C4.4 Marine Generator Set Caterpillar

Speed/Timing - Test

Usage:

C4.4 NRP

This procedure covers the following diagnostic codes:

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Table 1
Diagnostic Trouble Codes for the Speed/Timing Sensors
J1939 Code	Code Description	Comments
190-8	Engine Speed : Abnormal Frequency, Pulse Width, or Period	The Electronic Control Module (ECM) detects the following conditions: An intermittent loss of signal or a complete loss of signal from the primary speed/timing sensor for 2 seconds The engine has been running for more than 3 seconds. 678 diagnostic trouble codes are not active. The warning light will come on and the diagnostic code will be logged. The ECM will use the signal from the secondary speed/timing sensor. The engine will be derated. If the signal from the secondary speed/timing sensor is also lost, the engine will shut down.
723-8	Engine Speed Sensor #2 : Abnormal Frequency, Pulse Width or Period	The Electronic Control Module (ECM) detects the following conditions: A loss of signal from the secondary speed/timing sensor for 2 seconds while the signal from the primary speed/timing sensor remained valid The engine has been running for more than 3 seconds. 678 diagnostic trouble codes are not active. The warning lamp will come on and the diagnostic code will be logged. The loss of signal from the secondary speed/timing sensor will prevent the engine from starting.
637-11	Engine Timing Sensor - Other Failure Mode	The Electronic Control Module (ECM) detects the following conditions: The outputs from the primary speed/timing sensor and the secondary speed/timing sensor differ by more than 8 degrees of crankshaft rotation. The engine has been running for more than 5 seconds. Diagnostic code 190-8 is not active. 678 diagnostic codes are not active. The warning light will come on. This code will not be logged.
Follow the troubleshooting procedure in order to identify the root cause of the fault.

Use this procedure when the engine will not start and the electronic service tool indicates a faulty sensor by displaying "Not Detected" against the faulty sensor on the "No Start Parameter" screen.

The engine uses two engine speed/timing sensors. The primary speed/timing sensor is located on the left-hand side of the cylinder block close to the flywheel housing. The primary speed/timing sensor generates a signal by detecting the movement of the teeth that are located on the crankshaft timing ring. The signal that is generated by the speed/timing sensor is transmitted to the ECM. The ECM uses the signal from the speed/timing sensor to calculate the position of the crankshaft. The signal is also used to determine the engine speed.

The secondary speed/timing sensor is located on the right-hand side of the cylinder block toward the rear of the engine. The secondary speed/timing sensor generates a signal that is related to the camshaft position. The secondary speed/timing sensor detects the movement of the teeth on the timing ring for the camshaft. The signal that is generated by the speed/timing sensor is transmitted to the ECM. The ECM calculates the speed and the rotational position of the engine by using the signal. The secondary speed/timing sensor is required for starting purposes.

During normal operation, the secondary speed/timing sensor is used to determine the cycle that the engine is on. When the timing has been established, the primary speed/timing sensor is then used to determine the engine speed and the angular position.

The loss of signal to the primary sensor and/or the secondary sensor will result in one of the following faults:

The engine will continue to run when only one sensor signal is present from either the primary sensor or the secondary sensor.
Loss of signal both sensors during operation of the engine will cause fuel injection to be terminated and the engine will stop.

The primary sensor and the secondary sensor are interchangeable components. If a sensor is suspect, the sensors can be exchanged in order to eliminate a fault. If a secondary sensor is suspect and a replacement secondary sensor is not available, then the primary sensor and the secondary sensor can be exchanged. This exchange will allow testing to determine if the secondary sensor is faulty.

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Illustration 1	g03609079
Schematic for the speed/timing sensors

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Illustration 2	g03609096
View of the pin locations for the speed/timing sensor on the P2 connector (44) 8 VDC supply for the speed/timing sensor (38) Signal for the primary speed/timing sensor (39) Signal for the secondary speed/timing sensor

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Illustration 3	g03609098
View of the sensor locations on the engine (1) Primary speed/timing sensor (2) Secondary speed/timing sensor

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Illustration 4	g03379946
Typical example of a speed/timing sensor (1) 8 VDC Supply (2) Signal

