1.Operation principle of engine immobiliser set (transponder key ECU control type)
When the ignition key is pulled out of the ignition key cylinder, the key unlock warning switch is turned off. The transponder key ECU detects this signal and sets the engine immobiliser system and the security indicator light continues to flash.
When the key is turned from the ON to ACC or LOCK position, and 20 seconds elapse in this condition, the transponder key ECU detects it from the terminal IG, sets the engine immobiliser system and continues flashing the security indicator light.
2.Operation principle of engine immobiliser unset (transponder key ECU control type)
(1)Inserting the ignition key
When the ignition key is inserted into the ignition key cylinder, the key unlock warning switch turns on. The transponder key ECU detects this signal and this ECU supplies power via the terminal VC5 to the transponder key amplifier and transmits the operation signal via the TXCT terminal. As a result, current is allowed to flow into the transponder key coil and produces a magnetic field around the key cylinder.
(2)Engine immobiliser system unset
With the magnetic field produced around the ignition key cylinder, the ID code signal registered in the transponder chip built in the key is transmitted to the transponder coil. The transponder key amplifier transmits this signal to the terminal CODE of the transponder key ECU.
The transponder key ECU checks this received key side ID code with the registered ID code. If the ECU judges that these signals match, it transmits and receives signals by using the special communication line (terminal EFIO and terminal EFII) to instruct “engine start permission” to the engine ECU, causing the engine immobiliser system to unset.
(3)Turning security indicator light off
When the transponder key ECU unsets the engine immobiliser system, the security indicator light flash control is finished and the light is turned off.
If the transponder key ECU’s terminal +B circuit becomes open, turning the ignition switch ON causes the backup power to be supplied to the transponder key ECU and starts the ID code matching.

The transponder key ECU control type engine immobiliser system consists of the following components.
1.Ignition key (Transponder chip is built in)
The coil in the transponder chip built in the key reacts to the magnetic field produced by the transponder key coil. As a result, electricity is charged and an ID code is transmitted. Therefore, it is not necessary for the transponder chip to use a battery.
Ignition keys are classified into ignition key all-in-one type and separate type. The transponder chip of the separate type is built in the transmitter.
2.Transponder key coil
The transponder key coil produces a magnetic field around the ignition key cylinder and receives the ID code of the key.
3.Transponder key amplifier
According to the signal from the transponder key ECU, the transponder key amplifier allows the current to flow into the key coil and makes it produce a magnetic field.
The transponder key amplifier outputs the ID code of key received by the transponder key coil to the transponder key ECU.
4.Transponder key ECU
Transponder key ECU receives the ID code of key from the transponder key amplifier and checks it with the registered ID code. According to the result of the check, it determines whether the engine can be started and transmits the signal to the engine ECU.
This ECU controls the security indicator light to flash/go off.
5.Engine ECU
According to the engine start permission signal from the transponder key ECU, the engine ECU starts the engine.
6.Key unlock warning switch
This switch detects that the key is inserted into the ignition key cylinder and outputs the signal to the transponder key ECU.
7.Security indicator light

The engine immobiliser system is a theft deterrent system for vehicles. This system prohibits the engine from starting by igniting the engine and injecting fuel when any keys other than the ignition key with a ID code* previously registered in the vehicle is used.
While the engine immobiliser system is set, the security indicator light flashes to indicate that the system is set.
The engine immobiliser system consists of the transponder chip, transponder key coil, transponder key amplifier, transponder key ECU, engine ECU, etc.
There are two types of engine immobiliser systems, one that controls by a separate ECU (transponder key ECU), and another that controls by an ECU (engine ECU) that is integrated with the transponder key ECU.
*ID code (transponder key code)

Function
1.Engine immobiliser set/unset function
(1)Engine immobiliser set
The moment the ignition key is pulled out of the key cylinder or 20 seconds after the key is turned to ACC or LOCK position, the engine immobiliser is set and ignition of the engine and injection of fuel is disabled.
With the engine immobiliser set, even if the ignition switch that is removed from the ignition key cylinder is turned directly using a flat-head screwdriver or equivalent to START position in order to start the starter, the engine cannot be started. This is because the engine is not ignited and fuel is not injected.
(2)Engine immobiliser unset

