PISTON 2384694 - Caterpillar

Illustration 1 g02319057
Transmission/Chassis ECM system voltage connections
This diagnostic code is associated with the supply voltage of the Transmission/Chassis ECM. The ECM activates this diagnostic code when the system voltage is above 32.0 VDC.The possible causes of this diagnostic code are listed below:
Charging system component failure
Harness failure
The ECM failure, however ECM failure is unlikelyNote: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can be the cause of an electrical circuit problem. Verify that all connections in the circuit are clean, secure, and in good condition. If a connection problem is found, correct the problem and verify that this diagnostic code is active before performing this procedure. Test Step 1. CHECK SYSTEM VOLTAGE AT THE TRANSMISSION/CHASSIS ECM
Turn off the disconnect switch and the keyswitch.
At the J1 harness connector for the transmission/chassis ECM, insert a 7X-1710 Multimeter Probe along the positive battery contact, J1-31 (wire 126-RD(Red)). Use the other multimeter probe to contact the frame ground.
Turn on the disconnect switch.
Start the engine and run at half throttle.
Measure the voltage between contact J1-31, (wire 126-RD(Red)) and the frame ground.
At the J1 harness connector for the ECM, insert the 7X-1710 Multimeter Probe along the negative battery contact J1-13 (wire A202-BK(Black)).
Measure the voltage between contact J1-31 (wire 126-RD(Red)) and contact J1-13 (wire A202-BK(Black)). Expected Result:Both voltages are approximately the same and are 18 to 32 VDC.Results:
OK - Voltages are approximately the same and are 18 to 32 VDC. Proceed to Test Step 5.
NOT OK - Voltages are approximately the same, but are greater than 32 VDC. Proceed to Test Step 3.
NOT OK - The voltage from the positive battery contact to frame (ground) is 18 to 32 VDC. However, the voltage between the ECM positive battery contact and the ECM negative battery contact is not 18 to 32 VDC. The ground circuit may have failed. Proceed to Test Step 2.Test Step 2. CHECK THE GROUND CIRCUITS
Turn the keyswitch and the disconnect switch off.
Disconnect the harness J1 connector from the ECM.
At the J1 harness connector for the ECM, measure the resistance between each negative battery contact and ground. The contacts for the negative battery connections are shown in Illustration 1. Expected Result:Each resistance is less than 5.0 ohms.Results:
OK - Each resistance is less than 5.0 ohms. Reconnect the J1 harness connector to the ECM before proceeding to the next test step. Proceed to Test Step 3.
NOT OK - A resistance is greater than 5.0 ohms. There is an open or possible poor connection in ground wire A202-BK(Black) of the ECM circuit. Repair: Check the ground A202-BK(Black) connection at the rear frame. Ensure that the ground connection is clean, tight, and in good condition. Check all of the ground circuit connectors and splice points. Ensure that all connections are clean, tight, and in good condition. Repair or replace the harness.STOPTest Step 3. CHECK THE ALTERNATOR CURRENT OUTPUT
Before performing this test step, partially discharge the batteries. Crank the engine for approximately 30 seconds without starting the engine or turn