[Orange Crush]

NISSAN TITAN 4WD SYSTEM EXPLAINED

The 4WD system is a shift on the fly system allowing the choice between 2WD, 4H, and 4LO. It uses a free running hub design that allows engaging and disengaging from 2wd to 4H at speeds of up to 60 M.P.H.

Nissan is now offering an optional locking rear differential that is an electronically activated switch -on-demand locking rear differential that will send an equal amount of power to each wheel at all times for extreme off road conditions.

During normal driving you have two open differentials working for you (front & rear). The center is a locked transfer case (2WD for normal driving conditions or manually selected 4WD) which is why this is a part-time 4WD system. Open differentials are extremely reliable and require very little maintenance.

If one wheel begins to slip, the open differentials begin to send all available power to that one wheel. Normally, this would be very bad. This is when the Active Brake Limited Slip (ABLS) traction control system (TCS) takes over. ABLS, applies brakes selectively to a slipping wheel. This braking action literally fools the differentials into sending power everywhere except the slipping wheel.

When you are in 2WD, this only will send power left to right on the rear drive axle.

There is one thing to be careful of in this condition, there is a second part of the TCS that can be hazardous if you are not paying attention. This is the engine speed limiter. This combines the braking action of ABLS with a rev limiter. Your engine speed will be cut back. This allows for controlled forward movement but it will be slow. The danger with this is if it engages when you are trying to pull into fast moving traffic or encounter unexpected loose gravel and slippery surfaces.

The other part of this system is the VDC or Vehicle Dynamic Control. VDC will selectively apply brakes and throttle to prevent understeer or oversteer. This is a rather amazing system and does an incredible job of giving the driver control of the vehicle. Understeer is responsible for a large number of rollovers and oversteer is very common on icy surfaces. The Titan will allow you the option to turn off the VDC. The only reason to turn this off is if you are off road and want to be able to slide sideways.

Active Brake Limited Slip (ABLS)

When ABS wheel-speed sensors detect a loss of traction in one or more wheels, braking force is applied to that wheel to help slow it down. This redirects power to the wheels with better traction.

Traction Control System (TCS)

• The traction control system reduces torque to the drive wheels by altering injector pulse and controlling the Electronic Throttle Control (ETC) motor. If necessary, the brakes are also pulsed via the ABS control unit and hydraulic unit to reduce slipping.

–For injector pulse and ETC functions, the ECM receives wheel slip information from the ABS control unit through the Controller Area Network (CAN) bus.

TCS operates at all speeds and limits drive-wheel slip (wheel spin) under most conditions, improving driver control of the vehicle in slippery conditions as well as on dry surfaces if throttle is over-applied.

Vehicle Dynamic Control (VDC)with TCS and ABS

• The system integrates ABS and TCS with additional cornering controls.

• The VDC control functions (integrated into the ABS control unit) monitor the input from steering wheel angle, vehicle speed, wheel speed, G-force and yaw rate.

• When vehicle stability is affected by road conditions or the need to make an emergency maneuver, the system helps to maintain optimum speed at each wheel.

• The system controls engine output by reducing fuel and throttle opening, and provides individual braking control for each wheel to reduce or prevent skidding.

VDC changes engine power and/or applies the brakes individually as necessary to help stabilize the vehicle in severe turning situations. VDC helps enhance performance in emergency avoidance maneuvers, helps improve vehicle directional stability, and helps provide improved control even on slippery road surfaces.

Note:VDC not available with locking rear differential.