2.Transponder key code registration function
The transponder key code registration function consists of an initial (automatic) registration, additional registration, and deletion.
The master key registered in the ECU is used to perform additional registration and deletion.
Refer to the Repair Manual (North America) or Service Bulletin (General country) for details.
(1)Initial registration of key code
This is a system to automatically register a new transponder key code (master key code and sub-key code) when the ECU is replaced.
After the ECU is replaced, turning the ignition switch ON makes the security indicator lamp blink. In this condition, inserting the master key and sub-key in the ignition key cylinder automatically registers the transponder key code in the ECU.
In the initial (automatic) registration mode, the transponder key code can be registered for up to three or four keys. The last registration (the third or fourth key) is performed at the sub-key registration mode.
After the initial registration, it may take some models approximately 30 minutes to match the communication ID between the transponder key ECU and the engine ECU.
(2)Registration of additional key code
This is a function to perform the additional registration of a new transponder key code (master key code and sub-key code) with the transponder key code registered in the ECU.
The figure shows an example of the additional registration method for the transponder key ECU control type. This registration method is performed by ignition switch operation and the open/close operation of the driver’s door.
Additional registration can also be performed using a hand-held tester.
For the engine ECU control type, registration and erasure are performed by operating the brake pedal and accelerator pedal.
The number of the registration of the transponder key code varies depending on the models.
(3)Erasure of key code
This is a function to erase all the transponder key codes except for the master key code that is used for the erasure.
(4)The difference between master key and sub-key
Two or three master keys and a sub-key are set in the ignition keys for the engine immobiliser system. Registration and erasure of the key can be performed only by the master key. Therefore, to register the sub-key, the master key is necessary. The setting of the master key and sub-key is also classified according to the registration methods.
(5)When all the master keys are lost
If all the registered master keys are lost, to register a new key, replacement of the transponder key ECU or Engine ECU and a set of keys is required.
In some countries, some models have a key code reset function.

The starter consists of the following components.
1.Magnetic switch
2.Armature
3.Yoke sub-assembly
4.Brush and brush holder
5.Reduction gear
6.Overrunning clutch
7.Pinion gear and helical spline

1.Magnetic switch
The magnetic switch operates as a main switch of the current flowing to the motor and controls the pinion gear by pushing and pulling it.
The pull-in coil is wound up with thicker wire than the hold-in coil, and its magnetomotive force of the pull-in coil is also greater than that of the hold-in coil.
2.Armature and ball bearing
The armature generates a motor’s revolving force, and the ball bearing supports the high speed revolution of the armature.
3.Yoke sub-assembly
The yoke sub-assembly produces the magnetic field required for the motor to operate. It also works as an outer case of the field coil, the pole core and a passage of the lines of magnetic force. The field coil is connected to the armature coil in series.
4.Brush and brush holder
The brushes are pressed against the armature commutator by the brush springs, allowing the current to flow from the coil to the armature in fixed direction. The brushes are made of copper-carbon, which has excellent conductivity and abrasion resistance characteristics. The brush springs repress the excessive revolution of the armature and stop the armature revolution just after the starter stops by pressing the brush.
Weakened brush springs or worn brushes may lead to insufficient electrical contact between the brushes and the segments of the commutator. The resulting excessive electrical resistance at the contact points will reduce the supply of current to the motor, impeding torque build-up.
5.Reduction gear
The reduction gear transmits the revolving force of the motor to the pinion gear and increases torque by slowing the motor speed as well. The reduction gear reduces the revolution of the motor at a reduction ratio of 1/3-1/4, and it has an overrunning clutch built-in.
6.Overrunning clutch
The overrunning clutch transmits the motor rotation to the engine via the pinion gear.
In order to prevent the starter breakage by its high-speed revolution arising from engine start, the overrunning clutch is a one-way type with rollers.
7.Pinion gear and helical spline
The pinion gear and the ring gear transmit the revolving force of the starter to the engine by securely engaging with each other. The pinion gear is chamfered for excellent engagement. The helical spline converts the revolving force of the motor to the driving force of the pinion and supports the engagement and the disengagement of the pinion gear as well.

