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
Which solenoids are "on" when this vehicle automatically shifts into third gear?
none
Which solenoids are "on" when this vehicle automatically shifts into fourth gear?
1-2
Shift solenoids malfunction: Describe what would happen if none of the solenoids came "on". What gear would it be in? How fast could the vehicle go? Could it have the power to climb a hill?
The vehicle only runs in third gear. So the vehicle could go around 60km/h. It could climb a small hill but the transmission go bad when climbing steep hill.
On car exercises
Scan tool: Hanatech
Vehicle: Mitsubish, Lancer
Record which solenoids are on in which gears:
First gear solenoids: 2nd and OD
Second gear solenoids: L/R and OD
Third gear solenoids: L/R and 2nd
Fourth gear solenoids: L/R U/D
View the Torque Converter Clutch as you safely drive the vehicle. Record when it is on or off:
Torque Converter Clutch On: At the speed of 100KM, it is fully on.
Torque Converter Clutch Off: At the speed of 50KM, it is fully off.
1. Using the wiring diagram identify the plugs/pins and wire colours for the communication lines between the nodes.
The drivers door(A15) and drivers side door(A2) are communicated by using a Brown colour wire.
The drivers side door(B1) and the passenger side door(B9) are communicated by using a Pink colour wire.
2. Using the wiring diagram identify the plugs/pins and wire colours for the Earths and voltage supply lines between the nodes.
Drivers door
Drivers side door
Passenger side door
Earths
(colours)
A12, A19
Black
B11, A14
Black
B22, A8
Black
Voltage supply
(colours)
A1
Pink
A12
Pink
A24
Pink
3. Create a fault in the unit and describe in detail how this fault is affecting the normal operation of this system
The drivers rear window does not go down.
4. Using the wiring diagram analyse the fault and describe in detail what may be causing this fault.
Relay of the right rear window could be faulty
Multiplex control unit could be faulty
Communication line between drivers door and drivers side door could be faulty
5. After reading the manual put the system in to test mode 1. Note the codes (if any) and possible faults that the system gives you.
Steps to put the system in to test mode 1 -
1. Turn on the S/W marked Multiplex(more than seven seconds)
2. Beep once (mode1)
3. If the system continues to beep, there is a DTC code stored
9. Put the system in to diagnostic mode 2, conduct the input tests and note the results.
Steps to put the system in to test mode 2 -
1. From mode 1 the muliplex switch off by seven seconds then turn the switch on.
2. Beep third time (modd2)
Using the dual trace feature on the oscilloscope capture the full pattern of the H-CAN and L-CAN, identify which wire is the H-CAN and which is for the L-CAN.
H-CAN: blue wire
L-CAN: yellow wire
Antilock Braking Systems help prevent the wheels from locking during sudden braking, especially on slippery surfaces. This helps the driver maintain control.
An antilock braking system is only an "add-on" to the existing base brake system. ABS only comes into play when traction conditions are marginal or during sudden panic stops when the tires lose traction and begin to slip excessively. The rest of the time ASB has no effect on normal driving, handling, or braking.
There are two situations in which an antilock brake system will not provide the shortest stopping distances.
The first involves straight stops made on smooth, dry pavement by an expert driver. Under these conditions, a skilled driver can hold the tires consistently closer to the ideal slip rate than the ABS can.
The other situation in which antilock brakes will not provide the shortest stops is when braking on loose gravel or dirt, or in deep snow. Under these conditions, a locked wheel will stop the vehicle faster because loose debris builds up and forms a wedge in front of the tire that helps stop the vehicle.
Off-car Exercises
Below are some possible causes for damaging an ECU.
Spiked by careless welding, i.e. MIG welding without disconnecting the battery
Enclosure seal damaged and with obvious sign of water ingress
Obvious signs of mechanical damage to the enclosure
Fautls are much more likely to be with connections or sensors
Often the ECU will be misdiagnosed as faulty, usually because the technician is inexperienced in faultfinding, so it is important to check the wires, sensors and connectors visually at first.
ABS wiring system
Wiring Diagram Practice
Identify the wheel speed sensors and list their wire colours for each sensor.
Front right: Black(B) and White(W)
Front left: Red(R) and Green(G)
Rear left: Pink (P) and Blue(L)
Rear right: Browns (BR) and Yellow(Y)
In the ABS wheel sensor what is the reason for the braded wire?
To prevent from interference from other cables
Identify and list all the fuses that are used by the ASB circuit
FL MAIN
50A ABS
15A ECU-IG
15A STOP
20A DOME
10A GAUGE
Identify the earths for the ABS control unit and ABS motor their wire colours what pin number.
Earths for the ABS control unit: 10B(W-B, White/Black) and 7B(W-B, White/Black)
Earths for the ABS motor: 1A(W-B, White/Black)
On the wiring diagram for the ABS actuator, identify which solenoids control which wheel cylinder. Then note the wire colours and pin number.
(SFRA: Solenoid Front Right Actuator, SRLR: Solenoid Rear Left Releasing)
Front Right Wheel: Pin number: 2B Wire colour: Red/White(R-W)
Front Left Wheel: Pin number: 3B Wire colour: Blue/Red(L-R)
Rear Left Wheel: Pin number: 1B Wire colour: Brown/White(BR-W)
Rear Right Wheel: Pin number: 4B Wire colour: Green/Black(G-B)
What are the correct conditions of the inlet and outlet solenoids valves under normal braking?
