CONTROL GP-ENGINE ELECTRONIC 3223617 - Caterpillar

Test Step 1. CHECK SYSTEM VOLTAGE THE ECM
Turn the disconnect switch and the key start switch to the OFF position.
At the J1 harness connector for the Machine ECM, insert a 7X-1710 Multimeter Probe along the system power supply contact J1-31 (wire 140-RD(Red)). 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 140-RD(Red)) and frame ground.
While observing the multimeter resistance measurement, wiggle the machine harness connectors for the ECM. Gently pull on the wires and move the wires around.
At the J1 harness connector for the Implement ECM, insert the 7X-1710 Multimeter Probe that was used for the frame ground contact along the system power supply negative battery contact J1-13 (wire 202-BK(Black)).
Measure the voltage between contact J1-31 (wire 140-RD(Red)) and contact J1-13 (wire 202-BK(Black)).
While observing the multimeter resistance measurement, wiggle the machine harness connectors for the ECM. Gently pull on the wires and move the wires around. Expected Result:Both voltage measurements are approximately the same and are in the range of 18.0 VDC to 32.0 VDC at all times during the manipulation of the harness and connectors.Results:
OK - Each voltage measurement is approximately the same and 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 measurement is approximately the same, however, the measurements are not stable. 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.
NOT OK - The measurement from the positive battery contact to frame ground is stable and is in the range of 18.0 VDC to 32.0 VDC, however, the measurement between the ECM positive battery contact and the ECM negative battery contact is not stable 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 frame ground. The contacts for the four 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 - One or more of the resistance measurements is greater than 5.0 ohms. There is an open circuit or a poor connection in the ground circuit.Repair: The open or possible poor connection is in the ECM ground circuit (wire 202-BK(Black)) in the machine harness. Refer to the