Since the engine cannot be started by itself, external power is required to generate the first combustion to start it. To start the engine, the starter rotates the crankshaft via the ring gear.
The starter is required to generate extremely large torque from the limited power from the battery and should be compact and light as well. For this reason, a DC (direct current) series motor* is used for the starter.
To start the engine, the crankshaft has to rotate faster than the minimum cranking speed. The minimum cranking speed required to start the engine differs depending on the engine’s construction and operating conditions, but it is generally 40 to 60 rpm for a gasoline engine and 80 to 100 rpm for a diesel engine.
*DC (direct current) series motor
The DC (direct current) series motor consists of the field coil and the armature coil connected in series, and it is used to generate the maximum torque when the starter begins to turn.

Type of starter
(1)Reduction type
The reduction type starter uses a compact high-speed motor.
The reduction type starter increases torque by reducing the rotational speed of the armature with the reduction gear.
The plunger of the magnetic switch directly pushes the pinion gear located on the same axis and causes it to engage with the ring gear.
(2)Conventional type
The pinion gear is located on the same axis as the armature and rotates at the same speed.
The drive lever connected to the magnetic switch plunger pushes the pinion gear and causes it to engage with the ring gear.
(3)Planetary type
The planetary type starter uses a planetary gear to reduce the rotational speed of the armature.
The pinion gear engages with the ring gear via the drive lever, as with the conventional type.
(4)Planetary reduction-segment conductor motor (PS) type
The Planetary reduction-segment conductor motor (PS) type starter uses the permanent magnets in the field coil.
The engagement/disengagement mechanism works in the same way as the planetary type.

Poor braking effectiveness indicates not only the case where the brake does not operate at all even when the brake pedal is depressed, but also the case where the brake effectiveness is weak against the depressing force or there is no pedal feel. When troubleshooting poor braking effectiveness, it is vital to have a thorough compensation of the technical aspects in order to understand why the braking effectiveness worsens.

Poor braking effectiveness mainly occurs under the following conditions.
1. When there is a malfunction in the brake system
2. When the vacuum pressure in the brake booster is not maintained
3. When fade phenomenon or vapor lock occurs
4. When the vehicle gross weight is increased due to passengers or laden weight
5. When driving on a submerged road
6. When the friction coefficient changes between the tire and the road surface

Poor Braking Effectiveness

1. In the case when there is a malfunction in the brake system
Trouble in the brake system usually occurs in the rubber parts of the hydraulic system such as the brake hose, the piston cup, etc. Long -term use of the rubber parts in the system results in deterioration, which causes fluid leakage. Moreover, emergency braking may result in a deteriorated part bursting suddenly, causing the braking system to lose control. There are two brake hydraulic systems in the brake system concerning safety. However, when either of these systems have a malfunction, braking will be affected.
2. When the vacuum pressure in the brake booster is not maintained
If the engine stalls while driving, the vacuum pressure in the booster is not maintained. Pressure in the booster is not secured. In this case, the brake functions correctly only once. The brake pedal will feel heavy and the brake seems to be ineffective after the second trial.
Even when the booster does not operate, it does not mean that the brake effectiveness is not gained. If the driver fully depresses the brake pedal, braking is effective although the deceleration rate is less than normal.
3. In the case where fade phenomenon or vapor lock occurs
Fade phenomenon
The resin contained in the friction materials of the pad and shoe produce gas when the temperature of the pad and shoe increases. Poor braking effect results if the gas that acts as a lubricant reduces the friction coefficient. The fade phenomenon tends to occur especially during the initial period because the pad and shoe contains appropriate conditions for producing the gas.

Poor Braking Effectiveness
The thermal history can be checked by disassembling the brake unit responsible for the fade phenomenon.