Inlet valve Open and Outlet valve Closed
What are the correct conditions of the inlet and outlet solenoids valves when the ABS is operating to reduce wheel brake pressure?
Inlet valve Closed and Outlet valve Open
What are the correct conditions of the inlet and outlet solenoids valves when the ABS is operating to hold brake pressure?
Inlet valve Closed and Outlet valve Closed
What are the correct conditions of the inlet and outlet solenoids valaves when the ABS is operating to increase wheel brake pressure?
Inlet valve Open and Outlet valve Closed
In the four cases above state when the ABS motor will be working?
When the ABS is operating to increase or decrease wheel brake pressure, the ABS motor will be working.
ABS Demonstrators
Record which ECU wires go to which wheel speed sensors:
Left front ECU Pin#4 and Pin#5
Left rear ECU Pin#7 and Pin#9
Right front ECU Pin#11 and Pin#21
Right rear ECU Pin#24 and Pin#26
Record a waveform for each wheel speed sensor.
Left front wheel speed sensor
Volt/division: 5V
Time/division: 500uS
Left rear wheel speed sensor
Volt/division: 5V
Time/division: 500uS
Right front wheel speed sensor
Volt/division: 5V
Time/division: 500uS
Volt/division: 20V
Time/division: 500uS
Right rear wheel speed sensor
Volt/division: 5V
Time/division: 500uS
Are all the waveforms exactly the same? No
Discuss what are the differences and what can causes these differences between the waveforms.
As shown above patterns, the pattern of the right front wheel speed sensor has high voltage amplitude compared to other patterns. There is more big gap between the right front wheel speed sensor and a toothed ring.
With the wheel speed sensors spinning, measure AC volts with a multi-meter and record here:
Left front: 5.77V
Left rear: 3.97V
Right front: 15.80V
Right rear: 5.00V
Can a multi-meter be as accurate in finding problems with the wheel speed sensors as an oscilloscope? No
ABS Relays
Record the name of the relay or switch that powers up the ABS ECU: K39
Record the name of the relay or switch that powers up the ABS pump: K100
Record the name of the relay or switch that sends power to the ABS HCU solenoids: K38
What is the ECU pin number for the wire that brings in the power to the ABS ECU?
ECU pin#29, Brown/Yellow
What is the ECU pin number or other number, for the wire that controls the relay for the ABS ECU?
ECU pin# 1, Black/Red
What is the pin number for the wire that brings in the power to the ABS Pump?
ECU pin#14, Red/Yellow
What is the pin number or other number, for the wire that controls the relay for the ABS Pump?
ECU pin#28, Grey/Green
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.
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.
Channel A -
Volt/division: 5V
Time/division: 1S
Channel B -
Volt/division: 10V
Time/division: 1S
Point A: When the relay switch is closed, 12V applied
Point B: When the relay switch is opened, the voltage drops to 0V.
Point C: There is a voltage spike because of magnetic field collaping
Point E: There are some oscillations when the ABS pump stops.
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 Self Test.
The ECU performs a self-test after the ignition is switched on. If there is a failure during the self-test, an ABS warning light will be on and it will disconnect the ABS system. If the self-test is normal, an ABS warning light will go off after about 5 seconds. The main purpose of the self-test is to monitor the input(e.g wheel speed sensor) and the output(e.g operation of valves).
Catch an oscilloscope pattern when an ABS solenoid has actuated. What is the pin and name of the solenoid?
Ignition: On, Engine: Off - Check Engine Light lights up
Ignition: On, Engine: On - Check Engine Light should go off, if Check Engine Light remains ON, fault has been detected.
Procedures to extract the codes:
1. Turn the Ignition switch ON
2. Open the diagnostic plug
3. Connect terminals "TE1" and "E1" by using jumper wires
4. Read the fault code
I found the fault code which is "31". By refering to the Codes list, it is described as "Vacuum sensor circuit".
Firstly, I did a visual inspection under the bonnet around MAP sensor. Then I found the MAP sensor has been disconnected. Pluged back in the connector.
To clear the faults codes, EFI fuse has been removed. After one minute, put the EFI fuse back.
When the engine started, Check Engine Light went off. It means there is no fault code.
Fuel Pressure and flow
Make: Toyota
Mode: 4A-FE
Fuel pressure specifications
1. Measure the fuel pressure with the key on, engine off. - 290 kPa
2. Measure the fuel pressure with the engine idling. - 340 kPa
3. With the engine idling, use the special tool to clamp the fuel return line. (NB. this can only be done for a short period) - 500 kPAa
4. With the engine idling, disconnect and plug the vacuum line going to the fuel pressure regulator. - 320 kPa
If the vacuum hose is removed from the fuel pressure regulator when the engine is running, the fuel pressure should increase. If it does not increase, then the fuel pump is not capable of supplying adequate pressure or the fuel pressure is defective. If gasoline is visible in the vacuum hose, the regulator is leaking and should be replaced. Also, when the hose is reattached to the regulator, the fuel pressure should drop.
5. Turn off the engine, and watch the fuel pressure for five minutes. - 300 kPa
Describe the symptons a vehicle would give with each case.
Low fuel pressure - Hard cold starts, Garage stalls, Poor cold performance, Hesitation just as the accelerator pedal is depressed
Low fuel flow - stalls from time to time while driving
High fuel pressure - Run rich, high CO, poor fuel economy
Faulty fuel pressure regulator - Stalling, sometimes run rich so high CO
