0393088 JOHNSON FUEL PUMP REPAIR KIT

The engine uses two engine speed sensors. The primary speed sensor is located on the left-hand side of the front housing. The primary speed sensor generates a signal by detecting the movement of the teeth that are located on the crankshaft gear. The signal that is generated by the speed sensor is transmitted to the ECM. The ECM uses the signal from the speed sensor to calculate the engine speed. The secondary speed sensor is located in the right of the front cover. The secondary speed sensor generates a signal that is related to the camshaft speed. The secondary speed sensor detects the movement of the camshaft gear. The signal that is generated by the speed sensor is transmitted to the ECM. The ECM calculates the speed of the engine by using the signal.The loss of signal to the primary sensor and/or the secondary sensor will result in one of the following faults:
The engine will be derated when only one sensor signal is present from either the primary sensor or the secondary sensor.
Loss of signal from the primary sensor and the secondary sensor during operation of the engine will cause the engine to be shut down.Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the primary and secondary speed sensor signal wire. This pull-up voltage is required for correct sensor operation and diagnostics.
Illustration 1 g03694593
Schematic for the speed sensors
Illustration 2 g03259416
View of the pin locations for the speed sensors on the P2 connector
(8) Primary speed sensor ground
(9) Primary speed sensor signal
(10) Primary speed sensor 5 VDC supply
(11) Secondary speed sensor 5 VDC supply
(12) Secondary speed sensor signal
(13) Secondary speed sensor ground
Illustration 3 g03259421
Typical example of speed sensor
(1) Speed sensor 5 VDC supply
(2) Speed sensor ground
(3) Speed sensor signal
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the terminal connections on the P2/J2 ECM connectors.
B. Inspect the connectors for the speed 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 harness for abrasion and pinch points from the suspect sensor to the ECM.
E. Check that the suspect sensor is installed correctly. Check that the suspect sensor is fully seated into the engine. Check that the sensor is securely latched.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are correctly connected.
If the primary speed sensor must be replaced or the sensor must be reinstalled, refer to Disassembly and Assembly, "Crankshaft Position Sensor - Remove and Install". If the secondary speed sensor must be replaced or the sensor must be reinstalled, 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: All connectors, pins, and sockets are correctly connected and/or inserted and the harness is free of corrosion, of abrasion and of pinch points. The speed sensors are installed correctly.
Proceed to Test Step 2.
2. Check for Diagnostic Codes
A. Turn the keyswitch to the OFF position.
B. Connect the electronic service tool to the diagnostic connector.
C. Turn the keyswitch to the ON position. If the engine will start, then run the e