors.The engine performs a timing calibration automatically, during every startup, based on the speed/timing signals from the crankshaft and the camshafts.The ECM utilizes all three sensors to determine the crankshaft position and engine speed to calculate the next desired ignition signal.If any one of the three sensor signals are lost, the ignition will be disabled.
Illustration 1 g06193607
Table 2
Troubleshooting Test Steps Values Results
1. Check for Active Codes and Logged Codes
A. Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Restore electrical power to the ECM.
C. Start the engine and run the engine until the engine is at normal operating temperature.
Note: If the engine will not start, monitor the engine rpm on Cat ET when the engine is being cranked. If necessary, power Cat ET from another battery when the engine is being cranked.
D. Determine if a code is active or logged.
Codes
Result: A code is not active or logged.
Repair: Refer to the appropriate engine symptom in this Troubleshooting manual.
Result: A 190-08, 723-08,4202-08, or a 190-19 code is active or logged.
Proceed to Test Step 2.
Result: No engine rpm. Cat ET is not reporting engine rpm for at least one engine speed/timing sensor when the engine is cranked.
Proceed to Test Step 3.
2. Check the Installation of the Sensor Assembly
A. Turn the main disconnect switch to the OFF position.
B. Visually inspect the sensors without removing the sensor assembly from the engine.
Verify that the bracket securely holds the flange of the sensor flush against the mounting surface.
Verify that the bracket is not bent. If the bracket is bent or if an obstruction is preventing the sensor assembly from being installed correctly, the engine will not start.
Note: The bracket cannot be replaced separately.
C. Remove the suspect engine speed/timing sensor from