RENR5042-02 175 Troubleshooting Section Expected Result: C. Connect a multimeter between terminals 66 and 5 on the breakout t. Each resistance measurement indicates an open circuit. D. Turn the keyswitch to the ON position. Results: E. Measure the frequency of the throttle position signal. Slowly move the throttle from low idle to high idle and back to low idle while you measure the frequency of the signal. OK – Each resistance measurement indicates an open circuit. Proceed to Test Step 5. Not OK At least one resistance measurement does not indicate an open circuit. There is a problem with the signal wire for the throttle position sensor. F. Observe the “Active Diagnostic” screen on Cat ET.
Slowly move the throttle from the low idle position to the high idle position. Look for a 091-08 diagnostic code while you move the throttle. Repair: The problem could be in the wiring or in a connector. Repair the wiring and/or the connector, when possible. Replace parts, if necessary. Verify that the problem is resolved. Expected Result: The frequency of the signal remains between 150 Hz and 1050 Hz as you move the throttle. A 091-08 diagnostic code is not activated. STOP. Test Step 4. Check the Signal Wire for an Open Circuit Results: OK – The frequency of the signal remains between 150 Hz and 1050 Hz as you move the throttle. A 091-08 diagnostic code is not activated. Note:
Be sure to wiggle the harnesses during the following measurement. Be sure to wiggle each harness near each connector. Repair: Perform the following procedure: Measure the resistance between terminal P1-66 and terminal P403-C. 1. Turn the keyswitch to the off position. 2. Remove the 208-0059 Adapter Cable As (70-PIN BREAKOUT). Expected Result: The resistance measurement is less than ten Ohms. 3. Connect the J1/P1 connectors. Results: 4. Turn the keyswitch to the ON position. OK The resistance measurement is less than ten Ohms. Connect the P403 connector. Proceed to Test Step 5. 5. Operate the throttle throughout the entire range. If the problem does not recur, the problem is resolved.
The original problem was probably caused by a poor electrical connection. Return the engine to service. Not OK – The resistance measurement is greater than ten Ohms. There is a problem with the signal wire. Repair: The problem could be in the wiring or in a connector. Repair the wiring and/or the connector, when possible. Replace parts, if necessary. Verify that the problem is resolved. STOP. Not OK – The frequency of the signal is incorrect. A 091-08 diagnostic code is activated. Repair: Perform the following procedure: STOP. Test Step 5. Check the Frequency of the Throttle Position Signal at the ECM 1. Turn the keyswitch to the off position. 2. Replace the throttle position sensor.
Check for a 091-08 diagnostic code again. A. Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, “Electronic Service Tools”. If the diagnostic code does not recur, the problem is resolved. Return the engine to service. B. Connect a 208-0059 Adapter Cable As (70-PIN BREAKOUT) between the P1 connector and the J1 connector.