Toyota Camry 2007-2009 Service Manual - Power_Steering

	POWER STEERING – POWER STEERING SYSTEM	PS–1
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POWER STEERING SYSTEM

PRECAUTION

NOTICE:

When disconnecting the cable from the negative (-) battery terminal, initialize the systems after the cable is reconnected (See page IN-43).

1.HANDLING PRECAUTIONS FOR STEERING SYSTEM

(a)Care must be taken when replacing parts. Incorrect replacement may affect the performance of the steering system and result in driving hazards.

2.HANDLING PRECAUTIONS FOR SRS AIRBAG SYSTEM

(a)The vehicle is equipped with SRS (Supplemental Restraint System), such as airbags. If service operation is not carried out properly, in a step by step fashion, sudden deployment of the airbags may result in serious injury. Before servicing (including removal or installation of parts, inspection or replacement), be sure to read the precautionary notice for the supplemental restraint system (See page RS-1).

3.PRECAUTIONS FOR REMOVAL, INSTALLATION AND REPLACEMENT OF ELECTRONIC MOTOR POWER STEERING COMPONENTS

(a)Be sure to turn the front wheels straight ahead when removing and installing the power steering link assembly.

(b)If disconnecting the steering intermediate shaft subassembly and the power steering link assembly, be sure to put matchmarks before starting the operation.

(c)After replacing the power steering link assembly or power steering ECU assembly, clear the rotation angle sensor calibration value, initialize the rotation angle sensor, and calibrate torque sensor zero point (See page PS-13).

PS

PS–2	POWER STEERING – POWER STEERING SYSTEM

PROBLEM SYMPTOMS TABLE

HINT:

Use the table below to help determine the cause of the problem. The numbers indicate likely causes of the problem in descending order. Check each part in order. If necessary, repair or replace faulty parts.

POWER STEERING SYSTEM

		Symptom		Suspected Area	See page
			1.	Front tires (Improperly inflated, unevenly worn)	TW-3
			2.	Front wheel alignment (Incorrect)	SP-4
			3.	Front suspension (Lower ball joint)	SP-24
			4.	Steering column assembly	SR-35
			5.	Torque sensor (Built into steering link assembly)	-
		Steering is heavy.
			6. Power steering motor		-
			7.	Speed sensor	-
			8.	Skid control ECU	-
			9.	Battery and power source system	-
			10. Power steering ECU power source voltage and relay		-
			11. Power steering ECU		PS-68
			1. Calibration of turning angle sensor output and torque sensor		PS-13
			zero point is not completed
			2.	Front tires (Improperly inflated, unevenly worn)	TW-3
			3.	Front wheel alignment (Incorrect)	SP-4
		Steering effort differs between right and left or is	4.	Front suspension (Lower ball joint)	SP-24
		uneven.	5. Power steering link assembly		PS-58
			6.	Torque sensor (Built into steering link assembly)	-
			7.	Steering column assembly	SR-35
			8.	Power steering motor	-
			9.	Power steering ECU	PS-68
			1.	Front suspension (Lower ball joint)	SP-24
			2.	Speed sensor	-
			3.	Skid control ECU	-
		While driving, steering effort does not change in
			4.	Combination meter	-
		accordance with vehicle speed or the steering wheel
			5.	Engine speed detection circuit	-
		does not return properly.
			6.	Torque sensor (Built into steering link assembly)	-
			7.	Power steering motor	-
			8.	Power steering ECU	PS-68
		A knocking (or cranking) sound occurs when turning	1.	Front suspension (Lower ball joint)	SP-24
		the steering wheel back and forth while power steering	2. Steering intermediate shaft		-
		is in operation.
			3.	Power steering link assembly	PS-58
		Noise occurs when turning the steering wheel during	1. Power steering link assembly		PS-58
		low speed driving.	2. Steering column assembly		SR-35
		A high-pitched sound (squeaking) occurs when turning	1. Power steering motor		-
		the steering wheel slowly with the vehicle stopped.
		The steering wheel vibrates and noise occurs when	1. Power steering link assembly		PS-58
PS
		turning the steering wheel from lock to lock.	2. Steering column assembly		SR-35

POWER STEERING – POWER STEERING SYSTEM	PS–3

C132536

ON-VEHICLE INSPECTION

1.CHECK STEERING EFFORT (TORQUE) NOTICE:

Some service operations affect the SRS airbags. Be sure to read the precautionary notice for the SRS airbags before servicing (See page RS-1).

(a)Stop the vehicle on a level, paved surface and align the wheels straight ahead.

