3508C, 3512C, and 3516C Locomotive Engines Caterpillar

Probable Causes

• Batteries

• Battery cables

• Starting circuit

• Starting motor solenoid

• Starting motor

• Flywheel ring gear

• Prelubrication system (if applicable)

• Shutdown switch

• Faulty crank enable switch (if applicable)

• Transmission (if applicable)

• Engine accessories

• Hydraulic cylinder lock

• Internal engine problem

Recommended Actions

Batteries and/or Battery Cables

1. Inspect the main power switch, battery posts, and battery cables for loose connections and for corrosion. If the battery cables are corroded, remove the battery cables and clean the battery cables. Tighten any loose connections.

2. Inspect the batteries.

   1. Charge the batteries. Refer to Special Instruction, SEHS7633, "Battery Test Procedure".

   2. Load test the batteries. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6, 8 and 12 Volt Lead Acid Batteries".

Starting Motor Solenoid or Starting Circuit

1. Test the operation of the starting motor solenoid.

2. Check the wiring to the starting motor solenoid.

3. Check the operation of the circuit that is for the start interlock at the starter solenoid and at the ECM. Repair the circuit, if necessary. Refer to the Schematic for information that is related to the circuit for the start interlock.

Starting Motor or Flywheel Ring Gear

1. Test the operation of the starting motor.

2. Inspect the pinion for the starting motor and the flywheel ring gear for damage.

Prelubrication System (if applicable)

If equipped, inspect the prelubrication system for proper operation.

Shutdown Switch

Use Cat ET to monitor the status of the engine. Check the status of engine shutdowns that are "ACTIVE" due to shutdown switches. Determine the cause for the engine shutdown and take the necessary action in order to resolve the shutdown.

Crank Enable Switch (if applicable)

Ensure that the crank enable switch is not faulty.

Transmission (if applicable) or Engine Accessories

1. Ensure free movement of the driveline.

2. Remove any engine accessories that may lock up the engine and inspect any engine accessories that may lock up the engine.

   The following list illustrates examples of engine accessories that may lock up the engine:

   • Hydraulic pump that is driven from the rear gear group

   • Air compressor

   • Engine oil pump

   • Other components that are driven by the engine

Hydraulic Cylinder Lock

Check for fluid in the cylinders (hydraulic cylinder lock) by removing the individual unit injectors.

Note: Drain the fuel from the cylinder head. Fuel will flow from the cylinder head into the cylinders when the unit injector is removed.

Internal Engine Problem

Disassemble the engine. Refer to the Disassembly and Assembly manual. Inspect the internal components for the following conditions:

• Seizure

• Broken components

• Bent components