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Table 2
Troubleshooting Test Steps	Values	Results
1. Inspect Electrical Connectors and Wiring A. Turn the isolator switch to the OFF position. B. Inspect the connectors for the speed/timing sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect". C. Perform a 45 N (10 lb) pull test on each of the wires in the suspect sensor connector and the sensor connections at the ECM. D. Check the screw for the ECM connector for the correct torque of 6 N·m (53 lb in). E. Check the ground connection on the ECM for abrasions and pinch points. F. Check the harness for abrasion and pinch points from the suspect sensor to the ECM. G. Check that the suspect sensor is installed correctly. Check that the suspect sensor is fully seated into the engine.	Loose connection or damaged wire	Result: There is a fault in a connector or the wiring. Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points. Proceed to Test Step 2.
2. Check For Active Diagnostic Codes A. Turn the isolator switch to the OFF position. B. Connect the electronic service tool to the diagnostic connector. C. Turn the isolator switch to the ON position. If the engine will start, then run the engine. D. Use the electronic service tool in order to monitor active diagnostic codes or recently logged diagnostic codes. E. Turn the isolator switch to the OFF position.	Diagnostic codes	Result: There are no active diagnostic codes for the pressure sensors. If there are logged diagnostic codes for the pressure sensors, the fault may be intermittent. Refer to Troubleshooting, "Electrical Connectors - Inspect" in order to identify intermittent faults. Result: There is an active 637-11 diagnostic code. Proceed to Test Step 3. Result: There is an active 190-8 or 723-8 diagnostic code. Proceed to Test Step 5.
3. Inspect the Sensors A. Ensure that the speed/timing sensors are correctly seated in the cylinder block and that the retaining bolts are tightened to a torque of 22 N·m (16 lb ft). Ensure that the speed/timing sensors are not damaged. Replace any damaged sensors. Refer to Disassembly and Assembly, "Crankshaft Position Sensor - Remove and Install" or refer to Disassembly and Assembly, "Camshaft Position Sensor - Remove and Install". B. Turn the isolator switch to the ON position. If the engine will run, then run the engine. C. Use the electronic service tool to check if the 637-11 diagnostic code is still active.	Diagnostic codes	Result: A 637-11 diagnostic code is no longer active. Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service. Result: A 637-11 diagnostic code is still active. Proceed to Test Step 4.
4. Check the Crankshaft Timing Ring and the Timing Ring on the Camshaft A. Remove the primary speed/timing sensor and the secondary speed/timing sensor. Refer to Disassembly and Assembly, "Crankshaft Position Sensor - Remove and Install" or refer to Disassembly and Assembly, "Camshaft Position Sensor - Remove and Install". B. Use a flashlight in order to check the timing ring on the camshaft through the camshaft timing hole for damage. C. Use a flashlight in order to check the crankshaft timing ring for damaged teeth or missing teeth. Ensure that the crankshaft timing ring has not been displaced from the crankshaft.	Loose timing ring or damaged timing segments	Result: Found fault with the crankshaft timing ring or timing ring on the camshaft. If necessary, replace the camshaft. Refer to Disassembly and Assembly, "Camshaft - Remove and Install". If necessary, replace the crankshaft timing ring. Refer to Disassembly and Assembly, "Crankshaft Timing Ring - Remove and Install". Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair has eliminated the fault. Result: No faults found. Repeat this procedure from Test Step 3.
5. Measure the Supply Voltage at the Sensor Connector A. Turn the isolator switch to the OFF position. B. Disconnect the speed/timing sensor with the active diagnostic code. C. Turn the isolator switch to the ON position. D. Measure the voltage from terminal 1 on the sensor connector to engine ground.	7.5 VDC to 8.5 VDC	Result: The sensor supply voltage is not within the expected range - The fault is in the sensor supply wiring between the sensor and the ECM. Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The sensor supply voltage is correct. Proceed to Test Step 6.
6. Exchange the Sensors A. Turn the isolator switch to the OFF position. B. Exchange the primary speed/timing sensor with the secondary speed/timing sensor. Refer to Disassembly and Assembly, "Crankshaft Position Sensor - Remove and Install" and refer to Disassembly and Assembly, "Camshaft Position Sensor - Remove and Install". C. Turn the isolator switch to the ON position. D. Start the engine. E. Use the electronic service tool to check for active diagnostic codes. Wait for 30 seconds in order for diagnostic codes to become active.	A 190-8 diagnostic code was previously active. A 723-8 diagnostic code is now active. OR A 723-8 diagnostic code was previously active. A 190-8 diagnostic code is now active.	Result: The active diagnostic code is now for the other speed/timing sensor. Install a replacement sensor. Refer to Disassembly and Assembly, "Crankshaft Position Sensor - Remove and Install" or refer to Disassembly and Assembly, "Camshaft Position Sensor - Remove and Install". Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The diagnostic code that was previously active is still active. Proceed to Test Step 7.
7. Check the Signal Wire for an Open Circuit A. Turn the isolator switch to the OFF position. B. Disconnect the P2 connector. Disconnect the connector for the suspect speed/timing sensor. C. Use a multimeter to check the resistance between terminal 2 on the harness connector for the sensor and the appropriate terminal on the P2 connector. Refer to Illustration 1.	Less than two Ohms	Result: The resistance is greater than two Ohms - There is an open circuit or high resistance in the signal wire. Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: The resistance is greater than two Ohms. Proceed to Test Step 8.
8. Check the Signal Wire for a Short Circuit A. Turn the isolator switch to the OFF position. B. Disconnect the P2 connector. Disconnect the connector for the suspect speed/timing sensor. C. Use a multimeter to check the resistance between the suspect sensor signal terminal on the P2 connector and all other terminals on the P2 connector. Refer to Illustration 1.	Greater than 100 Ohms	Result: At least one of the resistance measurements is less than 100 Ohms - The fault is in the sensor signal wiring. Repair the faulty wiring or replace the faulty wiring. Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault. Result: All resistance measurements are greater than 100 Ohms. Proceed to Test Step 9.
9. Check if a Replacement ECM Eliminates the Fault A. Make sure that the latest flash file for the application is installed in the ECM. Refer to Troubleshooting, "Flash Programming". B. Contact the Technical Communicator at a Cat dealer. Note: This consultation can greatly reduce the repair time. C. If the Technical Communicator recommends the use of a test ECM, install a test ECM. Refer to Troubleshooting, "Replacing the ECM". D. Turn the isolator switch to the ON position. Use the electronic service tool to verify that the repair eliminates the fault.	Fault eliminated	Result: The fault is eliminated with the test ECM. Reconnect the suspect ECM. If the fault returns with the suspect ECM, permanently install the replacement ECM. Result: The fault is still present with the replacement ECM. Do not use the replacement ECM. Contact the Technical Communicator at a Cat dealer.