812817A97 Mercury POWERHEAD ASSEMBLY

Illustration 1 g01255307
Typical circuit for the auxiliary brake output
Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01186024
Location of the J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect J1/P1 ECM connector. Also, thoroughly inspect the firewall bulkhead connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01255305
Terminal locations at the P1 ECM connector for the auxiliary brake
(P1-12) Output No. 3
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the auxiliary brake circuit.
Check the allen head screw for each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the circuit's wiring for abrasion and for pinch points. Expected Result:All connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring or replace the wiring, if necessary. Repair the connectors or replace the connectors, if necessary. Ensure that all of the seals are in the proper place. Ensure that all of the connectors are connected properly. Verify that the problem is resolved.STOPTest Step 2. Check the Parameter Settings
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Turn the keyswitch to the ON position.
Use Cat ET to verify that the following parameters are programmed correctly:
"Auxiliary Brake"
"Engine Retarder Minimum Vehicle Speed" (if applicable)
Turn the keyswitch to the OFF position. Expected Result:The parameters are programmed correctly.Results:
OK - The parameters are programmed correctly. Proceed to Test Step 3.
Not OK - At least one parameter is programmed incorrectly.Repair: Program the parameter to the correct value. Road test the vehicle. Continue with this procedure, if necessary.STOPTest Step 3. Check the Status Parameters
Access the status screen on Cat ET for the accelerator pedal position.
Turn the keyswitch to the ON position.
While the status screen is being monitored, depress the accelerator pedal several times and release the accelerator pedal several times.
Access the status screen on Cat ET for the clutch pedal position switch.
While the status screen is being monitored, depress the clutch pedal several times and release the clutch pedal several times.
Turn the keyswitch to the OFF position. Expected Result:The status parameters indicate that the circuits are operating correctly.Note: The clutch pedal position switch is ON when the clutch pedal is depressed. The clutch pedal position switch is OFF when the clutch pedal is released.Results:
OK - The status parameters indicate that the circuits are operating correctly. Proceed to Test Step 4.
Not OK - There is a problem with the accelerator pedal position.Repair: Refer to Troubleshooting, "Sensor Signal (PWM) - Test".STOP
Not OK - There is a problem with the clutch pedal position.Repair: Refer to Troubleshooting, "Speed Control (Auxiliary) - Test".STOPTest Step 4. Use Cat ET to Check the Relay and Solenoids
Turn the keyswitch to the ON position.
Click on the following menus in order to access the "Auxiliary Brake Special Test" on Cat ET:
"Diagnostics"
"Diagnostic Tests"
"Auxiliary Brake Special Test"
Set the dash switches to the "High Braking Level" for the auxiliary brake.
While you listen for the relay and solenoids to click, cycle the "Auxiliary Brake Special Test" from the ON to OFF and back to ON. Note: You may need to be near the engine in order to hear the click of the relay and solenoids.
Turn the keyswitch to the OFF position. Expected Result:There is an audible click from the relay and the solenoids.Results:
OK - There is an audible click from the relay and the solenoids. The ECM is operating correctly. The circuit is operating correctly.Repair: If the auxiliary brake is not operating correctly, there is a problem with a component in the circuit. Send the vehicle to the OEM dealer for repair.STOP
Not OK - There is no audible click from the relay or the solenoids. Proceed to Test Step 5.Test Step 5. Use Cat ET to Check the ECM
Disconnect the J1/P1 ECM con