ELECTRIC POWER STEERING (EPS) ON-BOARD DIAGNOSIS

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On-Board Diagnostic (OBD) Test Description

• The OBD test inspects the integrity and function of the EPS and outputs the results when requested by the specific tests.

• On-board diagnostic test also:

― Provides a quick inspection of the EPS usually performed at the start of each diagnostic procedure.

― Provides verification after repairs to ensure that no other faults occurred during service.

• The OBD test is divided into 3 tests:

― Read/clear diagnostic results, PID monitor and record and active command modes.

Read/clear diagnostic results

• This function allows reading or clearing of DTCs in the EPS control module memory.

PID/Data monitor and record

• This function allows access of certain data values, input signals, calculated values, and system status information.

Active command modes

• This function allows control of devices through the M-MDS.

Reading DTCs Procedure

1. Connect the M-MDS to the DLC-2.

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2. After the vehicle is identified, select the following items from the initialization screen of the M-MDS.

• When using the IDS (laptop PC)

1. Select “Self Test”.

2. Select “Modules”.

3. Select “EPS”.

• When using the PDS (Pocket PC)

1. Select “Module Tests”.

2. Select “EPS”.

3. Select “Self Test”.

3. Verify the DTC according to the directions on the screen.

• If any DTCs are displayed, perform troubleshooting according to the corresponding DTC inspection.

4. After completion of repairs, clear all DTCs stored in the EPS. (See Clearing DTCs Procedures.)

Clearing DTCs Procedures

1. Connect the M-MDS to the DLC-2.

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2. After the vehicle is identified, select the following items from the initialization screen of the M-MDS.

• When using the IDS (laptop PC)

1. Select “Self Test”.

2. Select “Modules”.

3. Select “EPS”.

• When using the PDS (Pocket PC)

1. Select “Module Tests”.

2. Select “EPS”.

3. Select “Self Test”.

3. Verify the DTC according to the directions on the screen.

4. Press the clear button on the DTC screen to clear the DTC.

5. Turn the ignition switch to the LOCK position.

6. Turn the ignition switch to the ON position and wait for 5 s or more.

7. Perform DTC inspection. (See Reading DTCs Procedure.)

8. Verify that no DTCs are displayed.

PID/Data Monitor and Record Procedure

1. Connect the M-MDS to the DLC-2.

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2. After the vehicle is identified, select the following items from the initialization screen of the M-MDS.

• When using the IDS (laptop PC)

1. Select “DataLogger”.

2. Select “Modules”.

3. Select “EPS”.

• When using the PDS (Pocket PC)

1. Select “Module Tests”.

2. Select “EPS”.

3. Select “DataLogger”.

3. Select the applicable PID from the PID table.

4. Verify the PID data according to the directions on the screen.

Note

• The PID data screen function is used for monitoring the calculated value of input/output signals in the module.Therefore, if the monitored value of the output parts is not within the specification, it is necessary to inspect the monitored value of input parts corresponding to the applicable output part control. In addition, because the system does not display an output part malfunction as an abnormality in the monitored value, it is necessary to inspect the output parts individually.

Active Command Modes Procedure

1. Connect the M-MDS to the DLC-2.

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2. After the vehicle is identified, select the following items from the initialization screen of the M-MDS.

• When using the IDS (laptop PC)

1. Select “DataLogger”.

2. Select “Modules”.

3. Select “EPS”.

• When using the PDS (Pocket PC)

1. Select “Module Tests”.

2. Select “EPS”.

3. Select “DataLogger”.

3. Select the active command modes from the PID table.

4. Perform the active command modes, inspect the operations for each parts.

• If the operation of output parts cannot be verified after the active command mode inspection is performed, this could indicate the possibility of an open or short circuit, sticking, or operation malfunction in the output parts.

DTC Table

DTC

Diagnosis system component

Page

M-MDS

B1318

Battery power supply

(See DTC B1318.)

B1342

EPS control module

(See DTC B1342.)

B2141

EPS system (neutral position setting not performed)

(See DTC B2141.)

B2278

Torque sensor

(See DTC B2278.)

C1099

EPS motor

(See DTC C1099.)

U0073

CAN bus communication error

(See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (L.H.D.)].)

(See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)].)

U1900

CAN communication error

U2023

CAN communication error

DTC	Diagnosis system component	Page
B1318	Battery power supply	(See DTC B1318.)
B1342	EPS control module	(See DTC B1342.)
B2141	EPS system (neutral position setting not performed)	(See DTC B2141.)
B2278	Torque sensor	(See DTC B2278.)
C1099	EPS motor	(See DTC C1099.)
U0073	CAN bus communication error	(See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (L.H.D.)].) (See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)].)
U1900	CAN communication error
U2023	CAN communication error

PID/DATA Monitor Table

PID Name (Definition)

Unit/Condition

Condition/Specification

Action

EPS control module terminal

B+

(System battery voltage value)

V

•  IG switch ON: B+

Inspect battery. (See BATTERY INSPECTION [13B-MSP].)

Inspect power supply circuit (such as IG switch, fuse).

2P

CCNT

(Number of continuous codes)

—

•  DTCs are detected: 1—255

•  No DTCs are detected: 0

Perform inspection using appropriate DTC.

