3406E and 3456 Industrial Engines Systems Operation – General Information

Illustration 1 g00425099
Left side view

(1) Fuel priming pump. (2) Fuel transfer pump. (3) Primary fuel filter. (4) Fuel distribution block. (5) Fuel filter. (6) Electronic Control Module (ECM).

Illustration 2 g00425103
Right side view

(8) Exhaust manifold. (9) Turbocharger. (10) Temperature regulator housing. (11) Water pump. (12) Oil cooler. (13) Oil filter.

Illustration 3 g00425105
Top view

(1) Fuel priming pump. (8) Exhaust manifold. (9) Turbocharger. (14) Flywheel housing.

Illustration 4 g00425106
Front view

(15) Front timing gear housing. (16) Oil pressure fill gage. (17) Vibration damper.

Illustration 5 g00425107
Rear view

(14) Flywheel housing. (18) Flywheel.

General Information

The engines are electronically controlled mechanically actuated unit injector diesel engines. The 3406E is an in-line six cylinder engine with a bore of 137 mm (5.4 inch) and with a stroke of 165 mm (6.5 inch). The 3406E engine has a total displacement of 14.6 L (893 in3). The engine is configured for turbocharged air-to-air aftercooling with electronic unit injection.

The electronic control system was designed to provide electronic governing, automatic fuel ratio control, torque rise shaping, injection timing control, and system diagnostics. Additional benefits such as PTO Governor, Idle Shutdown Timer and Data Link provide for additional engine economy, and serviceability.

The Electronic unit injector system eliminates many of the mechanical components of an in-line pump system. This system also provides increased control of the timing control and of the fuel air ratio control. The timing advance is achieved by the precise control of the injector timing. The engine rpm is controlled by adjusting the duration of the injection. A special pulse wheel provides information to the electronic control module for the detection of the cylinder position and of the engine rpm.

The engine has built-in diagnostics in order to ensure that all of the components are operating properly. In the event of a system component failure, the operator will be alerted to the condition by the “Check Engine” light. A Caterpillar service tool can be used to read the numerical code of the faulty component or of the condition. Intermittent faults are logged and the information is stored in the memory.

Starting the Engine

The Electronic Control Module (ECM) will automatically provide the correct amount of fuel that is necessary to start the engine. The throttle should not be held while the engine is being cranked. At temperatures below 0°C (32°F), starting fluid may need to be sprayed into the air cleaner inlet. If the engine fails to start in 30 seconds, the starter switch should be released. The starter motor should be allowed to cool for two minutes before being used again.


Excessive ether (starting fluid) can cause piston and ring damage. Use ether for cold weather starting purposes only.

Cold Mode Operation

The engine control system performs a cold start strategy for the correct warm-up time after a cold engine start. The temperature for a cold engine start is less than 18°C (64°F). This cold start strategy is called cold mode. After being activated, this cold mode will remain active until the coolant temperature rises above 18°C (64°F) or until the engine has been running for 12 minutes. Cold mode will also vary the fuel injection amount, the timing for the maximum start-up, and the timing for the control of white smoke. The time that is necessary for the engine to achieve the normal mode of operation is usually less than the time that is required for a walk-around inspection of the engine.

Customer Specified Parameters

The engine is capable of being programmed for several customer specified parameters. Refer to System Operation, “Glossary of Words for Electronic Control” for a complete list of the customer specified parameters. Refer to the Operation and Maintenance Manual for your machine for a brief explanation of each of the customer specified parameters.

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