(b)Disconnect the cable from the negative (-) battery terminal.

CAUTION:

Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to prevent airbag and seat belt pretensioner activation.

(c)Remove the steering pad (See page RS-344).

(d)Connect the cable to the negative (-) battery terminal.

(e)Using a torque wrench, check if the steering wheel set nut is properly tightened.

Torque: 50 N*m (510 kgf*cm, 37 ft.*lbf)

(f)Turn the power switch on (READY) so that the power steering is available.

(g)Turn the steering wheel 90 degrees to the right and check steering effort (torque) while turning. Check in

the opposite direction using the same manner.

Steering effort (Reference):

6.0 N*m (60 kgf*cm, 53 in.*lbf) or less

Inspect the power steering system if the value is not within the specified range (See page PS-1).

(h)Align the front wheels straight ahead.

(i)Disconnect the cable from the negative (-) battery terminal.

(j)Install the steering pad (See page RS-346).

(k)Connect the cable to the negative (-) battery terminal.

(l)Clear the DTCs (See page RS-41).

(m)Perform initialization.

NOTICE:

Some systems need initialization after reconnecting the cable to the negative battery terminal (See page IN-43).

(n)Inspect the airbag warning light (See Page RS-33).

PS

PS–4

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

ELECTRONIC POWER STEERING SYSTEM

PRECAUTION

1. NOTICE FOR INITIALIZATION

(a) When disconnecting the negative (-) battery terminal, initialize the following systems after the terminal is reconnected.

System Name	See procedure
SFI System	(See page IN-43)

2. HANDLING PRECAUTIONS

(a) When handling the electronic parts:

(1) Avoid any impact to electronic parts such as ECUs and relays. Replace these parts with new ones if dropped or subjected to a severe blow.

(2) Do not expose any electronic parts to high temperature or humidity.

(3) Do not touch the connector terminals in order to prevent deformation or malfunctions due to static electricity.

(4) If the power steering ECU assembly has been replaced with a new one, initialize the rotation angle sensor value and calibrate the torque sensor zero point (See page PS-13).

(b) When handling the power steering link assembly:

(1) Avoid any impact to the power steering link assembly, especially to the motor or torque sensor. Replace these parts with new ones if dropped or subjected to a severe blow.

(2) Do not pull on the wire harness when moving the power steering link assembly.

(3) If the power steering link assembly has been replaced with a new one, clear the rotation angle sensor calibration value, initialize the rotation angle sensor value, and calibrate the torque sensor zero point (See page PS-13).

(c) When disconnecting and reconnecting the connectors:

(1) Turn the power switch on (IG), center the steering wheel, and turn the power switch off again before disconnecting the connectors related to the electronic power steering system.

(2) Ensure that the power switch is off before reconnecting the connectors related to the electronic power steering system. After reconnection, center the steering wheel and turn the power switch on (IG).

NOTICE:

Do not turn the power switch on (IG) when the steering wheel is not centered.

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–5

F045104E02

Bypass Wire

C106492E01

(3)If the above operations are not carried out properly, the steering center point (zero point) will deviate, which may lead to a difference in steering effort between right and left. If there is a difference in steering effort between right and left, perform steering zero point calibration (See page PS-13).

3.PRECAUTIONS FOR CAN COMMUNICATION

(a)CAN communication is used to receive information from the skid control ECU, power steering ECU, hybrid vehicle control ECU, and steering angle sensor and to transmit warnings to the combination meter. It is also used for communication between terminals Tc and Ts of the DLC3. If there are any problems in the CAN communication lines, DTCs indicating communication line malfunctions are output.

(b)Perform troubleshooting for communication line problems if CAN communication DTCs are output. Be sure to start troubleshooting on the electronic power steering system only when data communication is normal.

(c)Temporary fixing or repair with bypass wiring, etc. is impossible because the length and path of each CAN communication line is specified.

4.BUS LINE REPAIR

(a)After repairing the bus line with solder, wrap the repaired part with electrical tape.

NOTICE:

• The CANL bus line and CANH bus line must be installed together all the times.

When installing, make sure to twist them. CAN bus lines are likely to be influenced by electrical noise if they are not twisted.

• The difference in length between the CANL bus line and CANH bus line should be 100 mm (3.937 in.) or less.

•Leave approximately 80 mm (3.150 in.) loose in the twisted wires around the connector.

(b)Do not use bypass wiring between the connectors.

NOTICE:

The ability of the twisted bus lines to resist interference will be lost if bypass wiring is used.

