ELECTRIC POWER STEERING (EPS) ON-BOARD DIAGNOSIS


id060200813500


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 2 tests:
―  Read/clear diagnostic results, PID monitor and record.

Read/clear diagnostic results

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


PID/Data monitor and record

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


Reading DTCs Procedure


CMDTC self test

1.  Connect the M-MDS (IDS) to the DLC-2.

2.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “Self Test”.
(2)  Select “All CMDTCs”.

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

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

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


ODDTC self test

1.  Connect the M-MDS (IDS) to the DLC-2.

2.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “Self Test”.
(2)  Select “Modules”.
(3)  Select “EPS”.

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

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

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


Snapshot Data Access Procedure

1.  Connect the M-MDS (IDS) to the DLC-2.

2.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “Self Test”.
(2)  Select “Modules”.
(3)  Select “EPS”.

3.  Then, select the “Retrieve CMDTCs” and perform procedures according to directions on the IDS screen.

4.  Retrieve the freeze frame PID data according to the directions on the IDS screen.

Note
•  Snapshot data appears at the top of the help screen when the displayed DTC is selected.
•  Snapshot data stores the currently detected DTC data.


Clearing DTCs Procedure


CMDTC clearing procedure

1.  Switch the ignition OFF and wait for 1 min.

2.  Connect the M-MDS (IDS) to the DLC-2.

3.  Switch the ignition ON (engine off).

4.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “Self Test”.
(2)  Select “All CMDTCs”.

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

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

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

8.  Verify that no DTCs are displayed.


ODDTC clearing procedure

1.  Switch the ignition OFF and wait for 1 min.

2.  Connect the M-MDS (IDS) to the DLC-2.

3.  Switch the ignition ON (engine off).

4.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “Self Test”.
(2)  Select “Modules”.
(3)  Select “EPS”.

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

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

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 (IDS) to the DLC-2.

2.  After the vehicle is identified, select the following items from the initialization screen of the IDS.

(1)  Select “DataLogger”.
(2)  Select “Modules”.
(3)  Select “EPS”.

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.
•  When detecting DTCs, PIDs related to a malfunctioning system may not display even if the module is normal. Therefore, if a PID is not displayed, it is necessary to verify the DTC, perform malfunction diagnosis of the DTC that was detected, and do repairs.

DTC Table

×: Applicable
—: Not applicable

DTC

Power steering malfunction indicator light illumination status

Diagnosis system component

Fail-safe

Drive cycle

Self test type*1

Memory function

Page

M-MDS

C200B:02
Illuminated
Torque sensor
×
C, D
×
C200B:16
Illuminated
Torque sensor
×
C, D
×
C200B:1C
Illuminated
Torque sensor
×
C, D
×
C200B:62
Illuminated
Torque sensor
×
C, D
×
C200B:64
Illuminated
Torque sensor
×
C, D
×
C200B:85
Illuminated
Torque sensor
×
C, D
×
C200C:1C
Illuminated
Torque sensor
×
C, D
×
C200D:1C
Flashes/Illuminated*2
Resolver sensor
×
C, D
×
C200D:64
Illuminated
Resolver sensor
×
C, D
×
U0001:88
Illuminated
CAN system communication error
×
C, D
×
U0100:00
Illuminated
Communication error to PCM
×
C, D
×
U0121:00
Communication error to DSC CM
×
C, D
×
U0155:00
Communication error to instrument cluster
×
C, D
×
U0214:00
Communication error to start stop unit
×
C, D
×
U0338:00
Signal error from start stop unit
×
C, D
×
U0401:00
Illuminated
Signal (vehicle speed) error from PCM
×
C, D
×
Signal (engine speed) error from PCM
×
C, D
×
U0415:00
Signal error from DSC CM
×
C, D
×
U0423:00
—*3
Signal (engine switch status) error from instrument cluster
×
C, D
×
U0515:00
Signal error from start stop unit
×
C, D
×
U2011:19
Illuminated
EPS motor
×
C, D
×
U2011:1C
Illuminated
EPS motor
×
C, D
×
U2011:62
Illuminated
EPS motor
×
C, D
×
U2011:72
Illuminated
EPS motor
×
C, D
×
U2011:92
Illuminated
EPS motor
×
C, D
×
U2300:54
EPS configuration
×
C, D
×
U2300:55
Illuminated
EPS configuration
×
C, D
×
U2300:56
EPS configuration
×
C, D
×
U3000:16
Illuminated
EPS CM
×
C, D
×
U3000:1C
Illuminated
EPS CM
×
C, D
×
U3000:28
Illuminated
EPS CM
×
C, D
×
U3000:41
Illuminated
EPS CM
×
C, D
×
U3000:46
EPS CM
×
C, D
×
U3000:47
Illuminated
EPS CM
×
C, D
×
U3000:49
Illuminated
EPS CM
×
C, D
×
U3000:4B
EPS CM
×
C, D
×
U3000:61
Illuminated
EPS CM
×
C, D
×
U3000:73
Illuminated
EPS CM
×
C, D
×
U3000:96
Illuminated
EPS CM
×
C, D
×
U3003:16
Illuminated
Battery power supply
×
C, D
×
U3003:17
Illuminated
Battery power supply
×
C, D
×

