If you have a Caterpillar® diesel engine, also refer to your Caterpillar® Diesel Engine Operation & Maintenance Manual for starting procedure.

For vehicles with the DURAMAX™ diesel engine, also see Starting the DURAMAX™ Diesel Engine

To make starting easier in cold weather (below 32°F or 0°C), the proper viscosity engine oil should be used. See Engine Oil . It's also best to heat the engine oil first. You can do this by using an engine coolant heater.

Notice: If you ever need to have your vehicle towed, see the part of this manual that tells how to do it without damaging your vehicle. See Towing Your Vehicle .

If you have to restart the engine while the vehicle is moving, you'll first have to shift the automatic transmission to NEUTRAL (N). This safety feature prevents starting the engine when the transmission is in a drive gear.

If you have a Caterpillar® diesel engine, see your Caterpillar® Diesel Engine Operation & Maintenance Manual.

1. Set the parking brake and shift to NEUTRAL (N) or PARK (P).
2. Turn the ignition key to OFF.

If your vehicle has a two-speed axle, see Two-Speed Rear Axle Electric Shift Control

Because the diesel engine uses compression ignition, it is harder to start in cold weather than a gasoline engine. The air intake heater and use of the proper engine oil, optional engine coolant heaters and optional ether injection systems help cold weather starting. See the Caterpillar® Diesel Engine Operation & Maintenance Manual for more information.

Notice: The diesel engine has an electric air intake heater system which reduces white smoke and helps start the engine in cold weather. Do not spray starting fluid into the air intake where it can contact the heater elements.

Several factors affect how quickly your diesel engine warms up. These can include outside temperature, engine load, idle time and your vehicle's option content. Your vehicle may be equipped with some features that can help the engine reach operating temperature sooner. Some of these features are discussed below.

Also, remember that an automatic transmission adds heat to the cooling system through the heat exchanger in the radiator. Because of this, vehicles equipped with automatic transmissions are often able to retain engine coolant heat better than manual transmission vehicles.

See your Caterpillar® Operation & Maintenance manual for additional diesel engine warm-up information.

Your check gages light will come on if the system senses high engine temperature or low engine oil pressure. If high engine temperature or low engine oil pressure is detected, you will also hear a tone alarm at two beats per second. The alarm and the light will remain on until the condition is fixed. If the engine temperature or oil pressure condition worsens, the tone alarm will go to five beats per second.

If the system senses low engine coolant, the five beat per second alarm and the low coolant warning light will come on.

The five beats per second tone alarm means that your engine will shut down in approximately 25-30 seconds. There is also an engine shutdown light to indicate that the engine will shut down. See Engine Shutdown Warning Light

Pull off the road and shut off the engine. Don't start it until the reason for the problem is known, and the problem is fixed. If the engine shuts down when you are still in traffic, you can restart the engine and get another 25-30 seconds of operation. Do this only if you have to, since there is a problem that can harm the engine if it isn't fixed. Engine automatic shutdown, for gasoline engines, requires activation by your dealer.

Your vehicle has both automatic and manual high idle capabilities.

Automatic High Idle System (Diesel Engines)

The automatic high idle feature will engage whenever you start your vehicle and the engine is below the preset operating temperature. This will help decrease engine warm-up time.

Idle speed will then return to normal under any of the following conditions:

Manual High Idle System

If your vehicle has this feature, the manual high idle switch is located in the instrument panel switchbank.

This system can be used to increase your engine idle speed whenever the following conditions are met:

The manual high idle feature is activated by pressing the switch on the instrument panel. When the switch is pressed again, or any of the previous conditions are not met, manual high idle will be deactivated.

The manual high idle has been preset at the factory. Your dealer may change the setting to fit your needs.

For vehicles with Caterpillar® diesel engines, manual high idle can be used to set any desired high idle speed.

To set a new temporary engine idle speed:

1. Make sure all of the previously described conditions are met.
2. Press the accelerator pedal to the desired engine speed.
3. Momentarily press the manual high idle switch.

The temporary high idle speed will be set. This new high idle rpm level will be remembered by the system until either the ignition is turned to OFF or a new high idle speed is set.

If your vehicle is equipped with this feature, there is an exhaust restrictor valve located in the exhaust stream. The valve closes to provide back pressure to the engine for the purpose of warming the engine quickly.

The exhaust restrictor operates:

On vehicles equipped with a diesel engine exhaust brake, the exhaust brake switch must be on. The indicator in the exhaust brake switch will be lit when the exhaust restrictor is active. The exhaust brake indicator light in the center of the instrument panel will also be lit whenever the exhaust restrictor is active.

When the engine coolant temperature is below 149°F (65°C) and the outside temperature is below 50°F (10°C), the exhaust restrictor will come on within 45 seconds of starting the engine. After running the engine for an additional 45 seconds, the engine idle will increase.

The exhaust restrictor will shut off and engine idle will return to normal once the engine is warmed up, or the transmission is shifted into range.