PS

PS–6	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PARTS LOCATION

	HYBRID VEHICLE CONTROL ECU
	POWER STEERING LINK
	- TORQUE SENSOR
	- POWER STEERING MOTOR
	- ROTATION ANGLE SENSOR
	POWER STEERING ECU
	COMBINATION METER
	- PS WARNING LIGHT
	SKID CONTROL ECU
	DLC3
PS	MAIN BODY ECU (INSTRUMENT PANEL J/B)
	B150822E01

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–7

SYSTEM DIAGRAM

Motor Rotation	EPS Motor
Angle Sensor	Power Steering ECU Assembly
	- Motor Relay
	- Power Source Relay
	- Motor Current Sensor
Torque Sensor	- Temperature Sensor
	CAN
	Skid Control ECU
	Steering Angle Sensor
	Hybrid Vehicle Control ECU
	Combination Meter
	Main Body ECU (Instrument Panel J/B)
	PS
	B139367E01

	Transmitting ECU	Receiving ECU	Signals	Communication method
	(transmitter)
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	T/M variation information signal	CAN

PS–8	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

	Transmitting ECU	Receiving ECU	Signals	Communication method
	(transmitter)
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	Ready signal	CAN
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	Ambient temperature signal	CAN
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	Intake air temperature signal	CAN
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	Engine variation information	CAN
			signal
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	Vehicle destination information	CAN
			signal
	Hybrid Vehicle Control ECU	Power Steering ECU Assembly	TC terminal condition	CAN
	Skid Control ECU	Power Steering ECU Assembly	Output command value (to EPS)	CAN
			signal
	Skid Control ECU	Power Steering ECU Assembly	Additional torque target signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	Vehicle speed (SP1) status signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	Target steering angle signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	Target steering angle and	CAN
			additional torque valid signal
	Skid Control ECU	Power Steering ECU Assembly	Vehicle speed (SP1) signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	Test mode signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	VSC controlling signal	CAN
	Skid Control ECU	Power Steering ECU Assembly	ABS controlling signal	CAN
	Steering Angle Sensor	Power Steering ECU Assembly	Data continuity (valid/invalid)	CAN
			signal
	Steering Angle Sensor	Power Steering ECU Assembly	+B open circuit signal	CAN
	Steering Angle Sensor	Power Steering ECU Assembly	Sensor malfunction signal	CAN
	Steering Angle Sensor	Power Steering ECU Assembly	Steering angle signal	CAN
	Steering Angle Sensor	Power Steering ECU Assembly	Zero point memory (in sensor)	CAN
			valid/invalid signal
	Steering Angle Sensor	Power Steering ECU Assembly	Zero point (stored in steering	CAN
			angle sensor) signal
	Main Body ECU	Power Steering ECU Assembly	Vehicle model signal	CAN
	(Instrument Panel J/B)
	Power Steering ECU Assembly	Skid Control ECU	EPS pinion angle invalid signal	CAN
	Power Steering ECU Assembly	Skid Control ECU	EPS assisting current invalid	CAN
			signal
	Power Steering ECU Assembly	Skid Control ECU	EPS torque sensor value invalid	CAN
			signal
	Power Steering ECU Assembly	Hybrid Vehicle Control ECU	EPS idle up request signal	CAN
	Power Steering ECU Assembly	Skid Control ECU	EPS torque sensor value signal	CAN
	Power Steering ECU Assembly	Skid Control ECU	EPS pinion angle signal	CAN
	Power Steering ECU Assembly	Skid Control ECU	EPS assisting current signal	CAN
	Power Steering ECU Assembly	Combination Meter	EPS light ON request signal	CAN
	Power Steering ECU Assembly	Combination Meter	EPS diagnostic information signal	CAN

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–9

SYSTEM DESCRIPTION

1.	DESCRIPTION
	(a) The EPS system generates assist torque to assist
		steering effort through the operation of the motor
		installed on the power steering link assembly.
		The direction and amount of power assistance are
		determined by signals from the torque sensor, and
		controlled in accordance with vehicle speed. As a
		result, steering effort is controlled to be light during
		low speed driving and moderately high during high
		speed driving.
2.	FUNCTIONS OF COMPONENTS
Components		Function
		Calculates degree of assistance needed based on steering torque and
		vehicle speed. Drives the motor based on motor electric angle
Power Steering ECU Assembly		obtained from the motor rotation angle sensor.
		Boosts battery voltage to generate motor drive voltage.
		Restricts power assistance to protect the system if the motor and ECU
		overheat.
Torque Sensor		Detects steering effort generated when the steering wheel is turned.
Power Steering Motor		Located coaxially with the rack shaft. Its rotation is converted to the
		rectilinear motion of the steering rack via the ball screw nut and ball.
Hybrid Vehicle Control ECU		Transmits ready signal to the power steering ECU.

