Off car Exercises
Think about ABS Repair:
Misconceptions, The ABS system should be simple and robust with module/ECU/ Controller almost never giving any trouble.
Below are some possible causes for damaging an ECU.
1-Spiked by careless welding,i,e. MIG welding without disconnecting the battery. TRUE
2-Enclosure seal damaged and with obvious sing of water ingress.TRUE
3-Obvious sings of mechanical damage to the enclosure.TRUE
4-Faults are much more likely to be with connections or sensors.TRUE
Discuss how these ECU issues should be incorporated into diagnostic practices to test an ABS systems?
When the ABS processes the signals to determine the acceleration and the slip of wheels. The control signals to the hydraulic modulator which brake pressure in the system. The ECU includes a test monitor and a warning function. If the vehicle is in use the antibraking system monitors itself and if a fault is found will switch itself off and the ABS warning in the dash board will remain on in show that there is a fault in the system.
ABS Wiring and Operation
Lets review the ABS system to remind ourselves what components are included and how they should work.
Fill in the blank with the name of the part?
1=Disc rotors
2=Wheel speed sensor
3=Sensor ring
4=Hydrolic control unit
5=Master cylinder
6= Calliper
7=Brake booster
ABS (ANTI-LOCK BRAKE SYSTEM FOR RHD)
Wiring Diagram Practice
1-Using the wiring diagram in the workshop manuals identify the wheel speed sensors and list their wire colours for each sensor?
Front Right (white-black)
Front Left (green- red)
Rear Left (blue-pink)
Rear Right (yellow-brown)
2-On the ABS wheel sensor what is the reason for the braded wire?
The reason for the braded wire or shielding is for protection from radio interference or back EMF.
3-Identify and list all the fuses used by the ABS circuit?
Mane fuse 50A(/-01)
IG key 50A
ABS 40A (/-01)
Engine 15A
4-Identify the earth's for the ABS control unit and ABS motor their wire colours what pine numbers?
ABS motor (B)3 ABS control unit pin 1E(B) pin 1F(B) Junction 4)
5-On the wiring diagram for the ABS actuator, identify which solenoids control which wheel cylinder.
Then note the wire colours and pin numbers?
1-Front Right Wheel?
pin number (A 10)
wire colour (L-G)
2- Front Left Wheel?
pin number (1 B)
Wire colour (Y-R)
3-Rear Left Wheel?
pin number(1 D)
Wire colour (Brown)
4-Rear Right Wheel?
pin number(1 A)
Wire colour(Pink)
Using the picture on the next page as a guide, which of the following gives the correct condition of the inlet solenoids valves under normal braking?
A: inlet valve open outlet valve open
B: (YES) inlet valve open outlet valve closed
C: inlet valve closed outlet valve open
D: inlet valve closed outlet valve closed
Using the picture on the next page as a guide, which of the following gives the correct condition of the inlet and outlet solenoids valves when the ABS is operating to reduce wheel brake pressure?
A: Inlet valve Open Outlet valve Open
B: Inlet valve open Outlet valve Closed
C: (YES) Inlet valve Closed Outlet valve Open
D: Inlet valve Closed Outlet valve Closed
Using the picture as a guide which of the following gives the correct condition of the inlet and outlet solenoids valves when the ABS is operating to hold brake pressure?
A: Inlet valve open Outlet valve Open
B: Inlet valve Open Outlet valve Closed
C: Inlet valve Closed Outlet valve Open
D: (YES) Inlet valve Closed Outlet valve Closed
Using the picture as a guide, which of the following gives the correct condition of the inlet and outlet solenoids valve when the ABS is operating to increase wheel brake pressures?
A: Inlet valve Open Outlet valve open
B: (YES)inlet valve open Outlet valve closed
C: Inlet valve Closed Outlet valve Open
D: Inlet valve Closed Outlet valve Closed
In the four cases above state when the ABS motor will be working?
The ABS motor starts working in pressure reduction case which will return fluid to master cylinder reservoir.
On the graph below draw a digital signal that switches 5 volts every 2 seconds.
Mark volt and time scales on graph that will show the signal well.
Mark volt and time scales on graph that will show the signal well.
On the graph below draw an analogue signal with a frequency of 0.5 Hz and a maximum of +3 volts. Mark volt and time scales on graph that will show the signal well.
ABS Demonstrators
Local the wiring diagram for your demonstrator vehicle. Find the ABDS wheel speed sensor pin out connections to the ECU on the wiring diagram and the demonstrator. Record which ECU wires go to which wheel speed sensors?
