Traction Control System - Service Tips
Article No.97-24-8
11/24/97
STEERING - TRACTION CONTROL SYSTEM - SERVICE TIPS
FORD:
1998 CROWN VICTORIA
LINCOLN-MERCURY:
1997-98 MARK VIII
1998 GRAND MARQUIS, TOWN CAR
This TSB article is being republished in its entirety to include additional vehicles and the 1998 model year.
ISSUE:
The Traction Control System (TCS) is standard on all 1997-98 Mark VIII, 1998 Town Car, 1998 Grand Marquis and 1998 Crown Victoria vehicles. The TCS aids in maintaining stability and maneuverability on slippery surfaces at all vehicle speeds by detecting and controlling wheel spin.
ACTION:
Refer to the following text for an overview, system operation and characteristics review of the TCS.
OVERVIEW
The TCS uses many of the electronic and mechanical components from the Anti-lock Brake System (ABS) and the Powertrain Control Module (PCM).
The wheel speed sensors from the ABS are used to monitor wheel spin. Excessive wheel spin is controlled by using a combination of:
^ Brake application of one or both driven wheels
^ Reduction of engine power via the PCM (spark retard and fuel control)
The TCS is automatically active when the vehicle is started. The TCS can be deactivated by referring to the appropriate Page in the appropriate Owner's Guide. The TCS will reactivate automatically after each key cycle.
SYSTEM OPERATION
^ The wheel speed sensors allow excess rear wheel spin to be detected by the Traction Control portion of the ABS module. Any excessive wheel spin is then controlled automatically
^ The TCS will first rapidly apply and release the rear brakes to one or both wheels to prevent them from spinning during acceleration
^ If wheel spin is still occurring, TCS will reduce engine power output by retarding the ignition, then reducing fuel to the injectors until wheel spin is no longer detected. Engine output may be reduced by as much as 75%
^ This process is very sensitive and reacts quickly to driving conditions
^ The rear wheels "search" for optimum traction several times per second and adjustments are made accordingly
^ The engine will not "rev-up" when you push the accelerator pedal when TCS is in operation. This is normal behavior
NORMAL OPERATING CHARACTERISTICS
When the TCS is controlling wheel spin, the following sounds or sensations may be felt by the driver:
^ The TCS lamp on the gauge cluster (just below the tachometer) will illuminate for the duration of the traction control operation or 6 seconds (refer to Page 12 of the 1997 Mark VIII Owner's Guide)
^ An electric motor sound will be heard, signifying ABS pump motor operating
^ A "clicking" sound will be heard from the ABS hydraulic control unit
^ A "thumping" noise may be heard from the rear of the vehicle, signifying the rear brakes cycling
^ The power output of the engine will seem to be low (even with the throttle fully open) as the TCS retards the spark and reduces fuel to the engine - engine power output may be reduced up to 75%, if necessary, to control wheel spin
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 97-6-4
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 206000, 301000, 614000, 614500