Cadillac BLS Owner's Manual

Contents

Cadillac BLS Owner's Manual Manual pdf 148 page image

148 Starting and drivingAll-wheel drive (AWD) 3Essentially, the system consists of a PTU(Power Take off Unit), propeller shaft, RDM(Rear Drive Module which contains an elec-tronically controlled plate clutch, final drivegear and differential) and driveshafts. Thissystem enhances driving characteristicsand stability. The system is always activeand cannot be deactivated. It workstogether with the ESP system and theengine and transmission control modules.When driving at a constant speed, approx.95% of the torque is distributed to the frontwheels and approx. 5% to the rear wheels.The torque is distributed steplessly andinstantaneously between the front and rearwheels, depending on the driving condi-tions. If the car is fitted with eLSD (electron-ically controlled plate clutch between therear wheels), the torque can also be distrib-uted individually to the relevant rear wheel.For optimum system function, the car’styres should not have varying degrees ofwear.When the AWD system requires service,the following message is shown on the DIC:When the service message is displayed,the AWD system may have limited func-tionality (or be completely disabled insome cases, i.e. the car switches tofront-wheel drive). Contact a workshopfor information. We recommend that youcontact an authorised Cadillac work-shop.Traction ControlSystem (TCS)Anti-spin systemHow the system worksThe Traction Control System (TCS) isdesigned to reduce wheelspin and so togive the car the best possible tractive force,together with enhanced driveability andgreater stability.The TCS system uses information from theABS system’s wheel speed sensors todetermine whether any wheel is spinning. Ifany wheel is spinning, this is reduced on all-wheel drive cars initially by changing thetorque distribution, secondly by reducingthe engine torque, and thirdly with the aid ofthe wheel brakes. On front-wheel drive cars,wheelspin is reduced initially by reducingthe engine torque, and secondly with the aidof the wheel brakes.The advantages of the TCS system aremost apparent when road surface friction isService XWD.WARNINGThe TCS system improves stability anddriveability during normal driving, but itmust not be regarded as an opportunity toincrease the speed. The same precau-tions as normal for safe cornering anddriving on slippery roads must beadopted.460_OM_MY09.book Page 148 Wednesday, April 2, 2008 10:32 AM