Vapor lock
The driver doesn’t feel any reaction from the brake pedal and the braking effect is reduced when bubbles occur in the brake fluid. The bubbles are produced when the heat in the pad and shoe is transferred to the brake fluid and the fluid boils.

Conditions causing vapor lock
• After stopping a vehicle, the brake unit is not cooled down by
sufficient airflow.
• The brake fluid is not changed for a long time.
Be sure to remove the air from the fluid. Once the vapor lock occurs, bubbles remain in the piping although the brake pedal operating force returns to normal after the brake cools down.

4. In the case where the vehicle gross weight is increased due to passengers or laden weight
As the vehicle weight becomes heavier, stopping inertia becomes greater. The stopping distance will be longer even if the brake pedal is depressed with the same force.
5. In the case where driving on a submerged road
Temporary poor braking effect is caused by the low friction coefficient due to the lubricating action of the water when the friction material in the brake becomes wet. Repeated braking allows the water to evaporate and regain the braking effect with friction heat.
6. When the friction coefficient changes between the tire
and road surface
Tires tend to slip and the stopping distance becomes longer when running on a wet or snow covered road or using worn tires. If emergency braking is applied under such conditions, tires will lock and make the vehicle unstable resulting in a spin.

Braking and Pedal Operating Force Check
1. Maximum braking force check
Measure braking force using a brake tester
Criteria
There must be no difference when comparing with another vehicle of the same model.
2. Compare the breaking force and pedal operating force
Measure the breaking force and pedal operating force using a pedal effort meter and brake tester.
Criteria
There must be no difference when comparing with another vehicle of the same model.

The cause of vehicle pull is sometimes on the vehicle side and sometimes due to the road conditions or customer’s habitual usage. When performing troubleshooting for vehicle pull, it is important to understand the cause of it.

Judgement of vehicle pull
It is difficult to judge vehicle pull by using an electrical tester, etc. So, perform a road test and judge whether it is a malfunction or not.
• Compare with another vehicle of the same model
• Measure how much it moves within a certain distance
Measure how many meters the vehicle offsets in 100 meters.

Cause of vehicle pull
• Force generated on the tire
• Influence of alignment
• Influence of road surface

Force Generated on the Tire
The force generated on the tire may cause vehicle pull. The typical phenomenon is shown below.
• Ply steer
The transverse direction force is generated due to the ply direction of the tire belt. When the tires are rotated straight ahead, the force that tries to move the tires in the transverse direction along the ply is referred to as ply steer.
• Conicity
When applying a lateral force to the surface of a standing tire, portion contacting with the ground will alter shape evenly. However, unevenness of the tread, the force that returns it to the original shape is not equal. If rolling the tire in this condition, the tire rolls in the direction where the reaction force is smaller. In this condition, the force in the transverse direction is referred to as conicity. Inspection methods regarding whether the force generating on a tire affects vehicle pull or not.
• Change the left and right tires. Or remove the tire from the wheel and reverse.
Ply steer: The direction does not change at all.
Conicity: The direction changes.
Infl uence of Alignment
Vehicle pull occurs when there is an imbalance between the forces: moving to the right and to the left.
Alignment that has conformity with vehicle pull.
• Difference between right and left of cambers Moves to the positive (+) side
• Difference between right and left of casters Moves to the smaller side
• Difference between right and left of the king pin angles Moves to the negative side when braking

Influence of Road Surface
As for trails, each centre of contact on the ground between right and left are different, so the king pin offset dimension of the right and that of the left differ. Therefore, since the moment around the king pin axis differs between right and left, the steering wheel moves to the side where the moment is larger.

Influenced conditions
• Depth of the trails:
As the trail becomes deeper, the level becomes larger.
• Width of the tires:
As the tire width becomes wider, the level becomes larger.
• Tire tread rigidity:
As the tire tread rigidity becomes higher, the level becomes higher.
Some roads are slightly sloped for drainage. For this reason, the steering becomes unstable in only a specific place, or the direction differs when going somewhere and returning to the original place.

