PISTON & ROD GP 4848069 - Caterpillar

Batteries give off flammable fumes which can explode.To avoid injury or death, do not strike a match, cause a spark, or smoke in the vicinity of a battery.
Do not connect the bypass harness to the battery until the in-line fuse has been removed from the Battery+ line. If the fuse is not removed before connection to the battery, a spark may result.
Illustration 4 g03503564
Schematic of the bypass harness connector
Illustration 5 g03503677
Typical view of the pin locations on connector P1 for the bypass harness (1) Battery ground (GND) (2) Battery ground (GND) (3) Battery ground (GND) (7) Battery + (8) Battery + (9) Battery ground (GND) (10) Battery ground (GND) (15) Battery + (16) Battery + (20) J1939 (CAN) + (21) J1939 (CAN) - (23) Data link + (24) Data link - (40) Ignition keyswitch
Table 3
Troubleshooting Test Steps    Values    Results    
7. Connect an Electronic Service Tool and the ECM to another Battery
Note: Refer to Illustration 4 for details of the bypass harness.
A. Turn the keyswitch to the OFF position.
B. Connect the battery wires from the bypass harness of the electronic service tool to a different battery that is not on the engine.
   
The electronic service tool operates correctly    
Result: The electronic service tool operates correctly with the bypass harness - the fault is in the wiring.
Refer to Troubleshooting, "Ignition Keyswitch and Battery Supply Circuit - Test".
Result: The electronic service tool is not operating correctly.
Proceed to Test Step 8.
   
8. Check if a Replacement ECM Eliminates the Fault
A. Make sure that the latest flash file for the application is installed in the ECM. Refer to Troubleshooting, "Flash Programming".
B. Contact the Technical Communicator at a Cat Dealer.
Note: This consultation can greatly reduce the repair time.
C. If the Technical Communicator recommends the use of a test ECM, install a test ECM. Refer to Troubleshooting, "Replacing the ECM".
D. Turn the keyswitch to the ON position. Use the electronic service tool to verify that the repair eliminates the fault.
   
Fault eliminated    
Result: The fault is eliminated with the test ECM.
Reconnect the suspect ECM. If the fault returns with the suspect ECM, permanently install the replacement ECM.
Result: The fault is still present with the replacement ECM.
Do not use the replacement ECM.
Contact the Technical Communicator at a Cat Dealer.