SWITCH AS-LIMIT 2677058 - Caterpillar

poor connection for supply voltage
A charging system component has failed
The ECM has failed, however ECM failure is unlikelyNote: Before performing this procedure, verify that all circuit breakers and fuses in the charging circuit and the supply circuit of the ECM system are closed. If a problem with a circuit breaker or a fuse is found, correct the problem. Verify that this diagnostic code is active before performing this procedure. Test Step 1. CHECK SYSTEM VOLTAGE AT THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At the J1 harness connector for the Implement ECM, insert a 7X-1710 Multimeter Probe along the contact J1-31 (wire 180-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 contact J1-31 (wire 180-RD) and frame ground.
While the resistance measurement is observed, wiggle the machine harness connectors of the ECM. Gently pull on the wires and move the wires.
At the J1 harness connector for the Implement ECM, insert the 7X-1710 Multimeter Probe along the contact J1-13 (wire A295-BK).
Measure the voltage between contact J1-31 (wire 180-RD) and contact J1-13 (wire A295-BK).
While the resistance measurement is observed, wiggle the machine harness connectors of the ECM. Gently pull on the wires and move the wires.Expected Result:Both voltages are approximately the same voltage. Both voltages are in the range of 18.0 VDC to 32.0 VDC at all times during the manipulation of the harness and the connectors.Results:
OK - Each voltage is approximately the same voltage. Each voltage is in the range of 18.0 VDC to 32.0 VDC. The system voltage is correct at all times during the manipulation of the harness and connectors. Proceed to Test Step 6.
NOT OK - Each voltage is approximately the same voltage, but the voltages are not stable. The voltages 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.
NOT OK - The voltage from the positive Battery contact to frame ground is in the range of 18.0 VDC to 32.0 VDC, but the measurement between the ECM positive Battery contact and the ECM2 negative Battery contact is not 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 J1 connector from the ECM.
At the J1 harness connector for the ECM, measure the resistance between each of the four negative battery contacts and the frame ground. The contacts for the negative battery connections are illustrated in the connection diagram at the beginning of this procedure.Expected Result:Each resistance measurement is less than 5.0 ohms.Results:
OK - Each resistance measurement is less than 5.0 ohms. The ground circuit is correct. Reconnect the J1 machine harness connector to the ECM before proceeding to the next test step. Proceed to Test Step 3.
NOT OK -