halderman ch108 lecture
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© 2011 Pearson Education, Inc.All Rights Reserved
Automotive Technology, Fourth EditionJames Halderman
ELECTRONIC STABILITY CONTROL SYSTEMS
108
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ObjectivesObjectives• The student should be able to:
– Prepare for Brakes (A5) ASE certification test content area “F” (Antilock Brake System Diagnosis and Repair).
– Discuss how an electronic stability system works.
– List the sensors needed for the ESC system.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ObjectivesObjectives• The student should be able to:
– Explain how the ESC system helps keep the vehicle under control.
– Describe how a traction control system works.
– List the steps in the diagnostic process for ESC and TC system faults.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
THE NEED FOR THE NEED FOR ELECTRONICELECTRONIC
STABILITY CONTROLSTABILITY CONTROL
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• Purpose and Function– Electronic stability control (ESC) is system
designed to help drivers keep control of their cars
– Helps prevent run-off-road crashes and rollovers
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC has the following features:
1. Applies individual brakes to maintain directional stability.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC has the following features:
2. Uses sensors to determine if vehicle is not under control.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC has the following features:
3. Uses steering wheel position sensor to determine intended direction.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC has the following features:
4. Operates at all vehicle speeds except low speeds.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC applies individual brakes if either of
these conditions occur:• Oversteering: rear of vehicle moves outward
or breaks loose– Can result in loss of control
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC applies individual brakes if either of
these conditions occur:• Understeering: front of vehicle continues
straight when turning
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-1 The electronic stability control (ESC) system applies individual wheel brakes to keep the vehicle under control of the driver.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– NOTE: When the brakes are applied during
these corrections, a thumping sound and vibration may be sensed.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC lamp—called telltale lamp—remains on
as long as malfunction exists when ignition is on
– Telltale lamp flashes to indicate when ESC system is operating
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– Some manufacturers install switch to
temporarily disable ESC– Feature useful on certain occasions
• When a vehicle is stuck in sand or gravel
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– Feature useful on certain occasions
• When vehicle is being operated on racetrack
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
The Need for Electronic Stability The Need for Electronic Stability ControlControl
• System Requirements– ESC automatically turns back on when
ignition is turned off and then on again
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
FEDERAL MOTOR FEDERAL MOTOR VEHICLEVEHICLE
SAFETY STANDARDSAFETY STANDARD(FMVSS) NO. 126(FMVSS) NO. 126
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Federal Motor Vehicle Safety Federal Motor Vehicle Safety Standard (FMVSS) No. 126Standard (FMVSS) No. 126
• FMVSS, Electronic Stability Control Systems, requires all passenger vehicles with gross vehicle weight rating less than 10,000 pounds to have ESC systems by 2012 model year
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Federal Motor Vehicle Safety Federal Motor Vehicle Safety Standard (FMVSS) No. 126Standard (FMVSS) No. 126
• ESC system must meet these requirements:1. Must be able to apply all four brakes
independently.• Acceleration
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Federal Motor Vehicle Safety Federal Motor Vehicle Safety Standard (FMVSS) No. 126Standard (FMVSS) No. 126
• ESC system must meet these requirements:2. Must be programmed to work during all
phases of driving. • Coasting
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Federal Motor Vehicle Safety Federal Motor Vehicle Safety Standard (FMVSS) No. 126Standard (FMVSS) No. 126
• ESC system must meet these requirements2. Must be programmed to work
during all phases of driving. • Deceleration (including braking)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
SINE WITH DWELL SINE WITH DWELL TESTTEST
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
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Sine with Dwell TestSine with Dwell Test• Standardized test to check ESC system
functionality is sine with dwell (SWD) test– Vehicle driven at 50 mph (80 km/h) on
curved course– Vehicle is held in straight ahead position for
0.5 second (500 milliseconds)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Sine with Dwell TestSine with Dwell Test• Standardized test to check ESC system
functionality is sine with dwell (SWD) test– Vehicle is then steered back onto curved
section of road• Test designed to force vehicle ESC
system to respond
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-2 The sine with dwell test is designed to test the electronic stability control (ESC) system to determine if the system can keep the vehicle under control.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
NAMES OF VARIOUSNAMES OF VARIOUSESC SYSTEMSESC SYSTEMS
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Names of Various ESC SystemsNames of Various ESC Systems• Every manufacturer has its own name
for the ESC system• Some examples include the following:
– BMW: Dynamic Stability Control (DSC)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Names of Various ESC SystemsNames of Various ESC Systems• Some examples include the following:
– Chrysler: Electronic Stability Program (ESP)– Ford: AdvanceTrac and Interactive Vehicle
Dynamics (IVD)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Names of Various ESC SystemsNames of Various ESC Systems• Some examples include the following:
– General Motors: StabiliTrak (except Corvette—Active Handling)
– Jeep: Electronic Stability Program (ESP)– Toyota: Vehicle Dynamics Integrated
Management (VDIM) with Vehicle Stability Control (VSG)
?