Left front ECU Pin # 2 0 and 2 P
Left rear ECU Pin # 2 R and 2 Q
Right front ECU Pin # 2 N and 2 M
Right rear ECU Pin # 2 S and 2 T
By looking at the wiring diagram, what type of speed sensor is this?
It is Inductive type sensor.
Describe how it works:
When the tooth of the ring gets closes to the sensor it induces voltage if the tooth gets away from the sensor it inducts a voltage to the sensor in opposite direction Ac voltage.
Locate an oscilloscope. Turn it on and set it up to be fully operational. What
oscilloscope are you using? Tektronix TD 100 IB
oscilloscope are you using? Tektronix TD 100 IB
Record a waveform for each wheel speed sensor in the boxes below. Note voltage per division and time per division for each.
Which wheel is this? L F
Which wheel is this? L R
Which wheel is this? R R
Which wheel is this? R L
Are all the waveforms exactly the same? No. Discuss what are the differences, and what can cause these differences between the waveforms?
The waveforms are different in voltage amplitude and frequency these could be the result of different made and model of the wheel speed sensor and also could be the sensor gap which is critical for the strength of the signal.
With the wheel speed sensors spinning, measure AC volts with a multi-meter and record here?
Left front 3.665v
Left rear 2.618v
Right front 4.412v
Right rear 4.910v
Left rear 2.618v
Right front 4.412v
Right rear 4.910v
Can a multi-meter be as accurate in finding problems with the wheel speed sensors as an oscilloscope? No
Discuss what the oscilloscope could find that the multi-meter cannot find and why?
Oscilloscope is very accurate to describe the function of wheel speed sensor in term of waveform. Multi-meter is good for voltage drops but for wheel speed pick up any missing tooth because of the speed.
ABS Relays
Record the name of the relay or switch that powers up the ABS ECU?
K 38
K 38
Record the name of the relay or switch that powers up the ABS pump?
K 100
K 100
Record the name of the relay or switch that powers up the ABS HCU solenoids?
K 39
K 39
What is the ECU pin number for the wire that brings in the power to the ABS ECU?
J 2
J 2
What is the ECU pin number, or other number, for the wire that controls the relay for the ABS ECU?
85-86
85-86
What is the pin number for the wire that brings in the power to the ABS Pump?
30-87
30-87
What is the pin number, or other number, for the wire that controls the relay for the ABS Pump?
85-86
85-86
Relay waveform: Capture a waveform that shows both the control circuit change when it turns on the relay, and the power switching on to power something in the ABS system. (Use an oscilloscope with two channels to capture this pattern. You may have to carefully set the trigger to capture this.) Record the waveform below with the time and volts per division, and explain what you are measuring?
Explain with arrows what is happening in the waveform above?
Point A = Battery voltage from key being turned on
B = grounding by ECU earth triggered
C = voltage going back to battery voltage from being on to off
D = Zero voltage switched off
E = going to zero voltage
g = time log, this is the time delay or different between the two pins
B = grounding by ECU earth triggered
C = voltage going back to battery voltage from being on to off
D = Zero voltage switched off
E = going to zero voltage
g = time log, this is the time delay or different between the two pins
5 volts per division in channel one and two. 100 ms per division. 10 Hz
ABS Pump Relay waveform: Capture a waveform that shows both the control circuit change when it turns on the relay, and the power switching on to power the ABS Pump. (Use a oscilloscope with two channels to capture this pattern. You may have to carefully set the trigger to capture this.) Record the waveform below with the time and volts per division?
Explain with arrows what is happening in the waveform above?
Point A = battery. Voltage
B = grounded by ECU.
C = has turned on by pin.
D = When pin has been grounded off
E = Time log
F = When the pin is being turned on at the same time the other pin is turned off.
B = grounded by ECU.
C = has turned on by pin.
D = When pin has been grounded off
E = Time log
F = When the pin is being turned on at the same time the other pin is turned off.
5 volts per division channel one and two. 500 ms per division.
Observe what happens during the ABS Self Test when you first turn the key on. Watch the warning lights, and observe power at the wires with the oscilloscope. Then discuss
what is happening in the ABS system during the Self Test?