PS

PS–10	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

3.OPERATION EXPLANATION

	Torque Sensor Portion:
	Input Shaft		Torsion Bar
			Torque Sensor
	To Power Steering ECU
	Assembly
	Output Shaft
	Power Steering Motor Portion:		To Power Steering ECU
			Assembly
	From Power
	Steering ECU
	Assembly		Motor Rotation
			Angle Sensor
	Ball Screw
	Nut
	Ball
	Steering Rack	Power Steering Motor
			C106460E02

(a) The torque sensors is mounted on the input shaft to the main shaft and on the output shaft to the pinion shaft. The input and output shafts are joined by a

PS torsion bar.

(b) If the steering wheel is turned, the torsion bar twists, resulting in a difference in the rotation angle detected by the torque sensor. The power steering ECU assembly calculates torque based on this difference.

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–11

(c)The power steering ECU assembly calculates proper assisting torque, according to vehicle speed, based on the torque obtained in the previous step. Then the ECU controls the motor drive circuit in order to allow it to generate assisting torque.

(d)A ball screw nut is attached to the motor shaft. It converts the rotational motion of the motor into the rectilinear motion of the steering rack via the ball.

(e)The assisting force generated in the above process will reduce the steering effort required by the driver.

PS

PS–12	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

HOW TO PROCEED WITH TROUBLESHOOTING

Perform troubleshooting according to the following flowchart. HINT:

• For further details, see the page given.

• *: Use the intelligent tester.

1 VEHICLE BROUGHT TO WORKSHOP

NEXT

2CUSTOMER PROBLEM ANALYSIS

NEXT

3CHECK DTC AND FREEZE FRAME DATA*

(a) Record the DTCs and freeze frame data.

NEXT

4CLEAR DTC AND FREEZE FRAME DATA*

NEXT

5PROBLEM SYMPTOM CONFIRMATION

SYMPTOM DOES NOT OCCUR (GO TO STEP 6)

SYMPTOM OCCURS (GO TO STEP 7)

6SYMPTOM SIMULATION

NEXT

7CHECK DTC*

PS

(a)Recheck for DTCs. HINT:

•Refer to the diagnostic trouble code chart if any DTCs are output.

•If any CAN communication system DTCs are output, perform troubleshooting on the CAN communication system first (See page CA-7).

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–13

•If communication to the power steering ECU assembly is not established through the intelligent tester, inspect terminals SIL of the DLC3 and power steering ECU assembly, and inspect the IG circuit of the power steering ECU assembly.

NORMAL SYSTEM CODE IS OUTPUT: GO TO

STEP 8

TROUBLE CODE IS OUTPUT: GO TO STEP 9

8PROBLEM SYMPTOMS TABLE

NEXT

9DTC CHART

NEXT

10CIRCUIT INSPECTION*

NEXT

11IDENTIFICATION OF PROBLEM

NEXT

12REPAIR OR REPLACE

NEXT

13 CONFIRMATION TEST

NEXT

END

PS

PS–14	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

CALIBRATION

DLC3

Intelligent Tester

C131977E01

1.ROTATION ANGLE SENSOR VALUE INITIALIZATION AND TORQUE SENSOR ZERO POINT CALIBRATION NOTICE:

Clear the rotation angle sensor calibration value, initialize the rotation angle sensor value, and calibrate the torque sensor zero point if any of the following has occurred:

•The power steering ECU assembly has been replaced.

•The power steering link assembly has been replaced.

•Steering effort differs between left and right.

(a)Inspection before calibration

(1)Connect the intelligent tester (with CAN VIM) to the DLC3.

(2)Turn the power switch on (IG).

(3)Turn the intelligent tester on.

(4)Select "IG SUPPLY" from the data list.

(5)Check the IG power supply voltage on the tester screen.

	Tester Display	Measurement Item/Range	Inspection Condition	Reference Value
	IG SUPPLY	ECU power source voltage/	Power switch on (IG)	10 to 14 V
		Min.: 0 V, Max.: 25.5 V

Standard voltage: 10 to 14 V

NOTICE:

If the IG power supply voltage is 10 V or less, calibration cannot be performed. In this case, charge or replace the battery, and then perform calibration.

