TUBE ASSEM. 9K8183 - Caterpillar

System Operation Description:The Electronic Control Module (ECM) provides the Engine Speed/Timing Sensor with 13 1.0 VDC. The Engine Speed/Timing Sensors provide a pulse signal to the ECM. The signal is created as the timing reference gear rotates past the pickup of the Engine Speed/Timing Sensor. The timing reference gear is mounted on the rear of the left camshaft. A unique tooth pattern on the timing reference gear allows the ECM to determine the crankshaft position, engine rotation, and engine rpm.If the Primary Engine Speed/Timing Sensor fails, the ECM will use the Secondary Engine Speed/Timing Sensor until electrical power is removed from the ECM. To prevent any unnecessary down time, the primary sensor should be repaired or replaced at the earliest possible convenience.The Engine Speed/Timing Sensor generates a pulse signal to the Electronic Control Module (ECM) as each tooth passes the sensor. The ECM counts the pulses in order to determine the engine rpm. The ECM memorizes the pattern of the pulses. The ECM compares that pattern to a standard pattern in order to determine the crankshaft position. The ECM uses this information to determine the No. 1 cylinder. The ECM then triggers each unit injector to fire in the correct firing order and at the correct time. The actual timing and duration of each injection is determined by the ECM. The ECM uses engine rpm and engine load to determine the timing and duration of injection. The loss of the timing signal from the Engine Speed/Timing Sensor generates an alert on the ET status screen. The loss of the timing signal from the Engine Speed/Timing Sensor triggers the termination of the signals to the fuel injectors.Note: If the ring gear is reversed, the diagnostic codes 190-08 and 342-08 will be generated and the ECM will not fire the injectors.
Illustration 1 g00820920
Test Step 1. Check for Active Diagnostic Codes.
Connect the ET at the Service Tool Connector.
Turn the Battery switch for the ECM to the ON position.
Monitor the active diagnostic codes on the ET.Expected Result:Any of the following diagnostic codes are active:
CID-FMI 190-02 Loss of Engine Speed signal
CID-FMI 190-03 Engine Speed open/short to +batt
CID-FMI 190-07 Primary Speed Sensor misinstalled
CID-FMI 342-02 Loss of Secondary Engine Speed signal
CID-FMI 342-07 Secondary Speed Sensor misinstalled
CID-FMI 342-03 Secondary Engine Speed open/short to +battResults:
OK - Either a CID-FMI 190-03 Engine Speed open/short to +batt diagnostic code or a CID-FMI 342-03 Secondary Engine Speed open/short to +batt diagnostic code is active. Proceed to test step 2.
OK - A CID-FMI 190-07 Primary Speed Sensor misinstalled diagnostic code and a CID-FMI 342-07 Secondary Speed Sensor misinstalled are active.Repair: Switch the primary engine speed/timing sensor and the secondary engine speed/timing sensor. Verify that the problem is no longer present.STOP
OK - A CID-FMI 190-02 Loss of Engine Speed signal or a CID-FMI 342-02 Loss of Secondary Engine Speed signal diagnostic code is present. Proceed to test step 5.Test Step 2. Check the Electrical Connectors and the Wiring.
Turn the Battery switch for the ECM to the OFF position.
Thoroughly inspect the ECM connector