Mechanically Abnormal Sound and Noise
The engine consists of many parts, and each part operates by a sliding or rotational movement. The portion that slides or moves by rotational movement has clearance without exception and when this clearance becomes larger than the specification, an abnormal sound or noise can be heard.
The sound resulting from abrasion in the engine has the following characteristics
1. Occurrence condition
• When the engine is cold, the sound is loud.
• When the oil viscosity is insufficient, the sound is loud.
• When the hydraulic pressure is low, the sound is loud.
• When accelerating, the sound is loud.
• When the load is heavy, the sound is loud.
2. Sound types
• Sliding sound: the sound of things rubbing together.
• Hitting sound: the sound produced by hitting.
• Other sounds: Generally obscured and complicated sounds.
• Sound when idling
• Sound in the specified engine speed range
• Sound at various engine speed range
Abnormal Sound and Noise Caused by Abnormal Combustion
1. Knocking
During acceleration, a high-pitch hitting sound is produced.
The piston and the valve receive a bad influence and the engine may be damaged.
Main cause
• Poor fuel quality
Octane number of the fuel is lower than the required
• Ignition timing is advance
If the ignition timing is advanced, combustion is performed suddenly. As a result, knocking occurs.
• Spark plug failure
The overheated spark plug becomes a heat spot and causes pre-ignition. Suitable temperature for spark plug: approximately 450 to 950 degrees centigrade (self-cleaning temperature)
• Carbon accumulation in the combustion chamber
If carbon accumulates in the combustion chamber, the carbon prevents the heat from being dissipated and the engine overheats. The heated portion becomes a heat spot and causes pre-ignition.
• Air fuel mixture ratio is lean
During high speeds and with a heavy load, if the air fuel mixture ratio is lean, knocking will occur easily.
• Over load operation
When the engine load is excessive, knocking will occur easily. If the vehicle is continued to be driven while knocking occurs, the malfunction as shown below could occur.
• Overheating
• Metal damage due to engine overheating
• The amount of fuel consumption increases due to reduced heat efficiency
• Spark plug, piston and valve melt down.
• Cylinder head gasket breakage.
2. Run on (dieseling)
This is a phenomenon in which spontaneous combustion occurs. This phenomenon is caused when the fuel sucked in by the inertia of the crankshaft or fl ywheel, overheated spark plug that ignites the unburned gas and the carbon accumulated in the combustion chamber becomes a heat source even after the ignition switch is turned off. In an EFI engine, when the ignition switch is turned on, the fuel stops. Therefore, run on does not occur.
Main cause
• Inappropriate fuel
The fuel self-ignition temperature or octane number is low.
• High intake temperature
The compressed air fuel mixture temperature becomes higher than the self-ignition temperature.
• High-pressure compression (high-speed, high-load running)
Combustion temperature and the combustion chamber wall temperature are both high. When the pressure is high, the compressed air fuel mixture temperature also becomes high.
• Carbon accumulation inside the combustion chamber
When carbon accumulates inside the combustion chamber, the carbon prevents the heat from being dissipated and the engine overheats. The overheated portion becomes a heat spot.
• Spark plug failure
Spark plug is over-burned and becomes heat a spot.
• Idling speed is high
The amount of intake air when the throttle valve is fully closed is large.
• Engine overheating
Temperatures of combustion chamber parts become higher.
• Ignition timing retards
The maximum burning temperature lowers, but the combustion duration becomes longer and the exhaust temperature becomes higher. The temperature near the exhaust valve rises and becomes the heat source of the spontaneous combustion.