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–15

			(b) Rotation angle sensor calibration value clear,
			rotation angle sensor value initialization, and torque
			sensor zero point calibration.
			NOTICE:
			• If DTC C1516 (Torque Sensor Zero Point
			Adjustment Incomplete) is stored, the torque
			sensor zero point cannot be calibrated. Clear
			the DTC before starting calibration.
			• If DTC C1526 (Rotation Angle Sensor
			Initialization Incomplete) is stored, the
			rotation angle sensor value cannot be
			initialized. Clear the DTC before starting
DLC3			initialization.
	Intelligent Tester		(1) Connect the intelligent tester (with CAN VIM) to
			the DLC3.
		C131977E01
			(2) Turn the power switch on (IG).
			(3) Turn the intelligent tester on.
			(4) Select "TRQ SENSOR ADJ".
			(5) Follow the procedures on the tester display to
			clear the rotation angle sensor calibration value,
			initialize the rotation angle sensor value, and
			calibrate the torque sensor zero point.
			NOTICE:
			• When initializing the rotation angle sensor
			value, observe the following to stabilize
			sensor voltage:
			After turning the power switch on (IG),
			wait for at least 2.5 seconds before
			turning the steering wheel. Do not turn the
			steering wheel quickly.
			• The steering wheel will vibrate during
			torque sensor zero point calibration. Do
			not touch the steering wheel while it is
			vibrating or for 2 seconds after it stops.

PS

PS–16	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

PROBLEM SYMPTOMS TABLE

ELECTRONIC POWER STEERING SYSTEM

	Symptom		Suspected Area	See page
		1.	Front tires (Improperly inflated, unevenly worn)	TW-3
		2.	Front wheel alignment (Incorrect)	SP-4
		3.	Front suspension	SP-24
		4.	Power steering link assembly	PS-61
	Steering is heavy.	5.	Steering column assembly	SR-35
		6.	Battery and power source system	-
		7.	Power source voltage of power steering ECU assembly	PS-50
		8.	Power steering ECU assembly	PS-68
		9.	Vehicle condition (The steering wheel is turned from left to	-
		right repeatedly with the vehicles stopped or a heavy load is
		continuously applied to the vehicle)
		1.	Power steering ECU assembly (Steering center point is not	PS-13
		recorded correctly)
		2.	Front tires (Improperly inflated, unevenly worn)	TW-3
	Steering effort differs between right and left, or is	3.	Front wheel alignment (Incorrect)	SP-4
	uneven.	4. Front suspension		SP-24
		5.	Power steering link assembly	PS-61
		6.	Steering column assembly	SR-35
		7.	Power steering ECU assembly	PS-68
		1.	Speed sensor	BC-273
	While driving, steering effort does not change in
		2.	Skid control ECU	BC-289
	accordance with vehicle speed, or the steering wheel
		3.	Power steering link assembly	PS-61
	does not return to its centered position easily.
		4.	Power steering ECU assembly	PS-68
	Friction sounds occur when turning the steering wheel	1. Power steering link assembly		PS-61
	during low speed driving.	2. Power steering ECU assembly		PS-68
	High-pitched sounds (squeaking) occur when turning	Power steering link assembly		PS-61
	the steering wheel slowly with the vehicle stopped.
	The steering wheel vibrates and noise occurs when	1. Power steering link assembly		PS-61
	turning the steering wheel with the vehicle stopped.	2. Steering column assembly		PS-68
	PS warning light remains on.	PS warning light remains on		PS-50
	PS warning light does not come on.	PS warning light does not come on		PS-54

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–17

TERMINALS OF ECU

1.TERMINALS OF ECU

A66	A68	A67
		C116647E02

HINT:

The power steering ECU assembly uses waterproof connectors. Therefore, voltage or waveforms cannot be checked with the connectors connected to the vehicle.

Terminal No. (Symbols)	Wiring Color	Terminal Description
A66-2 (CANH)	B	High-level CAN bus line
A66-3 (CANL)	W	Low-level CAN bus line
A66-4 (PIG)	W	Power source
A66-5 (PGND)	B	Power ground
A66-9 (IG)	O	IG power source
A67-1 (RZG)	W	Rotation angle sensor power source circuit ground
A67-2 (SRZG)	BR	Rotation angle sensor shield ground
A67-3 (RZV)	G	Rotation angle sensor power source
A67-4 (TRQV)	P	Torque sensor power source
A67-6 (TQG1)	L	Torque sensor power source circuit ground
A67-7 (RZSN)	B	SIN phase input signal (Rotation angle sensor)
A67-8 (RZCS)	R	COS phase input signal (Rotation angle sensor)
A67-9 (INSN)	B	SIN phase input signal (Torque sensor input shaft side)
A67-10 (INCS)	R	COS phase input signal (Torque sensor input shaft side)
A67-11 (OUSN)	W	SIN phase input signal (Torque sensor output shaft side)
A67-12 (OUCS)	G	COS phase input signal (Torque sensor output shaft side)
A67-13 (TQG2)	Y	Torque sensor detection circuit ground
A68-1 (V)	R	V phase motor output
A68-2 (U)	B	U phase motor output
A68-3 (W)	W	W phase motor output