—

EPS_MTR

(EPS motor drive signal)

A

•  Steering wheel is not turned: Near 0 A

•  Steering wheel is turned right: 0—127 A

•  Steering wheel is turned left: 0— -128 A

Inspect EPS control module. (See EPS CONTROL MODULE INSPECTION.)

Inspect EPS motor circuit.

Inspect power supply circuit (such as IG switch, fuse).

4A, 4B

EPSLAMP

(EPS warning light output state)

On/Off

•  EPS warning light is illuminated: On

•  EPS warning light is not illuminated: Off

Inspect EPS control module. (See EPS CONTROL MODULE INSPECTION.)

Inspect instrument cluster.

—

RPM

(Engine speed signal)

RPM

•  Engine speed 1,000 rpm: 1000 RPM

Inspect PCM. (See PCM INSPECTION [13B-MSP].)

—

TRQ_S_CORR

(System neutral position setting)

Nm

•  Steering wheel is not turned: Near 0 Nm
(If system neutral position setting has not been performed, 31.75 Nm is output.)

Perform EPS system neutral position setting. (See EPS SYSTEM NEUTRAL POSITION SETTING.)

—

TRQ_SENS

(Torque sensor signal)

Nm

•  Steering wheel is not turned: Near 0 Nm

•  Steering wheel is turned right: 0—31.75 Nm

•  Steering wheel is turned left: 0— -32 Nm

Inspect torque sensor. (See TORQUE SENSOR INSPECTION.)

Inspect torque sensor circuit.

3A, 3B, 3C

VSS

(Vehicle speed signal)

KPH, MPH

•  Vehicle is stopped:
0 KPH/0 MPH

•  Vehicle speed 20 km/h {12 mph}: 20 KPH/12 MPH

Inspect PCM. (See PCM INSPECTION [13B-MSP].)

Inspect instrument cluster. (See INSTRUMENT CLUSTER INSPECTION.)

Inspect DSC HU/CM. (See DSC HU/CM INSPECTION.)

—

PID Name (Definition)	Unit/Condition	Condition/Specification	Action	EPS control module terminal
B+ (System battery voltage value)	V	• IG switch ON: B+	Inspect battery. (See BATTERY INSPECTION [13B-MSP].) Inspect power supply circuit (such as IG switch, fuse).	2P
CCNT (Number of continuous codes)	—	• DTCs are detected: 1—255 • No DTCs are detected: 0	Perform inspection using appropriate DTC.	—
EPS_MTR (EPS motor drive signal)	A	• Steering wheel is not turned: Near 0 A • Steering wheel is turned right: 0—127 A • Steering wheel is turned left: 0— -128 A	Inspect EPS control module. (See EPS CONTROL MODULE INSPECTION.) Inspect EPS motor circuit. Inspect power supply circuit (such as IG switch, fuse).	4A, 4B
EPSLAMP (EPS warning light output state)	On/Off	• EPS warning light is illuminated: On • EPS warning light is not illuminated: Off	Inspect EPS control module. (See EPS CONTROL MODULE INSPECTION.) Inspect instrument cluster.	—
RPM (Engine speed signal)	RPM	• Engine speed 1,000 rpm: 1000 RPM	Inspect PCM. (See PCM INSPECTION [13B-MSP].)	—
TRQ_S_CORR (System neutral position setting)	Nm	• Steering wheel is not turned: Near 0 Nm (If system neutral position setting has not been performed, 31.75 Nm is output.)	Perform EPS system neutral position setting. (See EPS SYSTEM NEUTRAL POSITION SETTING.)	—
TRQ_SENS (Torque sensor signal)	Nm	• Steering wheel is not turned: Near 0 Nm • Steering wheel is turned right: 0—31.75 Nm • Steering wheel is turned left: 0— -32 Nm	Inspect torque sensor. (See TORQUE SENSOR INSPECTION.) Inspect torque sensor circuit.	3A, 3B, 3C
VSS (Vehicle speed signal)	KPH, MPH	• Vehicle is stopped: 0 KPH/0 MPH • Vehicle speed 20 km/h {12 mph}: 20 KPH/12 MPH	Inspect PCM. (See PCM INSPECTION [13B-MSP].) Inspect instrument cluster. (See INSTRUMENT CLUSTER INSPECTION.) Inspect DSC HU/CM. (See DSC HU/CM INSPECTION.)	—

Active Command Mode Table

Command Name

Definition

Operation

Note

TRQ_S_CAL

EPS system neutral position setting

On/Off

Ignition switch at ON

DTC	Diagnosis system component	Page
M-MDS	Diagnosis system component	Page
B1318	Battery power supply	(See DTC B1318.)
B1342	EPS control module	(See DTC B1342.)
B2141	EPS system (neutral position setting not performed)	(See DTC B2141.)
B2278	Torque sensor	(See DTC B2278.)
C1099	EPS motor	(See DTC C1099.)
U0073	CAN bus communication error	(See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (L.H.D.)].) (See FOREWORD [MULTIPLEX COMMUNICATION SYSTEM (R.H.D.)].)
U1900	CAN communication error
U2023	CAN communication error