809495A 1 Mercury VALVE GUDE REMOVER

Table 1
Diagnostic Codes Table    
Code and Description    Conditions which Generate this Code    System Response    
190-8 Engine Speed Sensor abnormal frequency, pulse width, or period     The engine speed is greater than zero rpm and the pattern from the timing ring is incorrect for five seconds.     The engine speed is set to zero rpm.
The code is active.
The code is logged if the pattern from the timing ring returns for five seconds.    
342-8 Secondary Engine Speed Sensor abnormal frequency, pulse width, or period    The Electronic Control Module (ECM) provides the engine speed/timing sensor with 12 1 VDC. The engine speed/timing sensor provides a pulse signal to the ECM. The signal is created as the timing reference gear rotates past the pickup of the engine speed/timing sensors. 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, rotation, and 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. In order to prevent any unnecessary down time, the primary engine speed/timing sensor should be repaired or replaced at the earliest possible convenience.The engine speed/timing sensor generates a pulse signal to the ECM as each tooth of the timing reference gear 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 position of the No. 1 piston. The ECM then triggers each fuel 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 signal from the engine speed/timing sensor generates a diagnostic code. The loss of the signals from both of the engine speed/timing sensors triggers the termination of the signals to the fuel injectors.
Illustration 1 g01265854
Schematic for the engine speed/timing sensors and the timing calibration sensorTest Step 1. Inspect Electrical Connectors and Wiring
Turn the switch that provides power to the keyswitch input for the ECM to the OFF position.
Turn the breaker for the ECM to the OFF position.
Illustration 2 g01228838
Location of the J1/P1 ECM connectors (typical front side engine view) (1) J1/P1 ECM connectors
Illustration 3 g01215178
Location of the engine speed/timing sensors (typical left side engine view) (2) Primary engine speed/timing sensor (3) Secondary engine speed/timing sensor
Illustration 4 g01228794
Location of the timing calibration probe (typical right side engine view) (4) Timing calibration sensor
Thoroughly inspect connectors (1). Also, thoroughly inspect the connectors for sensors (2), (3), and (4). Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Illustration 5 g01265855
P1 ECM connector (P1-13) Secondary engine speed/timing signal (P1-33) Primary engine speed/timing signal (P1-40) Engine timing calibration − (P1-41) Engine timing calibration + (P1-43) +12 V supply (P1-51) Digital return
Illustration 6 g01159881
Sensor connector (Terminal A) Sensor supply (Terminal B) Sensor return (Terminal C) Signal
Perform a 45 N (10 lb) pull test on each wire in the ECM connector and the sensor connectors that are associated with the circuit.
Check the allen head screw at each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for "ACTIVE" Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the breaker for the ECM to the ON position.
Turn the switch that provides power to the keyswitch input for the ECM to the ON position.
Check the diagnostic codes on Cat ET.
Turn the switch that provides power to the keyswitch input for the ECM to the OFF position.
Turn the breaker for the ECM to the OFF position.Expected Result:No diagnostic codes are active.Results:
OK - The 190-8 diagnostic code or the 342-8 diagnostic code is not active.Repair: There may be an intermittent problem in the circuit. If an intermittent problem is suspected, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The 190-8 diagnostic code or the 342-8 diagnostic code is active. Proceed to Test Step 3.Test Step 3. Inspect the Engine Speed/Timing Sensor
Remove the suspect engine speed/timing sensor.
Inspect the sensor tip for damage.Expected Result:The center of the tip of the engine speed/timing sensor is free of damage.Results:
OK - The engine speed/timing sensor is undamaged. Reinstall the sensor. Proceed to Test Step 4.
Not OK - The engine speed/timing sensor is damaged.Repair: Replace the engine