2.INSPECT WIRE HARNESS SIDE CONNECTOR

A66	A68	A67
		PS
		C116648E02

PS–18	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

Terminal No. (Symbols)		Wiring Color	Terminal Description	Condition	Specified Condition
A66-4 (PIG) - A66-5 (PGND)		W - B	Power source	Always	10 to 14 V
A66-5 (PGND) - Body ground		B - Body ground	Power ground	Always	Below 1 Ω
A66-9 (IG) - A66-5 (PGND)		O - B	IG power source	Power switch on (IG)	10 to 14 V
A68-2 (U) - A68-3 (W)/A68-1	(V)	B - W/R	U phase motor output	Always	Below 1 Ω
A68-3 (W) - A68-2 (U)/A68-1	(V)	W - BR	W phase motor output	Always	Below 1 Ω
A68-1 (V) - A68-2 (U)/ A68-3 (W)		R - B/W	V phase motor output	Always	Below 1 Ω

CG	SG CANH	SIL
	CANL	BAT
		H100769E16

DIAGNOSIS SYSTEM

1.CHECK DLC3

(a)The vehicle's ECU uses ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.

Symbols (Terminal No.)	Terminal Description	Condition	Specified Condition
SIL (7) - SG (5)	Bus "+" line	During transmission	Pulse generation
CG (4) - Body ground	Chassis ground	Always	Below 1 Ω
SG (5) - Body ground	Signal ground	Always	Below 1 Ω
BAT (16) - Body ground	Battery positive	Always	10 to 14 V
CANH (6) - CANL (14)	CAN bus line	Power switch off*	54 to 69 Ω
CANH (6) - CG (4)	HIGH-level CAN bus line	Power switch off*	200 Ω or higher
CANL (14) - CG (4)	LOW-level CAN bus line	Power switch off*	200 Ω or higher
CANH (6) - BAT (16)	HIGH-level CAN bus line	Power switch off*	6 kΩ or higher
CANL (14) - BAT (16)	LOW-level CAN bus line	Power switch off*	6 kΩ or higher

NOTICE:

*: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches or the doors.

If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–19

DLC3

Intelligent Tester

C131977E01

B150816

(b)Connect the cable of the intelligent tester (with CAN VIM) to the DLC3, turn the power switch on (IG) and attempt to use the intelligent tester. If the screen displays a communication error message, a problem exists in the vehicle side or tester side. HINT:

•If communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.

•If communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself. Consult the Service Department listed in the tool's instruction manual.

2.P/S WARNING LIGHT

(a)Check that the PS warning light comes on when the power switch is turned on (IG) and goes off in approximately 3 seconds.

If the warning light does not come on or remains on, inspect the PS warning light circuit.

	Trouble Area	See Procedure
	PS warning light circuit (Remains on)	PS-50
	PS warning light circuit (Does not come	PS-54
	on)

DTC CHECK / CLEAR

1. CHECK FOR DTCs

(a) Connect the intelligent tester (with CAN VIM) to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the intelligent tester on.

(d) Read the DTCs by following the display on the intelligent tester.

HINT:

Refer to the intelligent tester operator's manual for further details.

DLC3

Intelligent Tester

C131977E01

PS

PS–20	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

2.	CLEAR DTCs
	(a) Connect the intelligent tester (with CAN VIM) to the
	DLC3.
	(b) Turn the power switch on (IG).
	(c) Turn the intelligent tester on.
	(d) Clear the DTCs by following the display on the
	intelligent tester.
	HINT:
	Refer to the intelligent tester operator's manual for
	further details.
DLC3
Intelligent Tester
C131977E01

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–21

FREEZE FRAME DATA

DLC3

Intelligent Tester

C131977E01

1.FREEZE FRAME DATA NOTICE:

•It is difficult to show the specified values (judgement values) clearly because freeze frame data values change significantly due to differences in measurement conditions, surroundings, or vehicle conditions. For this reason, there may be a problem even when the values are within specifications.

•Turn the power switch on (IG) and park the vehicle on level ground. Check the freeze frame data by using the intelligent tester.

(a)Connect the intelligent tester (with CAN VIM) to the DLC3.