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SENSORSESC SENSORS
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Steering Wheel Position Sensor
– May also be called a hand-wheel position sensor
– Provides computer with signals related to steering wheel position, speed, and direction
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-4 The hand-wheel position sensor is usually located at the base of the steering column.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-5 Hand-wheel (steering wheel) position sensor schematic.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Vehicle Speed Sensor
– Used by Electronic Brake Control Module to help control suspension system
– Vehicle speed (VS) sensor is magnetic sensor
– VS sensor generates analog signal whose frequency increases as speed increases
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-6 The VS sensor information is transmitted to the EBCM by Class 2 serial data.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Provides suspension control module with feedback regarding cornering forces
– This type of sensor called G-sensor
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Letter “G” stands for gravity– Information processed by suspension
control module
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Module provides appropriate damping on inboard and outboard dampers during cornering events
– This sensor can be stand-alone unit or combined with yaw rate sensor
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Typically mounted in passenger compartment:
• Under front seat
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Typically mounted in passenger compartment:
• In center console
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Lateral Acceleration Sensor
– Typically mounted in passenger compartment:
• On package shelf
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-7 A schematic showing the lateral acceleration sensor and EBCM.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Yaw Rate Sensor
– Provides information to suspension control module and EBCM
– Information used to determine how far vehicle has deviated from intended direction
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC SensorsESC Sensors• Yaw Rate Sensor
– Can be stand-alone unit or combined with lateral acceleration sensor
– Typically mounted under front seat, in center console, or on rear package shelf
– Sensor sets DTC codes
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-9 Yaw rate sensor showing the typical locations and schematic.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
TRACTION CONTROLTRACTION CONTROL
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Purpose and Function
– Traction control (TC) can be separate or combined with ESC system
– TC allows ABS system to control wheel spin during acceleration
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Purpose and Function
– When tires lose traction during acceleration it’s called positive slip
– Low-speed (up to 30 mph) TC uses braking system to limit positive slip
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-10 Typical traction control system that uses wheel speed sensor information and the engine controller (PCM) to apply the brakes at lower speeds and also reduce engine power applied to the drive wheels.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Purpose and Function
– TC uses same wheel speed sensors as ABS– Requires additional programming in control
module
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Purpose and Function
– TC also requires• Additional solenoids in hydraulic modulator
– Needed to isolate non-drive wheels from drive wheels when braking is needed to control wheel spin
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Purpose and Function
– TC also requires• Pump and accumulator to generator and
store pressure for TC braking– TC works on front-wheel-drive and rear-
wheel-drive vehicles
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Main controller for TC system includes one of following:
• Body control module (BCM)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Main controller for TC system includes one of following:
• Powertrain control module (PCM)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Main controller for TC system includes one of following:
• Antilock brake system (ABS) controller
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Controller uses inputs from several sensors• Throttle position (TP) sensor
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Controller uses inputs from several sensors• Wheel speed sensor (WSS)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Controller uses inputs from several sensors• Engine speed (RPM)
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • System Components
– Controller uses inputs from several sensors• Transmission range switch
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Traction Control Operation
– Outputs of TC system can include one or more of the following:
• Retard ignition timing to reduce engine torque
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Traction Control Operation
– Outputs of TC system can include one or more of the following:
• Decrease fuel injector pulse-width to reduce fuel delivery to reduce engine torque
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Traction Control Operation
– Outputs of TC system can include one or more of the following:
• Reduce amount of intake air if engine is equipped with an electronic throttle control (ETC)
– Reducing intake air will reduce engine torque
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Traction Control Operation
– Outputs of TC system can include one or more of the following:
• Upshift the automatic transmission/transaxle– Shifting into higher gear reduces torque
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction Control Traction Control • Traction Control Operation
– Most TC systems can reduce positive wheel slip at all speeds
• Most use accelerator reduction and engine power reduction to limit slip before applying brakes
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-11 Wheel speed sensor information is used to monitor if a drive wheel is starting to spin.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Sequence of Events when TC system
Engaged1. Engine torque reduced for drive wheels.2. Brakes applied to slow or stop wheel
spinning.3. Low traction or TC warning light
illuminated on dash.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-12 A traction control or low traction light on the dash is confusing to many drivers. When the lamp is on or flashing, it indicates that a low traction condition has been determined and the traction control system is working to restore traction. A flashing traction dash light does not indicate a fault.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Traction Active Lamp
– “TRAC CNTL” indicator light or “TRACTION CONTROL ACTIVE” message flashes on instrumentation when TC engaged
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Traction Active Lamp
– Message alerts driver to loss of traction– Message does not indicate a fault in system
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Traction ControlTraction Control• Traction Deactivation Switch
– Many vehicles have dash-mounted TC deactivation switch
– Indicator light shows when system is on or off
?
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DIAGNOSISESC/TC DIAGNOSIS
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• ESC and TC systems use some of same
sensors and controllers• Diagnosis is about the same for both• Follow recommended procedures in
service information
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 1: Verify customer concern.– STEP 2: Perform thorough visual inspection.
• Check tires are same size and tread depth
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 2: Perform thorough visual inspection.• NOTE: Use a spare tire on the drive wheel
could cause the traction control and/or ESC amber warning light to flash because the controller is seeing that the smaller tire is rotating faster than the other side.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 3: Check service information for specified procedure to retrieve DTCs.
• Check related technical service bulletins
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 3: Check service information for specified procedure to retrieve DTCs.
• Most vehicles require factory-brand scan tool
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
Figure 108-13 The use of a factory scan tool is often needed to diagnose the ESC system.
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 4: Following troubleshooting procedure specified to fix root cause of problem.
• Steps usually include checking all or many of the following:
– Brake fluid level
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 4: Following troubleshooting procedure specified to fix root cause of problem.
• Steps usually include checking all or many of the following:
– Wheel speed sensor resistance
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 4: Following troubleshooting procedure specified to fix root cause of problem.
• Steps usually include checking all or many of the following:
– Fault with base brake system
108 ELECTRONIC STABILITY CONTROL SYSTEMS
Automotive Technology, Fourth EditionJames Halderman
© 2011 Pearson Education, Inc.All Rights Reserved
ESC/TC DiagnosisESC/TC Diagnosis• Usual procedure follows these steps:
– STEP 5: Repair the fault.– STEP 6: Road test the vehicle under same
conditions that caused the fault.