When the ignition key first turn on we can see the warning light come on and little while later the motor starts and we can hear the solenoids come on as it test the ABS-the oscilloscope shows zero voltage when the key is off on both pins of the relays but only one resister a charge in voltage (0-12v) when the key is turned off. The warning light comes on that same pattern goes down as it is earth triggered and the other came up as is turned on to start work the first back to 12v and switch the second one off so it is going back to zero volts.
Create a fault in the system by slowing down a wheel speed sensor of safely shorting out an inductive wheel speed sensor while you are applying the brakes. (Don’t short out a Hall Effect or Magneto-Resistive sensor) As you are applying the brakes, notice if the ABS pump turns on, solenoids turn on, or if the hydraulic pressure changes in one of the brake circuits and shows up on the pressure gauge. Discuss what is happening below?
When the wheel starts to slow down a wheel speed sensor detects this and detects to lock up then the ABS kicks in too prevent the lock up and slow down properly the ECU thinks the driver is losing stability and steerability and attemps to avoid a lock up.
Catch an oscilloscope pattern when an ABS solenoid has actuated?
What is the pin and name of the solenoid? How did you do it?
When using a wiring diagram provided to find solenoids and follow their wires to know which one is which then pick one and use the wire colour to gather from wiring diagram and then looked back probed the signal i connected the position wire of the oscilloscope to it and negative to earth.
Draw the oscilloscope pattern below?
On Car Exercises
On the vehicle that you have been assigned identify the following components to your tutor?
1-Wheel speed sensor
2- ABS control unit
3- ABS modulator
4- ABS pump motor
5-Parking brake switch
6-ABS master cylinder
7-Brake fluid level switch (if fitted)
8-RPM sensor
10-Foot brake sensor
11-Brake booster
12-Main ABS control unit fuse
On the vehicle that you have been assigned identify the following components to your tutor?
1-Wheel speed sensor
2- ABS control unit
3- ABS modulator
4- ABS pump motor
5-Parking brake switch
6-ABS master cylinder
7-Brake fluid level switch (if fitted)
8-RPM sensor
10-Foot brake sensor
11-Brake booster
12-Main ABS control unit fuse
ABS Wheel Speed Sensor
On the vehicle that you have been assigned does it use analogue or digital wheel sensors?
Inductive Type Analogue
Inductive Type Analogue
How did you conclude that the wheel sensor were analogue or digital?
It is an inductive type analogue sensor as we got time wave pattern on the oscilloscope.
It is an inductive type analogue sensor as we got time wave pattern on the oscilloscope.
Measure the air gap for each wheel sensor?
State the air gap and visual condition of each wheel sensor?
Front Right 0.25 mm the exciter ring has little dirt on it.
Front Left 0.203 mm the same as above
Rear Right 0.406 Clean and tidy both the exciter and the sensor.
Rear Left 0.406 mm Same as above.
Front Left 0.203 mm the same as above
Rear Right 0.406 Clean and tidy both the exciter and the sensor.
Rear Left 0.406 mm Same as above.
Using an oscilloscope connect it to a wheel sensor and record the pattern shown, if the sensor is a Analogue sensor then just connect then probe and spin the wheel. If the sensor is digital you will need to have the ignition on before you turn the wheels?
Is this pattern an analogue or digital pattern?
An analogue pattern.
An analogue pattern.
Using the frequency scale on a multi-meter. Turn the wheel at proximally the same speed as in the above test. Note the frequency and compare it to the graph you drew above?
Frequency ? 156 Hz
Observation?
Both frequency and voltage are changing with the speed low speed produced low voltage signal with slow frequency higher speed produced or higher voltage signal and lighter frequency.
Using a Scan Tools
Using a scan tool go to the ABS live data screen and note all the sensors, data and what it is telling you?
(page 23 image)
1= LF when speed sensor sends signal in regard to the speed of left front wheel.
2=RF when speed sensor send siganl to the ECU about the speed of the right front wheel.
3= LR wheel speed sensor this sensor send information to the ECU about the speed of left rear wheel.
4= RR wheel speed sensor this sensor sends information to the ECU about the speed of right rear wheel.
5= brake switch sensor inactive.
6= LF hold solenoid command the solenoid is on both inlet and outlet solenoid holt the pressure constant in the system.
7= LF hold solenoid feedback the outlet valve in closed and the outlet valve open and closed it does the cycle.
8= LF release the solenoid command the outlet valve opens to release pressure in the wheels.
9= LF release solenoid feedback solenoid is hot on outlet normal braking.
10= LF hold solenoid command the solenoid is on both inlet valve closed and hold pressure.