(b)Turn the power switch on (IG) and check the freeze frame data by following the prompts on the intelligent tester's display screen.

Tester Display	Item Description/Range	Inspection Condition		Reference Value
	Vehicle speed from meter/	1. Vehicle is stopped	1.	0 km/h (0 mph)
SPD	Min.: 0 km/h (0 mph), Max.: 300	2. Vehicle is driven at a constant
			2.	No significant fluctuation
	km/h (186 mph)	speed
ENGINE REV	Engine revolution/	Engine is running at a constant	No significant fluctuation
	Min.: 0 rpm, Max.: 12.800 rpm	speed
MOTOR ACTUAL	Amount of current to motor/	Power steering is in operation	Value changes in proportion to
	Min.: -128 A, Max.: 127 A		steering effort
	Demanded amount of current to		Value changes in proportion to
COMMAND VALUE	motor/	Power steering is in operation
			steering effort
	Min.: -128 A, Max.: 127 A
	Steering angle speed/		Value changes in proportion to
STR ANGL VEL	Min.: -4.096 deg/sec, Max.: 4.064	Steering wheel is turned
			steering speed
	deg/sec
THERMISTOR TEMP	ECU substrate temperature/	Power switch on (IG)		-
	Min.: -50°C, Max.: 205°C
	Power source voltage to activate
PIG SUPPLY	motor/	Power steering is in operation	10 to 14 V
	Min.: 0 V, Max.: 25.5 V
						PS
IG SUPPLY	ECU power source voltage/	Power switch on (IG)	10 to 14 V
	Min.: 0 V, Max.: 25.5 V
	Steering angle sensor signal
STR SENS SIG	status/	-		-
	OK or NG
TRQ1	Torque sensor 1 rotation angle/	Steering wheel is turned	Value changes from 0 to 360°
	Min.: 0 deg, Max.: 360 deg		every 22.5° of steering angle

PS–22	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

	Tester Display	Item Description/Range	Inspection Condition	Reference Value
	TRQ2	Torque sensor 2 rotation angle/	Steering wheel is turned	Value changes from 0 to 360°
		Min.: 0 deg, Max.: 360 deg		every 22.5° of steering angle
		Zero point value of torque sensor	Steering wheel is not turned	Values differ depending on
	TRQ1 ZERO VAL	1/
			(without load)	vehicle
		Min.: 0 deg, Max.: 360 deg
		Zero point value of torque sensor	Steering wheel is not turned	Values differ depending on
	TRQ2 ZERO VAL	2/
			(without load)	vehicle
		Min.: 0 deg, Max.: 360 deg
	STEERING TORQU	Steering torque/	Steering wheel is turned	Value changes in proportion to
		Min.: -7.0 N*m, Max.: 7.0 N*m		steering effort
	MOTOR ROTATE	Motor rotation angle/	Steering wheel is turned	Value changes from 0 to 360°
		Min.: 0 deg, Max.: 360 deg		every 5° of steering angle
		Demanded amount of current to
	COMMAND VALUE 2	motor 2/	-	-
		Min.: -128 A, Max.: 127 A
	PIG2 VOLTAGE	Motor drive voltage/	Power steering is in operation	27 to 34 V
		Min.: 0 V, Max.: 64 V
	MOTOR VOLTAGE	Motor power source voltage/	Power steering is in operation	27 to 34 V
		Min.: 0 V, Max.: 64 V
	MTR TERMINAL (U)	Motor terminal voltage (U phase)/	Power steering is in operation	0 to 34 V
		Min.: 0 V, Max.: 64 V
	MTR TERMINAL (V)	Motor terminal voltage (V phase)/	Power steering is in operation	0 to 34 V
		Min.: 0 V, Max.: 64V
	MTR TERMINAL (W)	Motor terminal voltage (W phase)/	Power steering is in operation	0 to 34 V
		Min.: 0 V, Max.: 64 V
		Number of times IG switch is
	IG ON/OFF TIMES	turned on after DTC detection/	-	-
		Min.: 0 time, Max.: 255 times
		Continuous overheat prevention
	MTR OVERHEAT	control record/	-	-
		REC or UNREC
		PIG power source voltage drop
	MTR LOW POWER	record/	-	-
		REC or UNREC
		Record of power revolution signal
	ENG REV INTER	interruption/	-	-
		REC or UNREC
		Record of steering angle sensor
	STR ANGL INTER	signal interruption/	-	-
		REC or UNREC
		Record of vehicle speed signal
	SPD SIG INVALID	invalid/	-	-
		REC or UNREC
	BATTERY VOLTAGE	Battery voltage/	-	10 to 14 V
		Min.: 0 V, Max.: 25.5 V
	PS ASSIST SIG	Power steering assist signal/	Power switch on (IG)	-
		ON or OFF
		Number of detected DTCs when
	# CODES	freeze frame data is stored/	-	-
		Min.: 0, Max.: 255

PS

POWER STEERING – ELECTRONIC POWER STEERING SYSTEM	PS–23

FAIL-SAFE CHART

If a problem occurs in the electronic power steering system, the PS warning light will come on in the combination meter and steering power assistance will be stopped, fixed at a particular point, or decreased simultaneously to protect the system.

