803522T 1 Mercury CARBURETOR

Illustration 1 g06114441
Schematic for the injector solenoids
Probable Causes
Codes
Wiring
Open circuit
Short Circuit
ECMRecommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Establish communication between Cat® Electronic Technician (ET) and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
B. Determine if a code is active or logged.
Codes
Result: A code is logged or active.
Proceed to Test Step 2.
Result: A code is not logged or active. There is not an electronic problem with the injectors at this time.
Proceed to Test Step 2.
2. Inspect the Wiring Harness Between the ECM and the Valve Cover Base
A. Turn the keyswitch to OFF.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector. Perform a pull test on each of the wires that are associated with injector solenoids.
D. Check the allen head screw on the ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
E. Check the harness and wiring for abrasions and for pinch points from the valve cover base to the ECM.
Wiring
Result: The connectors and the wiring appear to be OK.
The harness between the ECM and the connector does not have an open circuit.
Proceed to Test Step 3.
Result: 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 coupled. Perform an injector solenoid test in order to verify that the problem has been resolved.
If the problem is not resolved, proceed to Test Step 3.
3. Check the Harness between the ECM and the Valve Cover Base for an Open Circuit
A. Turn the keyswitch to OFF. A strong electrical shock hazard is present if the keyswitch is not turned off.
B. Remove electrical power from the engine ECM.
C. Disconnect the connectors of the injector harness at the valve cover base.
D. Fabricate a jumper wire long enough to create a short circuit on the different terminal locations at the connector of the injector harness. Crimp connector pins on both ends of the jumper wire.
E. Insert one end of the jumper wire into the connector socket for the suspect injectors supply wire. Insert the other end of the jumper wire into the connector socket for the suspect injectors return wire. The jumper wire will bypass the injector solenoid.
F. Restore electrical power to the engine ECM.
G. Turn the keyswitch to ON.
H. Perform the "Injector Solenoid Test" in Cat ET.
I. Repeat this test for each suspect circuit. Stop the "Injector Solenoid Test" before handling the jumper wire. Restore the wiring to the original configuration.
Open circuit
Result: The harness is OK.
Proceed to Test Step 4.
Result: The harness is NOT OK
Repair: Repair the harness or replace the harness between the ECM and the valve cover base. Perform an injector solenoid test in order to verify that the problem is resolved.
If the problem is not resolved, proceed to Test Step 4.
4. Check the Harness between the ECM and the Valve Cover Base for a Short Circuit
A. Turn the keyswitch to OFF. A strong electrical shock hazard is present if the keyswitch is not turned off.
B. Remove electrical power from the engine ECM.
C. Disconnect the connectors of the injector harness at the valve cover base.
D. Restore electrical power to the engine ECM.
E. Turn the keyswitch to ON.
F. Perform the Injector Solenoid Test at least two times.
Short circuit
Result: The harness is OK.
Proceed to Test Step 5.
Result: The harness is NOT OK.
Repair: The problem is in the wiring to the ECM or the ECM is not operating properly. Repair the wiring or replace the wiring to the ECM. Perform an injector solenoid test in order to verify that the problem is resolved.
If the problem is not resolved, proceed to Test Step 8.
5. Inspect the Wiring Harness Between the Valve Cover Base and the Injectors
A. Turn the keyswitch to OFF. A strong electrical shock hazard is present if the keyswitch is not turned off.
B. Remove electrical power from the engine ECM.
C. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
D. Perform a 45 N (10 lb) pull test on each of the wires that are associated with injector solenoids.
E. Check the harness and wiring for abrasions and for pinch points from the valve cover base to the injectors.
Wiring
Result: The connectors and the wiring are OK.
Proceed to Test Step 6.
Result: The connectors and/or wiring are NOT OK.
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 coupled. Perform an injector solenoid test in order to verify that the problem is resolved.
If the problem is not resolved, proceed to Test Step 6.
6. Check the Injector Harness under the Valve Cover for a Short Circuit
A. Turn the keyswitch to OFF. A strong electrical shock hazard is present if the keyswitch is not turned off.
B. Remove electrical power from the engine ECM.
C. Remove the valve cover in order to gain access to the suspect