11= LF hold solenoid feedback outlet solenoid is not on normal braking the inlet valve is open.
12= LF release solenoid command and outlet valve is opened and released pressure in that wheels.
Using the scan tool on the vehicle you have been assigned to.Go to the actuator test screen?
ACTUATION TEST
1=Left front solenoid
2=Right front solenoid
3-Left rear solenoid
4=Right rear solenoid
Test condition?
1=stop the vehicle and stop the engine.
2=shift lever to neutral press brake pedal.
3=Press ENTER key to start the test.
Electronic Transmissions and scan tools?
Abbreviations?
1=PCM= Power train Control Module.
2=TCC= Torque Converter Clutch.
3=TPS= Throttle Position Sensor.
4=ECT= Engine Coolant Temperature Sensor.
5=VSS=Vehicle Speed Sensor.
6=PSA= Transmission Range Fluid Pressure Switch Assembly.
7=TTS= Transmission Temperature Sensor.
Block Diagram
IAT Injectors
MAP Fuel pump relay
TPS Idle Air control
ECT Power train Ignition system
TFT Control Module Tarns control
VSS Oil pressure switch
Wheels Starter
Speedom Fuel injection relay
Knock Sensor
Wiring Diagram
Use the following Holden chart for questions below?
Shift Solenoids
Which Solenoids are "ON" when this vehicle is shifted into Drive and starts out in first gear?
1 -2 and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into second gear?
2 -3 and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into third gear?
off -off and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into fourth gear?
1 -2 and 1 -2
Shift Solenoids Malfunction:
If one of the solenoids came on the vehicle will be in third gear the vehicle will have very weak or very less power to move at the start but then it will be fast on flat surface.
Codes: Pick two transmission codes out of repair information and describe what the code means and what malfunction would cause the code?
Code (21)
Throttle position sensor signal circuit voltage high TP voltage greater then 4.9 volts for 2 seconds while the engine is Idling.
Code (15)
Engine coolant temprature sensor circuit voltage high engine has been running more than 60 seconds and ECT has been greater then 4.74 volts less then 33 degrees
Diagnosis
For each code listed above, discuss what tests you could run to diagnose the problem?
1st Problem Testing?
Used the scantool checked the trans at operating temperature accelerate the vehicle the vehicle to 4th gear make sure TCC is on manitor trans slip speed disply on scantool if it is greator than 100 RPM manually down shift trans into 3th gear miscellaneous test output test TCC solenod disply TCC and terms slip speed does trans slips speed greater than 100 RPM.
2nd Problem Test?
Install scantool disply engine speed and TCC slip speed operate car untill proper trans operating temperature 82 degrees - 92 degrees drive vehicle 80 - 88 KM/H with light throttle abseve trans slip speed on scantool rapidly deprss throttle check if trans slip speed is more than 100 RPM. Remove trans fluid pan check the torque cnverter clutch.
On Car Exercises
2.1 Connect a Scan Tool to the vehicle you are testing and bring up the transmisson?
Which scan tool are you using? Multi Scan.
Which vehicle are you using? Opel Vectra.
2.2 View the solenoids as the vehicle shifts up and down Record which solenoids are on in which gears?
with the shift lever in Drive or Overdrive?
First gear solenoids: off on
Second gear solenoids on off
third gear solennoids on off
furth gear solenoids off on
Veiw the Toque Converter Clutch as you safely drive the vehicle. Record when it is on or off?
Torque Converter Clutch On ?
Active when Accelerating.
Torque Converter Clutch Off?
Turns off when it is not Accelerating.
What effect does the brake padal have on the Torque Converter Clutch?
When the brake padal is applied the Torque Converter Clutch is released from the flywheel disengged.
Create Shift Chartfor your vehicle. Based on the operation of the shifting above create a shift chart that describes what solenoids are on in which gear?
Observation?
Both frequency and voltage are changing with the speed low speed produced low voltage signal with slow frequency higher speed produced or higher voltage signal and lighter frequency.
Using a Scan Tools
Using a scan tool go to the ABS live data screen and note all the sensors, data and what it is telling you?
(page 23 image)
1= LF when speed sensor sends signal in regard to the speed of left front wheel.
2=RF when speed sensor send siganl to the ECU about the speed of the right front wheel.
3= LR wheel speed sensor this sensor send information to the ECU about the speed of left rear wheel.
