BEARING-SLEEVE 6T4176 - Caterpillar

System Operation Description:Use this procedure to troubleshoot the electrical system if a problem is suspected with the circuit for the Engine Control Switch (ECS) or if the diagnostic code in Table 1 is active or easily repeated.
Table 1
Diagnostic Codes Table
Code Conditions which Generate this Code System Response
336-2 Engine Control Switch : Erratic, Intermittent, or Incorrect The inputs from the ECS are in a different state. The code is logged. The Electronic Control Module (ECM) receives two input signals from the ECS. The two input signals should have the same logic level. If two different levels of logic are detected during the powerup, the ECM will determine that one of the signals is incorrect. The duplication of the signals permits the ECM to know if there is a problem in the wiring.When both of the input signals are high or open, the ECM assumes that the ECS is in the STOP position. When both of the input signals are low or shorted to the −Battery, the ECM assumes that the ECS is in the START position. After the ECS is turned to the START position, the ECM will initiate the starting sequence. The ECM will energize the prelube system if the prelube system is available and activated. After the prelube cycle is completed, the ECM will energize the starting solenoids for the starting motors. If both of the signals go high or open while the engine is running, the injection signals to the injector solenoids will be stopped and the engine will shut down.If the engine is running and one of the inputs from the ECS changes states, the ECM will ignore the inputs from the ECS until power is cycled to the ECM. If this occurs, you must use the emergency stop switch or you must disconnect the power to the ECM in order to shut down the engine.If the inputs from the ECS are in opposite states at the beginning of a crank cycle, the ECM will not initiate the crank cycle. If this condition occurs, the engine may be started by using the manual crank switch. If you start the engine with the manual crank switch, you must use the emergency stop switch or you must disconnect the power to the ECM in order to shut down the engine. A diagnostic code will be logged and a diagnostic code will be active for this problem. The diagnostic code for this problem will be active until the ECM is powered down.
Illustration 1 g01382553
Typical schematic
Illustration 2 g01382297
P1 ECM connector
(P1-21) Start/Run/Stop switch 1
(P1-22) Start/Run/Stop switch 2
Illustration 3 g01382298
Customer connector
(Terminal 46) Start/Run/Stop switch 1
(Terminal 47) Start/Run/Stop switch 2
Illustration 4 g01234146
Location of ECM connectors
Test Step 1. Inspect Electrical Connectors and Wiring
Turn the main disconnect switch to the OFF position.
Thoroughly inspect the ECM connectors. Inspect all of the other connectors for the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM