SEAL-O-RING 4907797 - Caterpillar

Illustration 1 g01430920
Power terminals at the service tool connector
(Terminal A) +Battery
(Terminal B) −Battery
Table 2
Troubleshooting Test Steps Values Results
5. Check the Electrical Power to the Communication Adapter
A. Check for battery voltage at the service tool connector. Refer to Illustration 1.
Electrical Power
Result: OK - Battery voltage is present at the service tool connector.
Repair: Verify that the cable between the service tool connector and the communication adapter is OK. Replace the cable, if necessary.
Replace the communication adapter if the following conditions are true:
- There is power at the harness connector for the communication adapter.
- The communication adapter's "POWER" indicator is not illuminated.
Result: Battery voltage is not present at the service tool connector.
Repair: Inspect the application wiring and fuses. Determine the cause of the missing voltage. Make the necessary repairs.
Attempt to establish communication after the electrical power is at the service tool connector. Proceed to Test Step 6 if the service tool will not communicate on both data links.
Illustration 2 g01431084
Terminal locations at the J1/P1 ECM connectors for the ECM power supply circuit (typical wiring)
(48) Unswitched +Battery
(52) Unswitched +Battery
(53) Unswitched +Battery
(55) Unswitched +Battery
(57) Unswitched +Battery
(61) −Battery
(63) −Battery
(65) −Battery
(67) −Battery
(69) −Battery
(70) Keyswitch circuit
Illustration 3 g01817154
Schematic for the ECM power supply circuit (typical wiring diagram)
Table 3
Troubleshooting Test Steps Values Results
6. Check the Electrical Power to the ECM
A. Verify that electrical power for the application is turned on.
B. Refer to Illustration 2 and Illustration 3. Verify that battery voltage is present at the terminals that are indicated in the Illustration. Be sure to connect the voltmeter between the +Battery terminals and the −Battery terminals at the ECM connector.
C. Verify that battery voltage is present at P1-70 when the keyswitch circuit is powered.
Electrical Power
Result: OK - Battery voltage is present at all of the appropriate P1 terminals. The circuits for the battery power to the ECM are OK.
Proceed to Test Step 7.
Result: NOT OK - Battery voltage is not present at an ECM battery connection.
Repair: Inspect the application wiring, fuses, and/or circuit breakers. Determine the cause of the missing voltage. Make the necessary repairs.
Attempt to establish communication after the electrical problem at the ECM has been resolved. Continue with this procedure, if necessary.
7. Try to Establish Communication with a Bypass Harness
A. Connect the communication adapter to the engine ECM with a 217-0113 Wiring Harness (ECM BYPASS). This harness supports communication on both data links.
B. Attempt to establish communication.
Communication
Result: OK - Cat ET communicates on both data links when the bypass harness is used. There is a problem with the application wiring for one of the data links.
Repair: Repair the data link. Refer to Troubleshooting, "Data Link - Test"
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).