	DTC No.	Malfunction	Fail-safe
	C1511
	C1512	Torque Sensor Circuit Malfunction
	C1513
	C1521
	C1522	Motor Circuit Malfunction
			Power assistance stops.
	C1523
	C1524
	C1528	Motor Rotation Angle Sensor Malfunction
	C1531	ECU Malfunction
	C1532
	C1555	Motor Relay Welding Failure
			System overheat prevention control continues
	C1533	ECU Malfunction	without using the substrate temperature
			sensor.
			Torque sensor zero point and rotation angle
	C1534	ECU Malfunction	sensor calibration value are set to the default
			values.
	C1541	Vehicle Speed Signal Malfunction	Amount of power assistance is fixed for a
	U0129	Lost Communication With Skid Control ECU	speed of 100 km/h (62 mph).

HINT:

The amount of power assistance may be decreased to prevent the motor and ECUs from overheating if the steering wheel is continuously turned when the vehicle is either stopped or driven at a low speed, or if the steering wheel is kept at either full lock position for a long time. In that case, the amount of power assistance will return to normal if the steering wheel is not turned for approximately 10 minutes with the engine idling.

PS

PS–24	POWER STEERING – ELECTRONIC POWER STEERING SYSTEM

DLC3

Intelligent Tester

C131977E01

DATA LIST / ACTIVE TEST

1.DATA LIST

HINT:

By accessing the data list displayed on the intelligent tester, values of switches, sensors and other related parts can be checked without removing any parts.

Reading the data list is the first step in troubleshooting and is one method to shorten labor time.

(a)Connect the intelligent tester (with CAN VIM) to the DLC3.

(b)Turn the power switch on (IG).

(c)Operate the intelligent tester according to the steps on the display and select the data list.

		Tester Display	Measurement Item/Range	Normal Condition		Reference Value
			Vehicle speed from meter/	1. Vehicle is stopped	1.	0 km/h (0 mph)
		SPD	Min.: 0 km/h (0 mph), Max.: 300	2. Vehicle is driven at a constant
					2.	No significant fluctuation
			km/h (186 mph)	speed
		ENGINE REV	Engine revolution/	Engine is running at a constant	No significant fluctuation
			Min.: 0 rpm, Max.: 12.800 rpm	speed
		MOTOR ACTUAL	Amount of current to motor/	Power steering is in operation	Value changes in proportion to
			Min.: -128 A, Max.: 127 A		steering effort
			Demanded amount of current to		Value changes in proportion to
		COMMAND VALUE	motor/	Power steering is in operation
					steering effort
			Min.: -128 A, Max.: 127 A
			Steering angle speed/		Value changes in proportion to
		STR ANGL VEL	Min.: -4.096 deg/sec, Max.: 4.064	Steering wheel is turned
					steering speed
			deg/sec
		THERMISTOR TEMP	ECU substrate temperature/	Power switch on (IG)		-
			Min.: -50°C, Max.: 205°C
			Power source voltage to activate
		PIG SUPPLY	motor/	Power steering is in operation	10 to 14 V
			Min.: 0 V, Max.: 25.5 V
		IG SUPPLY	ECU power source voltage/	Power switch on (IG)	10 to 14 V
			Min.: 0 V, Max.: 25.5 V
			Steering angle sensor signal
		STR SENS SIG	status/	-		-
			OK or NG
			Torque sensor 1 rotation angle/		Value changes from 0 to 360°
PS		TRQ1		Steering wheel is turned
			Min.: 0 deg, Max.: 360 deg		every 22.5° of steering angle
		TRQ2	Torque sensor 2 rotation angle/	Steering wheel is turned	Value changes from 0 to 360°
			Min.: 0 deg, Max.: 360 deg		every 22.5° of steering angle
			Zero point value of torque sensor	Steering wheel is not turned	Values differ depending on
		TRQ1 ZERO VAL	1/
				(without load)	vehicle
			Min.: 0 deg, Max.: 360 deg