KIT-SEAL 3176058 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the secondary (crankshaft) engine speed/timing sensor. Also, use this procedure if any one of the diagnostic codes in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
190-8 Engine Speed: Abnormal Frequency, Pulse Width or Period The Electronic Control Module (ECM) detects an intermittent loss or complete loss of the signal from the speed/timing sensor.
The engine control switch has been in the RUN position for at least 3 seconds. The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
637-11 Engine Timing Sensor : Other Failure Mode The engine has failed the automatic timing calibration during engine start-up. The value of the timing offset that has been stored in memory will be used. This value will continue to be used for the timing calibration until the diagnostic is resolved.
The code is logged.
678-3 ECU 8 Volts DC Supply : Voltage Above Normal The 8 V sensor supply voltage has risen above 8.8 V for 1.5 seconds.
The engine control switch has been in the RUN position for at least 3 seconds. The 190-8 diagnostic code is suppressed while this code is active.
The code is logged.
The amber warning lamp is illuminated.
The service tool displays "Error Indicator" on the status screen for this parameter.
678-4 ECU 8 Volts DC Supply : Voltage Below Normal The 8 V sensor supply voltage has dropped below 7.2 V for 1.5 seconds.
The engine control switch has been in the RUN position for at least 3 seconds. The 190-8 diagnostic code is suppressed while this code is active.
The code is logged.
The amber warning lamp is illuminated.
The service tool displays "Error Indicator" on the status screen for this parameter. This engine utilizes two speed/timing sensors to detect the speed and the timing for the engine. The primary (camshaft) speed/timing sensor is used to detect engine speed and camshaft position during engine starting and also while the engine is running. The secondary (crankshaft) speed timing sensor is used only during engine cranking in order to determine top center of the No. 1 cylinder. Use this procedure to troubleshoot electrical problems with the circuit for the secondary (crankshaft) engine speed/timing sensor. For information related to troubleshooting the primary engine speed/timing sensor, refer to Troubleshooting, "Speed/Timing (Primary) - Test".
Illustration 1 g02644459
Features machined into the flywheel for speed/timing detection
The secondary engine speed timing sensor utilizes a series of holes that are machined into the outer surface of the flywheel to establish a signal. The pattern of