853239 Mercruiser WASHER

Illustration 1 g00784488
Typical schematic
Test Step 1. Check for Connector Damage.
Turn the breaker at the battery to the OFF position.
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
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 should not have corrosion, abrasion or pinch points.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check for a Short Circuit in the Wiring Harness.Note: The circuit for the front engine begins with the letter T. The circuit for the rear engine begins with the letter R. The circuit for the master ECM begins with the letter X.
Disconnect ECM connector J1/P1 and all of the digital sensors if you are troubleshooting the digital supply for an exhaust temperature sensor. Disconnect the Master ECM connector J1/P1 and J2/P2 if you are troubleshooting the digital supply for the throttle position sensor.
Measure the resistance between the digital supply P1-35 (800-OR(Orange)) and the digital return P1-29 (998-BR(Brown)) on connector P1 if you are troubleshooting the digital supply for an exhaust temperature sensor. Measure the resistance between the digital supply P2-35 (X800-OR(Orange)) and the digital return P1-29 (X998-BR(Brown)) if you are troubleshooting the digital supply for the throttle position sensor.
Measure the resistance between the digital supply P1-35 (800-OR(Orange)) and the engine ground if you are troubleshooting the digital supply for an exhaust temperature sensor. Measure the resistance between the digital supply P2-35 (X800-OR(Orange)) and the engine ground if you are troubleshooting the digital supply for the throttle position sensor.
Measure the resistance between the digital return P1-29 (998-BR(Brown)) and the engine ground. Expected Result:The resistance should be greater than 20,000 Ohms for each measurement.Results:
OK - The resistance is greater than 20,000 Ohms. Proceed to Test Step 3.
Not OK - The resistance is less than 20,000 Ohms.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 3. Check the Digital Supply Voltage at the ECM.Note: The circuit for the front engine begins with the letter T. The circuit for the rear engine begins with the letter R. The circuit for the master ECM begins with the letter X.
Remove the wire P1-35 (800-OR(Orange)) from the harness side of ECM connector P1 if you are troubleshooting the digital supply for an exhaust temperature sensor. Install a wire jumper with a socket on one end into P1-35. Remove the wire P2-35 (X800-OR(Orange)) from the harness side of ECM connector P2 if you are troubleshooting the digital supply for the throttle position sensor. Install a wire jumper with a socket on one end into P2-35.
Remove the wire P1-29 (998-BR(Brown)) from the harness side of ECM connector P1. Install a wire jumper with a socket on one end into P1-29. Note: If you remove the sensor common from the ECM, an open circuit diagnostic code will be generated for all sensors that use the sensor common. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Reconnect ECM connector J1/P1 if you are troubleshooting the digital supply for an exhaust temperature sensor. Reconnect the Master ECM connector J1/P1 and J2/P2 if you are troubleshooting the digital supply for the throttle position sensor.
Turn the breaker at the battery to the ON position.
Turn the keyswitch to the ON position. The engine should be off.
Measure the voltage between the jumper in P1-35 and the jumper in P1-29 if you are troubleshooting the digital supply for an exhaust temperature sensor. Measure the voltage between the jumper in P2-35 and the jumper in P1-29 if you are troubleshooting the digital supply for the throttle position sensor.
Turn the keyswitch to the OFF position.
Remove the wire jumpers and reconnect all wires. Reconnect ECM connector J1/P1 and ECM connector J2/P2, if necessary. Expected Result:The supply voltage should be 8.0 0.4 VDC.Results:
OK - The supply voltage is 8.0 0.4 VDC. The digital sensor supply is producing the correct voltage. Proceed to Test Step 4.
Not OK - The supply voltage is not 8.0 0.4 VDC. The digital sensor is not producing the correct voltage.Repair: Perform the diagnostic functional test Troubleshooting, "Electrical Power Supply".STOPTest Step 4. Check the Digital Sensor Supply Voltage at the Sensor Connector.Note: The circuit for the front engine begins with the letter T. The circuit for the rear engine begins with the letter R. The circuit for the master ECM begins with the letter X.
Turn the keyswitch to the ON position. The engine should be off.
Measure the digital sensor supply voltage between the digital supply terminal-A (800-OR(Orange)) and the digital return terminal-B (998-BR(Brown)) of all the digital sensors. Note: If the sensor is disconnected from the harness, an open circuit diagnostic code will be generated for that sensor. Troubleshoot the original code. Delete the logged diagnostic codes when you are finished.
Turn the keyswitch to the OFF position. Expected Result:The supply vo