4= RR wheel speed sensor this sensor sends information to the ECU about the speed of right rear wheel.
5= brake switch sensor inactive.
6= LF hold solenoid command the solenoid is on both inlet and outlet solenoid holt the pressure constant in the system.
7= LF hold solenoid feedback the outlet valve in closed and the outlet valve open and closed it does the cycle.
8= LF release the solenoid command the outlet valve opens to release pressure in the wheels.
9= LF release solenoid feedback solenoid is hot on outlet normal braking.
10= LF hold solenoid command the solenoid is on both inlet valve closed and hold pressure.
11= LF hold solenoid feedback outlet solenoid is not on normal braking the inlet valve is open.
12= LF release solenoid command and outlet valve is opened and released pressure in that wheels.
Using the scan tool on the vehicle you have been assigned to.Go to the actuator test screen?
ACTUATION TEST
1=Left front solenoid
2=Right front solenoid
3-Left rear solenoid
4=Right rear solenoid
Test condition?
1=stop the vehicle and stop the engine.
2=shift lever to neutral press brake pedal.
3=Press ENTER key to start the test.
Electronic Transmissions and scan tools?
Abbreviations?
1=PCM= Power train Control Module.
2=TCC= Torque Converter Clutch.
3=TPS= Throttle Position Sensor.
4=ECT= Engine Coolant Temperature Sensor.
5=VSS=Vehicle Speed Sensor.
6=PSA= Transmission Range Fluid Pressure Switch Assembly.
7=TTS= Transmission Temperature Sensor.
Block Diagram
IAT Injectors
MAP Fuel pump relay
TPS Idle Air control
ECT Power train Ignition system
TFT Control Module Tarns control
VSS Oil pressure switch
Wheels Starter
Speedom Fuel injection relay
Knock Sensor
Wiring Diagram
Use the following Holden chart for questions below?
Shift Solenoids
Which Solenoids are "ON" when this vehicle is shifted into Drive and starts out in first gear?
1 -2 and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into second gear?
2 -3 and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into third gear?
off -off and 2 -3
Which solenoids are "ON" when this vehicle automatically shifts into fourth gear?
1 -2 and 1 -2
Shift Solenoids Malfunction:
If one of the solenoids came on the vehicle will be in third gear the vehicle will have very weak or very less power to move at the start but then it will be fast on flat surface.
Codes: Pick two transmission codes out of repair information and describe what the code means and what malfunction would cause the code?
Code (21)
Throttle position sensor signal circuit voltage high TP voltage greater then 4.9 volts for 2 seconds while the engine is Idling.
Code (15)
Engine coolant temprature sensor circuit voltage high engine has been running more than 60 seconds and ECT has been greater then 4.74 volts less then 33 degrees
Diagnosis
For each code listed above, discuss what tests you could run to diagnose the problem?
1st Problem Testing?
Used the scantool checked the trans at operating temperature accelerate the vehicle the vehicle to 4th gear make sure TCC is on manitor trans slip speed disply on scantool if it is greator than 100 RPM manually down shift trans into 3th gear miscellaneous test output test TCC solenod disply TCC and terms slip speed does trans slips speed greater than 100 RPM.
2nd Problem Test?
Install scantool disply engine speed and TCC slip speed operate car untill proper trans operating temperature 82 degrees - 92 degrees drive vehicle 80 - 88 KM/H with light throttle abseve trans slip speed on scantool rapidly deprss throttle check if trans slip speed is more than 100 RPM. Remove trans fluid pan check the torque cnverter clutch.
On Car Exercises
2.1 Connect a Scan Tool to the vehicle you are testing and bring up the transmisson?
Which scan tool are you using? Multi Scan.
Which vehicle are you using? Opel Vectra.
2.2 View the solenoids as the vehicle shifts up and down Record which solenoids are on in which gears?
with the shift lever in Drive or Overdrive?
First gear solenoids: off on
Second gear solenoids on off
third gear solennoids on off
furth gear solenoids off on
Veiw the Toque Converter Clutch as you safely drive the vehicle. Record when it is on or off?
Torque Converter Clutch On ?
Active when Accelerating.
Torque Converter Clutch Off?
Turns off when it is not Accelerating.
What effect does the brake padal have on the Torque Converter Clutch?
When the brake padal is applied the Torque Converter Clutch is released from the flywheel disengged.
Create Shift Chartfor your vehicle. Based on the operation of the shifting above create a shift chart that describes what solenoids are on in which gear?
