19614 1 Mercury TILT TUBE

Table 1
Diagnostic Codes Table    
Code and Description     Conditions which Generate this Code     System Response    
91-8 Throttle Position Sensor : Abnormal Frequency, Pulse Width, or Period     The Electronic Control Module (ECM) detects an incorrect frequency on the throttle signal or an incorrect duty cycle on the throttle signal. The frequency is below 150 Hz or the frequency in above 1000 Hz. The duty cycle is less than 5 percent or the duty cycle is greater than 95 percent.
This code is used when the parameter for the "Desired Speed Input Configuration" is configured to "PWM".     The code is logged. The ECM flags the throttle position as invalid data and a default value of zero percent is used. The engine speed is limited to low idle.    
1690-8 Throttle #2 Position Sensor : Abnormal Frequency, Pulse Width, or Period     The ECM detects an incorrect value for the throttle signal. The value for the analog input is outside the range of zero to five volts.
This code is used when the parameter for the "Desired Speed Input Configuration" is configured to "0 - 5 VDC".    The throttle position sensor provides the throttle signal to the engine's ECM. The output for rated speed is a pulse width modulated signal (PWM) at a constant frequency. The throttle position sensor 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 sensor's 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 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 in order to adjust for the new range.This application can also be equipped with a load sharing module. The load sharing module provides a throttle signal to the ECM. The output of the load sharing module allows multiple generators to share the load equally. The speed signal from the load sharing module varies with the position of the speed adjust potentiometer. The output signal is expressed as a percentage between 0 and 100 percent for the speed adjust.The speed controls are powered by keyswitch power. The return for the circuit is provided by the −Battery circuit.The ECM calculates the desired engine rpm from the throttle signal and the droop signal. 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.
Illustration 1 g01560364
Schematic for the speed control circuit (typical example)Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Thoroughly inspect the engine interface connector and the J1/P1 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details that are related to inspection of the electrical connectors.
Illustration 2 g01366736
Terminal locations at the P1 ECM connector that are for the speed control (P1-61) −Battery (P1-66) Throttle signal (P1-70) Keyswitch
Illustration 3 g01366739
Terminal locations at the engine interface connector that are for the speed control (Terminal 2) −Battery (Terminal 10) Throttle signal (Terminal 30) Keyswitch
Illustration 4 g01159881
Terminal locations at the connector for the throttle position sensor (Terminal A) −Battery (Terminal B) Keyswitch (Terminal C) Throttle signal
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the engine interface connector that are associated with the circuit.
Check the allen head screw on each ECM connector and the engine interface connector for the proper torque. refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the 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 connectors and wiring appear to be OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not OK.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Status for "Throttle Position"
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore electrical power to the ECM.
Observe the status for "Throttle Position" on Cat ET while you operate the throttle through the entire range of travel.
Remove electrical power from the ECM.Expected Result:The status is zero percent when the throttle is in the lowest position of travel. The status progressively increases to 100 percent when the throttle is in the highest position of travel.Results:
OK - The throttle position sensor is working properly.Repair: There may be an intermittent electrical problem with the harness or the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" if an intermittent electrical problem is suspected.STOP
Not OK - The throttle position that is displayed on Cat ET does not correspond to the movement of the throttle. Proceed to Test Step 3.Test Step 3. Check the Supply Voltage at the Sensor
Disconnect the throttle position sensor at the harness connector.
Restore electrical power to the ECM.
Measure the voltage across terminal A (+Battery) and terminal B (−Battery) on the harness side of the connector.
Remove electrical power from the ECM. Restore the wiring to the original configuration.Expected Result:The supply voltage measures 24 2 VDC at the sensor connector for 24 V systems. The supply voltage measures 12 2 VDC at the sensor connector for 12 V systems.Results:
OK - The correct voltage is measured at the sensor connector. The sensor is receiving the correct supply voltage. Proceed to Test Step 4.
Not OK - The voltage is not correct at the sensor connector.Repair: There is a problem in the keyswitch circuit that is between