F10025 Force GASKET SET

Illustration 1 g01122143
Duty cycle versus throttle position
The signal that is produced by the TPS has a variable frequency. The frequency of the signal must be between 150 Hz and 1050 Hz or the ECM will activate an -08 diagnostic code. Use this procedure to troubleshoot these diagnostic codes:
91-08 Throttle Position signal abnormal
1249-08 Secondary Throttle Position signal abnormalA 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 Calibration required
268-02 Check Programmable Parameters
1249-13 Secondary Throttle Position 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 the synchronization switch, refer to diagnostic functional tests Troubleshooting, "Engine Synchronization Switch Circuit - Test".This troubleshooting procedure verifies that the signal from a TPS is valid at the ECM.When you make repairs to the circuit for the TPS, follow the guidelines in Special Instruction, REHS1187, "Electronic Installation Guide". This document provides information that will ensure that the TPS is protected from transient voltages and from problems that are caused by improper grounding.Two throttle position sensors are shown in Illustration 2. A vessel may contain more than one TPS. Each TPS may be connected to more than one ECM. Refer to the vessel's schematic diagram for the actual configuration. Use this procedure to troubleshoot all possible configurations.
Illustration 2 g01136782
Typical schematic for the throttle position sensor
Test Step 1. VERIFY THAT THE "SECONDARY THROTTLE ENABLE" PARAMETER IS PROGRAMMED CORRECTLY
Connect the Caterpillar Electronic Technician (ET) to the service tool connector.
Establish communication with the ECM that activated the 08 diagnostic code.
Verify that the "Secondary Throttle Enable" status is programmed correctly.
If the engine is equipped with a single TPS, verify that the "Secondary Throttle Enable" parameter is programmed to "Disabled".
If the engine is equipped with multiple throttle position sensors, verify that the "Secondary Throttle Enable" parameter is programmed to "Enabled". Expected Result:The "Secondary Throttle Enable" parameter is programmed correctly.Results:
OK - The "Secondary Throttle Enable" parameter is programmed correctly. Proceed to Test Step 2.
Not OK - The "Secondary Throttle Enable" parameter is not programmed correctly.Repair: Program the "Secondary Throttle Enable" parameter to the correct value.Verify that the repair eliminates the problem.STOPTest Step 2. INSPECT THE ELECTRICAL CONNECTORS AND THE WIRING
Remove the electrical power from the ECM.
Illustration 3 g01146374
Engine view (typical example)
(1) J1/P1 ECM connector
Illustration 4 g01146383
Engine view (typical example)
(2) P61 Customer connector
Thoroughly inspect connectors (1) and (2). Inspect the connections on each throttle position sensor. Refer to diagnostic functional tests Troubleshooting, "Electrical Connectors - Inspect".
Illustration 5 g01127049
P1 terminals that are associated with the throttle position sensor
(P1-66) Primary throttle position
(P1-68) Secondary throttle position
Illustration 6 g01188002
J61/P61 terminals that are associated with the throttle position sensor
(10) Primary throttle position
(4) Secondary throttle position
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the throttle position sensor.
Check the allen head screw on the customer connector and on each ECM connector for the proper torque. Refer to diagnostic functional tests Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasions and for pinch points from each throttle position sensor to the ECM and from the throttle position sensor to the electrical power source. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The wiring and the connectors appear to be OK. Proceed to Test Step 3.
Not OK - There is a problem with the wiring and/or the connectors.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly connected. Verify that the repair eliminates the problem.STOPTest Step 3. CHECK FOR SUPPLY VOLTAGE AT THE THROTTLE POSITION SENSOR
Disconnect the harness connector from the suspect throttle position sensor.
Restore the electrical power to the ECM.
Measure the voltage between terminals A and B on the harness connector for the throttle position sensor. Expected Result:The supply voltage is at least 11 VDC for a 12 volt system. The supply voltage is at least 22 VDC for a 24 volt system.Results:
OK - The supply voltage is at least 11 VDC for a 12 volt system. The supply voltage is at least 22 VDC for a 24 volt system. The supply voltage is reaching the sensor. Proceed to Test Step 4.
Not OK - The supply voltage is incorrect.Repair: The configuration of the wiring between the battery and the throttle position sensor depends on the vessel's configuration. The problem could be in the wiring or in a connector. There may be a problem with the battery.Perform the necessary repairs. When you make repairs to the wiring for the TPS, follow the guidelines in Special Instruction, REHS1187, "Electronic Installation Guide". Verify that the problem is resolved.STOPTest Step 4. CHECK THE SIGNA