*1  :C: CMDTC self test, D: ODDTC self test
*2  :If the EPS CM detects an internal circuit malfunction in the resolver sensor, it flashes the power steering malfunction indicator light. At this time, if EPS system internal temperature increases, the assist force gradually weakens. Then if assist force decreases below the specified value, the power steering malfunction indicator light switches from flashing to illumination.
*3  :If the EPS CM detects the signal that a engine speed is below the specified value, it illuminates the power steering malfunction indicator light.

Fail-safe Function Table

DTC

Fail-safe control status

M-MDS

C200B:02
Control disabled
C200B:16
Control disabled
C200B:1C
Control disabled
C200B:62
Control disabled
C200B:64
Inhibits normal control, switches to backup control, and controls electric power steering so that steering assist can be maintained
C200B:85
Control disabled
C200C:1C
Control disabled
C200D:1C
Control is maintained in the backup control and the power steering warning buzzer is sounded
―  If EPS system internal temperature increases above the specified value, the EPS CM disables assistance and stops the power steering warning buzzer is sounded
C200D:64
Control disabled
U0001:88
Control enabled
U0100:00
Control is maintained by gradually changing the controlled vehicle speed and setting it to 100 km/h {62.1 mph}
U0121:00
Control enabled
U0155:00
Control enabled
U0214:00
Control enabled
U0338:00
Control enabled
U0401:00
•  Vehicle speed signal malfunction
―  Control is maintained by gradually changing the controlled vehicle speed and setting it to 100 km/h {62.1 mph}
•  Engine speed signal malfunction
―  Control enabled
U0415:00
Control enabled
U0423:00
Control enabled
―  If the EPS CM detects the signal that a engine speed is below the specified value, it disables assistance
U0515:00
Control enabled
U2011:19
Control disabled
U2011:1C
Control disabled
U2011:62
Control disabled
U2011:72
•  An open circuit malfunction is detected in the one phase of the three-phase stator in the EPS motor
―  Control is maintained in the backup control
•  Other malfunction detected in EPS motor internal circuit
―  Control disabled
U2011:92
Control disabled
U2300:54
Control enabled
U2300:55
Control enabled
U2300:56
Control enabled
U3000:16
Control disabled
U3000:1C
Control disabled
U3000:28
Control disabled
U3000:41
Control disabled
U3000:46
Control is maintained in fail mode
U3000:47
Control disabled
U3000:49
Control disabled
U3000:4B
Control is maintained in fail mode
U3000:61
Control disabled
U3000:73
Control disabled
U3000:96
Control disabled
U3003:16
Control is maintained by gradually decreasing the motor control current
However, control is inhibited if the power supply voltage is the specified value of less.
U3003:17
Control disabled


PID/DATA Monitor Table

Note
•  If the PID/data monitor value “STR_ANG” is inspected, perform the following procedure before inspecting.
1.  Switch the ignition to OFF, and maintain this condition for approx. 3 s.
2.  Set the vehicle wheels in the straight-ahead position.
3.  Switch the ignition ON (engine off or on).

—: Not applicable

PID name (definition)

Unit/Operation

Operation Status (Reference)

Inspection item(s)

