YOKE ASSEM. 7P7730 - Caterpillar

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 the connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect", if an intermittent electrical problem is suspected.
STOP
Result: The throttle position that is displayed on Cat ET does not correspond to the movement of the throttle.
Proceed to Test Step 4.
4. Check the Supply Voltage at the Sensor
A. Disconnect the suspect throttle position sensor at the harness connector.
B. Restore electrical power to the ECM. Turn the keyswitch to the ON position.
C. Measure the voltage across terminal A (+Battery) and terminal B (−Battery) on the harness side of the connector.
D. Remove electrical power from the ECM. Turn the keyswitch to the OFF position.
E. Restore the wiring to the original configuration.
The supply voltage measures 24 2 VDC at the sensor connector.
Result: The correct supply voltage is measured at the sensor connector. The sensor is receiving the correct supply voltage.
Proceed to Test Step 5.
Result: The voltage is not correct at the sensor connector.
There is a problem in