827509A10 Mercury CDM

Illustration 1 g01045566
Schematic diagram of the idle/rated switchThe engine is equipped with a remote control panel that includes a status control module and air/fuel ratio control. The idle/rated switch is shown in the "IDLE" position.
Illustration 2 g01045567
Schematic diagram of the idle/rated switchThe engine is configured for Canadian Standards Association (CSA). The engine is equipped with an optional remote control panel with air/fuel ratio control. The idle/rated switch is shown in the "IDLE" position.Test Step 1. Inspect the Electrical Connectors and the Wiring
Set the engine control to the OFF/RESET mode. Remove the electrical power from the engine.Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect each of the following connectors:
J1/P1 connectors on the ECM
Connections for the idle/rated switch
Illustration 3 g01045829
Harness side of the P1 connector (P1-3) Ground for the sensors (P1-36) Input for idle/rated switch
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the idle/rated switch.
Check the terminal strips for corrosion and for mechanical failure.
If the engine is equipped for CSA, check the harnesses and the wiring for abrasion and for pinch points between the idle/rated switch and the ECM.Expected Result:The connectors, pins, and sockets are connected properly. The terminal strips do not have corrosion or mechanical failure. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. Proceed to Test Step 2.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check the Wiring for an Open Circuit
Remove the electrical power from the engine.
Disconnect the P1/J1 connectors.
Use a multimeter to check for an open circuit between the points that are listed in Table 1. During each measurement, wiggle the wires in the harness in order to check for an intermittent problem. Be sure to wiggle the wires near each of the connectors.
Table 1
Resistance Measurements for the Wiring for the Idle/Rated Switch    
Connector and Terminal    Terminal on the Idle/Rated Switch    
P1-3 (Ground for the sensors)     The terminal that is connected to the C271-BK wire or the C270-BK wire    
P1-36 (Input for the idle/rated switch)     The terminal that is connected to the C273-WH wire    Expected Result:Each check of the resistance is less than 5 Ohms.Results:
OK - Each check of the resistance is less than 5 Ohms. Proceed to Test Step 3.
Not OK - At least one check of the resistance is greater than 5 Ohms.Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the problem is resolved.STOPTest Step 3. Check the Wiring for a Short Circuit
Disconnect the wiring from the idle/rated switch.
Measure the resistance between terminal J1-36 and all of the other terminals on the J1 connector.Expected Result:Each check of the resistance is greater than 5 Ohms.Results:
OK - Each check of the resistance is greater than 5 Ohms. The wiring does not have a short circuit. Proceed to Test Step 4.
Not OK - At least one check of the resistance is less than 5 Ohms. The wiring has a short circuit.Repair: Repair the connection and/or the wire, when possible. Replace parts, if necessary. Verify that the problem is resolved.STOPTest Step 4. Check the Idle/Rated Switch
Set the idle/rated switch to the "IDLE" position.
Measure the resistance between the terminals of the switch. Record the measurement.
Set the idle/rated switch to the "RATED" position.
Measure the resistance between the terminals of the switch. Record the measurement.Expected Result:When the switch was in the "IDLE" position, the measurement was an open circuit. When the switch was in the "RATED" position, the measurement was a short circuit. Results:
OK - The switch is operating correctly.Repair: Perform the following procedure:
Reconnect all of the connectors and the wiring.
Run the engine and check the operation of the switch.
If the engine does not respond to a change in the position of the switch, replace the ECM. Refer to Troubleshooting, "Replacing the ECM". Verify that the original problem is resolved.
If the engine responds to a change in the position of the switch, the problem is resolved.If you are troubleshooting an intermittent problem, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP