1360_101 Volvo.Penta Rocker arm shaft

Note: If the vessel is equipped with a Multi-Station Control System (MSCS), refer to Service Manual, RENR7651, "Marine Multi-Station Control System" for additional information that is related to troubleshooting the speed control circuits.Note: When you make repairs to the circuit for the Throttle Position Sensor (TPS), follow the guidelines that are found in Special Instruction, REHS1187, "Electronic Installation Guide". This document provides information that ensures that the TPS is protected from transient voltages and from problems that are caused by improper grounding.Note: If one of the above diagnostic codes is active, troubleshoot that code before you continue with this procedure. If you suspect a problem with engine synchronization, refer to Troubleshooting, "Synchronization - Test".A problem with the circuit for the synchronization switch may prevent the ECM from responding to a valid signal from the TPS. The following active diagnostic codes will also prevent the ECM from responding to the throttle input:
91-13 Throttle Position Sensor calibration required
1249-13 Secondary Throttle Position Sensor calibration requiredIf one of the above diagnostic codes is active, troubleshoot that code before you continue with this procedure. If you suspect a problem with engine synchronization, refer to Troubleshooting, "Synchronization - Test".The TPS provides the throttle signal to the engines ECM. The output for rated speed is a Pulse Width Modulated Signal (PWM) at a constant frequency. The TPS produces a minimum duty cycle in the lowest position and a maximum duty cycle in the highest position of the sensor. When the sensor is in the lowest position, the ECM translates the sensors output signal to a throttle position of 0 percent. When the sensor is placed in the highest position, the ECM translates the output signal to a throttle position of 100 percent.The throttle position sensor is powered by keyswitch power. The return for the circuit is provided by the −Battery circuit.The ECM uses an automatic calibration function that allows the ECM to maximize the usable range of the sensor. The automatic calibration function assumes a range of PWM duty cycle at powerup. If the duty cycle of the sensor exceeds this initial range, the automatic calibration function adjusts the limits of the duty cycle to adjust for the new range.The throttle signal is valid when the duty cycle is in the range of 5 to 95 percent. If the ECM determines that the throttle signal is invalid, the engine rpm will be set to the programmed low idle.The TPS provides the throttle signal to the engines ECM. The output for rated speed is a Pulse Width Modulated Signal (PWM) at a constant frequency. The TPS produces a minimum duty cycle in the lowest position and a maximum duty cycle in the highest position of the sensor. When the sensor is in the lowest position, the ECM translates the sensors output signal to a throttle position of 0 percent. When the sensor is placed in the highest position, the ECM translates the output signal to a throttle position of 100 percent.The throttle position sensor is powered by keyswitch power. The return for the circuit is provided by the −Battery circuit.The ECM uses an automatic calibration function that allows the ECM to maximize the usable range of the sensor. The automatic calibration function assumes a range of PWM duty cycle at powerup. If the duty cycle of the sensor exceeds this initial range, the automatic calibration function adjusts the limits of the duty cycle to adjust for the new range.The throttle signal is valid when the duty cycle is in the range of 5 to 95 percent. If the ECM determines that the throttle signal is invalid, the engine rpm will be set to the programmed low idle.Two throttle position sensors are shown in Illustration 1. A vessel may contain more than one TPS. Each TPS may be connected to more than one ECM. Refer to the vessels schematic diagram for the actual configuration. Use this procedure to troubleshoot all possible configurations.
Illustration 1 g01377320
Table 2
Troubleshooting Test Steps Values Results
1. Verify that the "Secondary Throttle Enable Status" Parameter is Programmed Correctly
A. Remove electrical power from the ECM.
B. Connect the Cat Electronic Technician (ET) to the service tool connector.
C. Restore electrical power to the ECM.
D. Establish communication with the ECM.
E. Verify that the "Secondary Throttle Enable Status" parameter is programmed correctly.
1. If the engine is equipped with a single TPS, verify that the "Secondary Throttle Enable Status" parameter is programmed to "Disabled".
2. If the engine is equipped with multiple throttle position sensors, verify that the "Secondary Throttle Enable" parameter is programmed to "Enabled".
Parameter
Result: The "Secondary Throttle Enable" parameter is programmed correctly.
Proceed to Test Step 2.
Result: The "Secondary Throttle Enable" parameter is not programmed correctly.
Program the "Secondary Throttle Enable" parameter to the correct value. Verify that the repair eliminates the problem.
STOP
2. Inspect the Electrical Connectors and the Wiring
A. Thoroughly inspect connectors. Also, thoroughly inspect all of the other connectors that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect", for details that are related to inspection of the electrical connectors.
B. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the customer connector that are associated with the circuit.
C. Check the allen head screw on each ECM connector and the customer connector for the proper torque. refer to Troubleshooting, "Electrical Connectors - Inspect", for the correct torque values.
D. Check the harness and the wiring for abrasion and for pinch points.
Connectors, Pins, and Sockets
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 3.
Result: The connectors and/or wiring are not OK.
Repair the connectors or wiring and/or replace the connectors or wiring.
STOP
3. Check the Status for "Throttle Position"
A. Connect Cat ET to the service tool connector.
B. Restore electrical power to the ECM.
C. Observe the status for "Throttle Position" on Cat ET while you operate the throttle that is for the suspect sensor through the entire range of travel.
D. Remove electrical power from the ECM.
Throttle
Result: The throttle position sensor is working properly.
There may be an intermittent electrical problem with the harness or