0343548 JOHNSON GASKET, Bowl

Table 1
Diagnostic Codes Table    
Code and Description     Conditions which Generate this Code     System Response    
548-5 Throttle Lock Lamp current below normal     The Electronic Control Module (ECM) detects current that is below normal.     The code is logged.    
548-6 Throttle Lock Lamp current above normal     The ECM detects current that is above normal.     The code is logged.    The indicator lamps are located in the dash display.The ECM illuminates the throttle lock lamp and the starting aid lamp for a brief period after the keyswitch is placed in the ON position in order to run diagnostics on the lamp circuits. This also provides a visual check of the lamp's operation.The throttle lock feature is disabled by the ECM if either of the diagnostic codes for the throttle lock lamp are active.
Illustration 1 g01399067
Schematic for the engine's lamp circuitsTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Illustration 2 g01139425
ECM (1) J1/P1 connectors (2) J2/P2 connectors
Thoroughly inspect the J1/P1 and thoroughly inspect the J2/P2 ECM connectors. Thoroughly inspect any connectors that are associated with the lamp circuits. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01398637
P1 ECM connector (P1-28) Start aid indicator (P1-22) Throttle lock lamp
Perform a 45 N (10 lb) pull test on each of the wires for the lamp circuits.
Check the torque of the allen head screw on the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the dash display back to the ECM.Expected Result:All of the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and connectors appear to be in good repair. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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. Inspect the Lamp and the Lamp Socket
Remove the lamp assembly for the suspect lamp from the dash display.
Measure the resistance of the lamp assembly across the terminals of the lamp socket.Expected Result:The measurement across the terminals of the lamp assembly does not indicate an open circuit.Results:
OK - The resistance measurement did not indicate an open circuit. The lamp assembly is not the cause of the problem. Proceed to Test Step 3.
Not OK - An open circuit was detected across the terminals of the lamp assembly.Repair: The lamp or the lamp socket is the cause of the problem. If necessary, replace the lamp or the lamp socket. Verify that the repair resolves the original problem.STOPTest Step 3. Check the Ground Circuit at the Dash Display
Ensure that the lamp assembly is removed from the dash display.
At the dash display, measure the resistance from the ground terminal for the lamp to ground.Expected Result:The measurement does not indicate an open in the ground circuit.Results:
OK - The measurement does not indicate an open in the ground circuit. The circuit between the dash display and the chassis ground is OK. Install the lamp assembly into the lamp socket. Do not install dash display at this time. Proceed to Test Step 4.
Not OK - The measurement indicates an open in the ground circuit.Repair: There is a poor connection between the lamp and chassis ground. Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the connector seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.STOPTest Step 4. Check the Harness for an Open Circuit at the ECM Connector
Disconnect the J1/P1 connector from the ECM.
Measure the resistance between the terminal for the suspect lamp circuit and chassis ground.Expected Result:An open circuit condition does not exist in the harness.Results:
OK - The lamp circuit does not have an open circuit in the harness. Proceed to Test Step 5.
Not OK - At least one of the circuits indicated an open circuit condition.Repair: There is an open circuit in a harness or a connector. Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the connector seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.STOPTest Step 5. Check the Harness for a Short Circuit at the ECM Connector
Remove electrical power from the ECM.
Remove the lamp from the lamp assembly for the suspect lamp circuit.
Disconnect connectors J1/P1 and J2/P2 from the ECM.
Measure the resistance between the terminal for the suspect lamp circuit and all of the other terminals on the J1/P1 and the J2/P2 ECM connectors. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Measure the resistance between the terminal for the suspect lamp circuit and chassis ground. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Install the lamp into the lamp assembly. Restore the dash display to the original configuration. Connect the J2/P2 ECM connectors.Expected Result:Each resistance measurement indicates an open circuit.Results:
OK - Each measurement indicates an open circuit. The circuit appears to be OK. Proceed to Test Step 6.
Not OK - A measurement does not indicate an open circuit. There is a short circuit in the harness or in the connectors between the ECM and the throttle lock lamp.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the connector seals are properly in place and ensure that the connectors are completely coupled. Refer to the electrical schematic for information that relates to the machine wiring harness. Verify that the repair eliminates the problem.STOPTest Step 6. Check the Operation of the ECM
Connect a voltage test lamp at the terminal of the suspect lamp circuit at the ECM connector.
Remove the wire from the terminal for the suspect lamp circuit on the J1/P1 ECM