<2> Narrow down fuel system
• Fuel pressure inspection
When the symptom occurs, check whether the fuel pressure exists or not.
In the case where fuel pressure exists
• Injector and injection control and the relevant area
• Ignition system
In the case where fuel pressure does not exist
• Fuel pressure feed system including the fuel pump
• Fuel pump control system
• Air fuel ratio inspection
Using a hand-held tester, judge the A/F condition when the symptom occurs based on the O2 sensor voltage.
When it is not possible to narrow down the cause to the ignition and fuel systems, inspect for causes other than those relating to engine control.
• ECTs
• Mechanical cause in the engine
• The cause of A/F rich and lean that is not observed with the tester.
Narrow Down Using Tachometer
During a road test, narrow down whether the malfunction cause is in the ignition primary side or not by observing how much the indicator of the tachometer drops when the problem symptom recurs. In the tachometer or tune up tester that counts the number of counter electromotive generated in the ignition primary coil and converts it into the engine speed, if a malfunction occurs in the ignition primary system, the indicator of the tachometer distinctively drops.
Inspection methods
Inspect the movement of the indicator in the tachometer when hesitation occurs.
Criteria:
• When the indicator dramatically drops: A malfunction in the primary ignition system
• When the indicator gradually drops: A malfunction in an area other than the primary ignition system
This inspection cannot be performed in the system where the ECU counts the Ne signal, etc. and sends the engine speed to the tachometer.

Engine stall
There are many conditions under which engine stall occurs.
• When the engine is idling, the engine speed becomes unstable and the engine stalls.
• While the vehicle is running, when the accelerator pedal is released because there is a red traffic signal, the engine stalls.
• When accelerating or going over humps, the engine loses power and stalls. As for engine stall, reproducing the problem symptoms is difficult in most cases. In order to reproduce the symptoms during troubleshooting, it is necessary to ascertain from the customer the conditions under which engine stall occurs. After the engine stalls, difficulty in restarting or poor idling often occurs. This is also an important point when troubleshooting.
Hesitation
Hesitation is considered to be a light symptom of engine stall. But the symptom occurs only momentarily so a speedy, yet accurate inspection should be performed while the hesitation occurs. As for the cause of the hesitation, there are roughly two types, mechanical type in the engine, for example, the valve stick, and electrical type, for example, the operating EFI system. Further, another cause, such as an ECT shifting problem, can also be considered, so it is necessary to understand the malfunction from a wide point of view.

1. Conformity with the result of the DTC output
Even if the DTC indicates abnormality, the malfunction that the DTC indicates is different from the malfunction that the customer points out. Therefore, inspect the relationship between the DTC and the problem symptom.
When there is conformity between the DTC and symptom
• If the symptom continuously occurs, the malfunction is judged to be in the area where the DTC is indicated.
• If the symptom does not occur, it is necessary to inspect while the malfunction is occurred by using the reproducing method.
When there is a hesitation malfunction, using diagnosis test mode, ascertain the malfunction area in which the malfunction momentarily occurs, and efficiently narrow down the malfunction cause.

2. Narrowing down using the data of ECU
By analyzing the data of ECU when the malfunction occurs, judge whether the sensor range/performance problem or the malfunction related to the actuator can be narrowed down or not.

3. Symptom occurrence condition confirmation
As for engine stall or hesitation, when there is difficulty in restarting or poor idling accordingly, or when the problem symptom occurs by using the reproduction method, etc. the occurrence conditions vary. Here, performing troubleshooting that matches in the symptom occurrence condition efficiently narrows down the malfunction cause.

(1) Difficulty in restarting after engine stalls
After the symptom occurs, proceed with the inspection following troubleshooting for difficulty in engine restarting.
(2) Restarts but idling trouble occurs after engine stalls
When the engine stalls as a result of poor idling, proceed with the inspection by following troubleshooting for poor idling.
(3) Symptoms occurs by reproduction method
When the malfunction occurs by using a reproduction method, the malfunction cause can be judged to be the area in which applied the reproduction method. Perform the troubleshooting narrowing down the malfunction at the area.
(4) Engine stall without idling trouble and difficulty in restarting the engine
The symptom occurs, however, when neither difficulty in restarting nor poor idling is accompanied by it, the symptom recurs only momentarily. Therefore, to observe the symptom is rather difficult. But when the symptom occurs, if the following items are inspected, the malfunction cause can be narrowed down to the fuel system or ignition system.

<1> Narrow down ignition system
It is difficult to clearly judge that the malfunction cause is in the ignition system. So narrow down the fuel system and after confirming that the system has no malfunction, inspect the parts and the connectors in the ignition system using reproduction method.