PLATE ASSEM. 6L6275 - Caterpillar

ground circuit connection.
A poor system voltage supply circuit connection.
A charging system component has failed.
The ECM has failed. This is unlikely. Note: Before performing this procedure, verify that all circuit breakers and fuses in the charging circuit and the ECM system supply circuit are closed. If a problem with a circuit breaker or a fuse 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 ECM
Turn the key start switch and the battery disconnect switch to the OFF position.
At the machine harness connector J1 for the ECM, insert a 7X-1710 Multimeter Probe along the system power supply contacts J1- 31,39,46 and 47 (wires 101-RD). Use the other multimeter probe to make contact to frame ground.
Turn the disconnect switch to the ON position.
Start the engine and run the engine at half throttle.
Measure the voltage between contacts J1-31,39,46 and 47 (wires 101-RD) and frame ground.
While observing the multimeter voltage measurement, wiggle the machine harness connectors for the ECM. Gently pull on the wires and gently move the wires around.
At the J1 harness connector for the ECM, insert the 7X-1710 Multimeter Probe that was used for the frame ground contact along the system power supply battery (-) contacts J1-13,23,56,57 and 70 (wires 202-BK).
Measure the voltage between contact J1-31 (wire 101-RD) and contacts J1-13,23,56,57 and 70 (wires 202-BK).
While observing the multimeter voltage measurement, wiggle the machine harness connectors for the ECM. Gently pull on the wires and move the wires around.Expected Result:Each voltage measurement is approximately the same and are in the range of 18 VDC to 32 VDC at all times during the manipulation of the harness and connectors.Results:
YES - Each voltage measurement is approximately the same and are in the range of 18 VDC to 32 VDC. The system voltage is correct at all times during the manipulation of the harness and connectors. Proceed to Test Step 6.
NO - The voltage measurements are approximately the same, however the voltage measurements are unstable. The voltage measurements are showing a large amount of variation. The manipulation of the machine harness and connectors does not affect the measurement. Proceed to Test Step 4.
NO - The measurement from the +battery contacts to frame ground are stable and are in the range of 18 VDC to 32 VDC, however, the measurement between the ECM +battery contact and the ECM (-) battery contacts are not stable or in the correct range at all times. Proceed to Test Step 2.Test Step 2. CHECK THE GROUND CIRCUITS
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector J1 from the ECM.
At the machine harness connector J1 for the ECM, measure the resistance between each of the five (5) battery (-) contacts and frame ground. The contacts for the battery (-) connections are illustrated in the connection diagram at the beginning of this procedure.Expected Result:Each resistance measurement is less than 5 ohms.Results:
YES - Each resistance measurement is less than