23021654 Volvo.Penta Cotter

Table 1
J1939 Code and Description CDL Code and Description Comments
91-8
Accelerator Pedal Position #1 : Abnormal Frequency, Pulse Width, or Period 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 code is logged. The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle. The direct fuel control mode enables the engine to be controlled by an external governor. Install the components of the signal converter for the direct fuel control to operate in direct fuel control mode. The "Direct Fuel Control Mode" parameter must be programmed to "Enabled" in order for the Electronic Control Module (ECM) to respond properly to the external governor.The input to the signal converter is a 0 to 200 mA signal. The signal is received from the external governor. The output signal from the signal converter is a Pulse Width Modulated signal (PWM).The output signal varies with the current to the signal converter. The ECM calculates the desired fuel from the PWM signal.The duty cycle for a valid signal is between 5 and 95 percent. If an invalid signal is received, the engine will automatically be set to a minimum fuel setting and the engine will shutdown.The following functions are not used in direct fuel control mode.
Low idle
Crank terminate speed
Cooldown speed
Illustration 1 g06193456
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information.
C. Perform a 45 N (10 lb) pull test on the connector wires.
D. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled.
If the problem is not resolved, proceed to Test Step 2.
2. Check the Current Input to the Signal Converter
A. Turn the main disconnect switch to the ON position.
B. Measure the current to the signal converter.
Note: Some external governors may only be able to output approximately 150 mA. Do not recognize this output as a problem with the external governor.
0 mA to 200 mA
Result: The current is within the correct range.
Proceed to Test Step 3.
Result: The current is not within the correct range.
Repair: Replace the external governor that is supplying the controlling current.
Verify that the repair eliminated the problem.
3. Inspect the Batteries
A. Measure no-load battery voltage at the battery terminals. Refer to Testing and Adjusting, Test Tools for the Electrical System for additional information.
B. Charge the batteries, if necessary. Refer to the Special Instruction, SEHS7633, Battery Test Procedure for additional information.
C. Load-test the batteries. Refer to the Operating Manual, SEHS9249, Use of 4C-4911 Battery Load Tester for 6, 8 V and 12 V Lead Acid Batteries for additional information.
Batteries
Result: The voltage measures 24 3 VDC.
Proceed to Test Step 4.
Result: The voltage is not 24 3 VDC.
Repair: The batteries or the alternator are causing the problem. Recharge the batteries or replace the batteries. Refer to Testing and Adjusting, Electrical System for additional information.
Verify that the repair eliminated the problem.
4. Check the Voltage at the Signal Converter
A. Turn the main disconnect switch to the ON position.
B. Connect one probe of the voltmeter to the +Battery terminal at the signal converter.
C. Connect one probe of the voltmeter to the terminal for the sensor return at the signal converter.
24 3 VDC
Result: The voltage is 24 3 VDC.
Proceed to Test Step 5.
Result: The voltage is not 24 3 VDC.
Repair: Check the wiring and/or the connectors that are between the battery and the signal converter. Repair or replace the wiring and/or connectors.
Verify that the repair eliminated the problem.
5. Check the Throttle Position
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Turn the Engine Control Switch (ECS) to the STOP position.
C. Use Cat ET to monitor following:
- Throttle position
D. Vary the current to the signal converter.
Throttle varies from 0 to 100 Percent
Result: The throttle position on Cat ET corresponds with the current input.
Repair: Check for codes.
Result: The throttle position on Cat ET does not correspond to the current input.
Proceed to Test Step 6.
6. Check the Signal from the Signal Converter
A. Turn the main disconnect switch to the OFF position.
B. Remove the signal wire from the signal converter.
C. Turn the main disconnect switch to the ON position.
D. Set the multimeter to "VDC".
E. Press the "Hz" button twice so that the "%" symbol is displayed.
F. Place one probe on the signal wire of the signal converter.
G. Place the other probe on the −Battery terminal of the signal converter.
H. Monitor the output of the percent duty cycle from the signal converter.
J. Adjust the current input from a low current setting to a high current setting.
Note: The throttle position on Cat ET will not match the percent duty cycle on the multimeter.
Signal Converter
Result: The correct signal is being supplied.
Proceed to Test Step 7.
Result: The duty cycle is not correct on the multimeter.
Repair: Temporarily install another signal converter. Verify that the problem is no longer present. Reinstall the old signal converter. If the problem returns, replace the signal converter.
Verify that the repair eliminated the problem.
7. Check the Signal at the Electronic Control Module (ECM)
A. Turn the main disconnect switch to the OFF position.
B. Replace the signal wire on the signal converter.
C. Remove the signal wire from terminal P1-66 at the ECM connector.
D. Reconnect ECM connector J1/P1
E. Turn the main disconnect switch to the ON position.
F. Set the multimeter to "VDC".
G. Press the "Hz" button twice so that the "%" symbol is displayed.
H. Monitor the output of the percent duty cycle from the signal converter. Connect the meter between the following:
- P1-66 (ECM) and a known good ground.
J. Vary the input current to the signal converter.
Duty