882432 Mercruiser STUD

Illustration 1 g00709269
SchematicTest 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 decelerator position sensor connector J90/P90. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.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. Inspect the Decelerator Pedal Assembly
Inspect the decelerator pedal assembly for components that are loose, bent, missing, or worn.
Slowly depress the pedal and release the pedal.Expected Result:The decelerator pedal assembly should operate smoothly without excessive drag. The pedal should return to the low idle position without assistance in less than one second.Results:
OK - The decelerator pedal assembly functions properly. Proceed to Test Step 3.
Not OK - Repair: Repair the decelerator pedal assembly, as required.STOPTest Step 3. Check the Status on ET
Connect ET to the service tool connector.
Turn the keyswitch to the ON position.
Observe the status for "Decelerator Position" on ET while you operate the decelerator pedal.Expected Result:The status should be approximately 0 percent when the decelerator pedal is released. The status should progressively increase to 100 percent when the decelerator pedal is fully depressed.Note: This range can change depending on the adjustment of the decelerator pedal assembly.Results:
OK - The decelerator position sensor is working properly.Repair: Refer to Troubleshooting, "Electrical Connectors - Inspect" if the problem is intermittent.STOP
Not OK - Proceed to Test Step 4.Test Step 4. Check the Supply Voltage at the Sensor
Install a 7X-6370 Adapter Cable (3 Pin DT Breakout) at decelerator position sensor connector J90/P90.
Turn the keyswitch to the ON position.
Measure the voltage across terminal A (Digital Sensor +8 VDC) and terminal B (Digital Return) at the J90/P90 breakout.Expected Result:The supply voltage should be 8.0 0.5 VDC.Results:
OK - The sensor is receiving the correct supply voltage. Proceed to Test Step 5.
Not OK - Proceed to Test Step 10.Test Step 5. Check the Isolated Signal Frequency and the Duty Cycle at the Sensor
Remove the wire from the harness side of P90:C (Signal).
Turn the keyswitch to the ON position.
Measure the frequency and the duty cycle between terminal B (Digital Return) and terminal C (Signal) at the J90/P90 breakout while you operate the decelerator pedal.
Turn the keyswitch to the OFF/RESET position.
Reinstall the wire in P90:C (Signal).Expected Result:The frequency should be between 150 and 1000 Hz. The duty cycle should be approximately 57 percent when the pedal is released. The duty cycle should be approximately 32 percent when the pedal is fully depressed.Results:
OK - The sensor is producing a valid signal. Proceed to Test Step 6.
Not OK - The sensor is not producing a valid signal.Repair: Replace the decelerator position sensor.Verify that the repair eliminates the problem.STOPTest Step 6. Check for a Short Circuit in the Wiring Harness
Disconnect ECM connector J1/P1, ECM connector J2/P2, and decelerator position sensor connector J90/P90.
Measure the following resistances:
P90:A (Digital Sensor +8 VDC) and P90:B (Digital Return)
P90:A (Digital Sensor +8 VDC) and P90:C (Decelerator Position)
P90:B (Digital Return) and P90:C (Decelerator Position)Expected Result:The resistance should be greater than 20,000 Ohms for each measurement.Results:
OK - There are no shorts in the harness. Proceed to Test Step 7.
Not OK - There is a short circuit in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 7. Check the Resistance through the Harness
Illustration 2 g00676466
ECM connector P1
Illustration 3 g00709606
ECM connector P2
Fabricate a jumper wire with pins at both ends.
Use the jumper wire to short P90:A (Digital Sensor +8 VDC) and P90:C (Decelerator Position) together.
Measure the resistance between P2:24 (Decelerator Position) and P1:35 (Digital Sensor +8 VDC).
Move the one end of the jumper wire from P90:A (Digital Sensor +8 VDC) to P90:B (Digital Return). Leave the other end in P90:C (Decelerator Position) together.
Measure the resistance between P2:24 (Decelerator Position) and P1:29 (Digital Return).
Remove the jumper wire and reconnect all of the connectors.Expected Result:The resistance should be less than 10 Ohms for each measurement.Results:
OK - The harness is good. Proceed to Test Step 8.
Not OK - There is an open circuit or excessive resistance in the harness or the connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 8. Check the Signal Frequency and the Duty Cycle at the ECM
Illustration 4 g00676466
J1/P1 breakout
Illustration 5 g00709606
J2/P2 breakout
Install a 7X-1715 Adapter Cable (40 Pin Breakout) at ECM connector J1/P1.
Install a 7X-1715 Adapter Cable (40 Pin Breakout) at ECM connector J2/P2.
Turn the keyswitch to the ON position.
Measure the frequency and the duty cycle between P2:24 (Decelerator Position) and P1:29 (Digital Return) at the breakouts while you operate the decelerator.
Turn the keyswitch to the OFF/RESET position.Expected Result:The frequency should be between 150 and 1000 Hz. The duty cycle should be approximately 57 percent when the pedal is released. The duty cycle should be approximately 32 percent when the pedal is fully depressed.Results:
OK - A valid sensor signal is reaching the ECM. Proceed to Test Step 9.
Not OK - There is an