955336 Volvo.Penta Hexagon screw

Illustration 1 g00712704
Schematic
Table 1
Correlation Between Throttle Switch Position and Status of the Throttle Inputs    
Throttle Switch Position    Status on ET    
"Throttle Input #1" "Throttle Input #2"    "Throttle Input #3"    "Throttle Input #4"    
Center     Off     On     Off     On    
Low Idle     On     On     Off     Off    
High Idle     Off     Off     On     On    Test Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect ECM connector J1/P1, machine connector J3/P3, and the throttle switch connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for corrosion, abrasion, and pinch points from the throttle switch to the ECM.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status on ET
Connect ET at the service tool connector.
Turn the keyswitch to the ON position.
Observe the status of the throttle switch and the throttle inputs on ET while you operate the throttle switch in each position.Expected Result:The status on ET should correspond with the information in Table 1.Results:
OK - The throttle switch is functioning properly at this time.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - Record the suspect input. Proceed to Test Step 3.Test Step 3. Jumper the Switch Input at the Throttle Switch Connector
Disconnect the throttle switch.
Observe the status of the suspect throttle input on ET.
Use a suitable piece of wire to short terminal 2 (Digital Return) to the terminal for the suspect throttle input at the throttle switch connector.
Observe the status of the suspect throttle input on ET.
Move the wire short from terminal 2 (Digital Return) to terminal 5 (Digital Return) of the throttle switch connector.
Observe the status of the suspect throttle input on ET.
Remove the wire short.Expected Result:The status of the suspect throttle input should be "Off" when the throttle switch connector is disconnected. The status should be "On" when the wire short is installed. The status should not change when the wire short is moved from terminal 2 to terminal 5.Results:
OK - The harness and the ECM are OK.Repair: Replace the throttle switch.Verify that the repair eliminates the problem.STOP
Not OK - Proceed to Test Step 4.Test Step 4. Check for Shorts in the Harness
Turn the keyswitch to the OFF/RESET position.
Disconnect ECM connector J1/P1 and the throttle switch connector.
Measure the resistance between engine ground and the terminal for the suspect throttle input at the throttle switch connector.
Measure the resistance between the terminal for the suspect throttle input and the remaining terminals at the throttle switch connector.Expected Result:Resistance should be greater than 20,000 for each reading.Results:
OK - Proceed to Test Step 5.
Not OK - There is a short in the harness between the ECM and the throttle switch.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Check Resistance through the Harness
Illustration 2 g00666871
ECM connector P1 (ECM side)
Use a suitable piece of wire to short terminal 5 (Digital Return) to the terminal of the suspect throttle input at the throttle switch connector.
Measure the resistance between P1:29 (Digital Return) and the terminal for the suspect throttle input at ECM connector P1.Expected Result:Resistance should be less than 10 Ohms.Results:
OK - Proceed to Test Step 6.
Not OK - There is an open circuit or excessive resistance in the harness.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 6. Check the Harness and the ECM
Illustration 3 g00666991
ECM connector P1 (wire side)
Turn the keyswitch to the OFF/RESET position.
Disconnect ECM connector J1/P1 and remove the wire for the suspect throttle input from ECM connector P1.
Reconnect all connectors.
Turn the keyswitch to the ON position.
Observe the status of the suspect throttle input on ET.
Turn the keyswitch to the OFF/RESET position.
Disconnect ECM connector J1/P1 an