EPS control module terminal

M-MDS display

CEN_TRQ_S
Nm
•  Torque sensor neutral position: Near 0 Nm
•  Steering column replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
ECU_IN_TMP
°C, °F
•  Displays temperature of board in EPS control module: -40°C—+215°C {-40°F—419°F}
•  EPS CM replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
ENG_RPM
RPM
•  Engine stopped: 0 RPM
•  Engine rotating at 3,000 RPM: 3,000 RPM
MT_CURRENT
A
•  When not steered: Near 0 A
•  Steered: Changes to positive or negative
•  EPS CM replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
OH_CR_C
Yes/No
•  Overheat protection control (complete) is operating: Yes
•  Overheat protection control (complete) is not operating: No
OH_CR_M
Yes/No
•  Overheat protection control (middle) is operating: Yes
•  Overheat protection control (middle) is not operating: No
OH_HIST_C
Yes/No
•  Before overheat protection control (complete) has operated: Yes
•  Before overheat protection control (complete) has not operated: No
OH_HIST_M
Yes/No
•  Before overheat protection control (middle) has operated: Yes
•  Before overheat protection control (middle) has not operated: No
OH_IG_CNT_C
•  The number of times the ignition is switched ON during the period from when overheat protection control (complete) is finished to the time the next overheat protection control (complete) is started
―  Displays a maximum number of 255 times in which the ignition is switched ON until the first overheat protection control (complete) is started.
―  During overheat protection control (complete), the number of times the ignition is switched ON is not counted, and 0 is displayed.
OH_IG_CNT_M
•  The number of times the ignition is switched ON during the period from when overheat protection control (middle) is finished to the time the next overheat protection control (middle) is started
―  Displays a maximum number of 255 times in which the ignition is switched ON until the first overheat protection control (middle) is started.
―  During overheat protection control (middle), the number of times the ignition is switched ON is not counted, and 0 is displayed.
STR_AB_EST
°
•  Steering wheel in neutral position (not turned):
•  Steered left: Changes to 0°—Positive
•  Steered right: Changes to 0°—Negative
Note
•  The signal displayed in this item is a estimated absolute steering angle signal output.
Perform the DTC inspection for the PCM, DSC HU/CM, and EPS CM.
If a DTC is displayed after performing the DTC inspection for the PCM, DSC HU/CM, and EPS CM, repair the malfunctioning part according to the applicable DTC troubleshooting.
After performing the DTC inspection, perform the following procedures:
•  Switch the ignition off and maintain condition for approx. 3 s.
•  Set the vehicle wheels straight-ahead.
•  Switch the ignition ON (engine off or on).
If an abnormal value is indicated after verifying the value of the STR_ANG again, replace the EPS CM.
STR_ANG
°
•  Steering wheel position when ignition is switched ON (engine off or on):
•  Steered left: Changes to 0°—Positive
•  Steered right: Changes to 0°—Negative
Note
•  The signal displayed in this item is a steering angle (relative angle) signal.
STR_ROT_SPD
°/s
•  Not steered: Near 0 °/s
•  Steered: Changes according to steering speed
•  EPS CM replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
STR_TRQ_S_M
Nm
•  Not steered: Near 0 Nm
•  Steered left: Changes to 0 Nm—Positive
•  Steered right: Changes to 0 Nm—Negative
•  EPS CM replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
STR_TRQ_S_S
Nm
•  Not steered: Near 0 Nm
•  Steered left: Changes to 0 Nm—Positive
•  Steered right: Changes to 0 Nm—Negative
•  EPS CM replacement (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
VPWR
V
•  Engine stopped: Approx. 12 V
•  Idling: Approx. 14 V
•  Power supply circuit inspection (ignition switch, fuses)
1B
VSPD
KPH, MPH
•  Vehicle stopped: 0 KPH, 0 MPH
•  Vehicle speed 20 km/h {12 mph}: 20 KPH, 12 MPH


Snapshot Data Table

Note
•  Refer to PID monitor table for confirm the EPS system operation status while the EPS does not store the DTC. (See PID/DATA Monitor Table.)
•  Snapshot data items are not displayed, according to detected DTC.

