PLATE 8N7954 - Caterpillar

System Operation Description:The Electronic Control Module (ECM) controls the throttle actuator by adjusting current flow through the actuator's solenoid.The 1440-05 diagnostic code is probably caused by a problem with an electrical connector or an open circuit in a harness. Under certain circumstances, the 1440-05 diagnostic code can occur if the low side wire is shorted to ground. The next likely cause is an open circuit inside the actuator solenoid. The least likely cause is a problem with the ECM.The 1440-06 diagnostic code is probably caused by a short circuit in a harness or a problem with an electrical connector. The next likely cause is a short circuit inside the actuator solenoid. The least likely cause is a problem with the ECM.
Illustration 1 g01075602
Schematic of the circuit for the throttle actuator
Test Step 1. Inspect the Electrical Connectors and WiringNote: This Test Step is important for troubleshooting a problem with instability.
Illustration 2 g01075604
Terminal box
(1) J2/P2 connectors for the ECM
(2) 16 amp circuit breaker
(3) J10/P10 connectors for the harness from the throttle actuator
Set the engine control to the OFF/RESET mode. Switch 16 amp circuit breaker (2) to the OFF position. Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Thoroughly inspect the following connectors:
J2/P2 connectors
J10/P10 connectors on the terminal box
Check the torque of the allen head screw for the ECM connector. The proper torque is 6 1 N m (55 9 lb in).
Illustration 3 g01075606
Harness side of the P2 connector
(P2-63) High side wire for the throttle actuator
(P2-64) Low side wire for the throttle actuator
Illustration 4 g00895202
Harness side of the P10 connector
(P10-C) High side wire for the throttle actuator
(P10-D) Low side wire for the throttle actuator
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the throttle actuator.
Illustration 5 g01075607
Throttle actuator
(4) Throttle actuator
(5) Connectors for the throttle actuator
Thoroughly inspect the connectors for the throttle actuator for moisture and for contamination. Check the harness and wiring for abrasion and for pinch points from the throttle actuator to the ECM. Expected Result:All of the connectors and terminals are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - The components are in good condition with proper connections. If you are troubleshooting a 1440-05 diagnostic code, proceed to Test Step 2. If you are troubleshooting a 1440-06 diagnostic code, proceed to Test Step 8.
Not OK - The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check the Solenoid and Harnesses for an Open Circuit
Set the engine control to the OFF/RESET mode. Switch the 16 amp circuit breaker OFF.
Disconnect the P2 connector.
Measure the resistance between terminals P2-63 and P2-64. During this measurement, wiggle the harnesses in order to check for an intermittent problem with the harness. Be sure to wiggle the harnesses near each of the connectors. Expected Result:The resistance is between 5.0 and 20.6 Ohms.Results:
OK - The resistance is between 5.0 and 20.6 Ohms. The