—: Not applicable

Snapshot data item

Unit

Data contents

Data read/use method

Corresponding data monitor items

AAT
°C, °F
Ambient air temperature
APP_STATUS
Accelerator Pedal Off/
Under 20%/
Over 20%/
FAIL
Accelerator pedal position
CEN_TRQ_S
Nm
Center value of torque sensor
CEN_TRQ_S
CFG_STATUS
Config Complete/
Not Configured/
Config Error
Instrument cluster configuration status
ECT_STATUS
Under 0 degrees C/
0 - Under 80 degrees C/
Over 80 degrees C/
FAIL
Engine coolant temperature status
ECU_IN_TMP
°C, °F
ECU internal temperature
ECU_IN_TMP
ENG_RPM
RPM
Engine speed
ENG_RPM
IC_VPWR
V
Instrument cluster power supply
•  The EPS CM constantly receives the power supply voltage value of the instrument cluster sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the power supply voltage of the instrument cluster when the DTC was detected, and it is displayed in the M-MDS.
VPWR*2
IG-ON_TIMER
hh:mm:ss*1
Elapsed time since ignition was switched ON
Note
•  The instrument cluster records the elapsed time since the ignition was switched ON.
•  The EPS CM constantly receives the elapsed time since the ignition was switched ON sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the elapsed time since the ignition was switched ON when the DTC was detected, and it is displayed in the M-MDS.
MT_CURRENT
A
Motor current
MT_CURRENT
OH_CR_C
No/Yes
Current overheat protection control (complete)
OH_CR_C
OH_CR_M
No/Yes
Current overheat protection control (middle)
OH_CR_M
OH_HIST_C
No/Yes
History of overheat protection control (complete)
OH_HIST_C
OH_HIST_M
No/Yes
History of overheat protection control (middle)
OH_HIST_M
OH_IG_CNT_C
The number of times the ignition is switched ON during the period from when overheat protection control (complete) is finished to the time the next overheat protection control (complete) is started
•  Displays a maximum number of 255 times in which the ignition is switched ON until the first overheat protection control (complete) is started.
•  During overheat protection control (complete), the number of times the ignition is switched ON is not counted, and 0 is displayed.
OH_IG_CNT_C
OH_IG_CNT_M
The number of times the ignition is switched ON during the period from when overheat protection control (middle) is finished to the time the next overheat protection control (middle) is started
•  Displays a maximum number of 255 times in which the ignition is switched ON until the first overheat protection control (middle) is started.
•  During overheat protection control (middle), the number of times the ignition is switched ON is not counted, and 0 is displayed.
OH_IG_CNT_M
PWR_MODE_KEY
Key Out/Key Recently Out (Position 0)/Accessory (Position 1)/Post Ignition (Position 2)/Ignition On (Position 2)/Running (Position 2)/Running - Starting
•  Key Out: Ignition switched off
•  Key Recently Out (Position 0): Elapsed time within 3 s since ignition was switched off
•  Accessory (Position 1): Ignition is switched to ACC
•  Post Ignition (Position 2): Elapsed time within 3 s since ignition was switched ON
•  Ignition On (Position 2): Ignition switched ON (engine off)
•  Running (Position 2): Ignition switched ON (engine on)
•  Running - Starting: Cranking condition
•  The EPS CM constantly receives the ignition switch status sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the ignition switch status when the DTC was detected, and it is displayed in the M-MDS.
RPM_STATUS
Engine Stop/
Under 1500rpm/
Over 1500rpm/
FAIL
Engine RPM status
•  The EPS CM constantly receives the ignition switch status sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the ignition switch status when the DTC was detected, and it is displayed in the M-MDS.
TACHOMTR*2
SHIFT_STATUS
P/N
D/
R/
FAIL
Shift position status
•  The EPS CM constantly receives the selector lever position sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the selector lever position when the DTC was detected, and it is displayed in the M-MDS.
Not applicable
STR_AB_EST
°
Steering wheel estimated absolute angle
STR_AB_EST
STR_ANG
°
Steering wheel angle
STR_ANG
STR_ROT_SPD
°/s
Steering wheel rotation speed
STR_ROT_SPD
STR_TRQ_S_M
Nm
Steering shaft torque (Main)
STR_TRQ_S_M
STR_TRQ_S_S
Nm
Steering shaft torque (Sub)
STR_TRQ_S_S
TOTAL_DIST
km, ft, mi
Accumulated total traveled distance from completion of vehicle until EPS CM detects DTC (Odometer value in instrument cluster)
The distance traveled when the EPS CM detected a DTC can be calculated by performing the following procedure.
1.  Verify the odometer value in the instrument cluster.
2.  Verify the snap shot data item TOTAL_DIST.
3.  Subtract 2 from 1.
TOTAL_TIME
hh:mm:ss*1
Accumulated total elapsed time since vehicle completion until EPS CM detects a DTC
Note
•  When the ROOM removed, and the ignition is switched off, the time is not included in the elapsed time.
The elapsed time when the EPS CM detected a DTC can be calculated by performing the following procedure.
1.  Verify the PID item TOTAL_TIME of the instrument cluster.
2.  Verify the snap shot data item TOTAL_TIME.
3.  Subtract 2 from 1.
TOTAL_TIME*2
VPWR
V
Power supply
VPWR
VSPD
KPH, MPH
Vehicle speed
VSPD
VSPD_STATUS
Stop/
0 - 10km/h/
Over 10km/h/
FAIL
Vehicle speed status
•  The EPS CM constantly receives the vehicle speed sent via CAN signal from the instrument cluster.
•  If a DTC is detected, the EPS CM records the vehicle speed when the DTC was detected, and it is displayed in the M-MDS.
SPEEDOMTR*2

*1  :The seconds may be indicated after the decimal point.
*2  :Instrument cluster PID (See PID/DATA MONITOR TABLE [INSTRUMENT CLUSTER].)