2001 TOYOTA PRIUS O2 sensor

F12669
ON
E
2
FRR
PREG
PFR
PMC
EREGERR
EFR
DI±400
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
2 Check each pressure sensor.
PREPARATION:
(a) Install the LSPV gauge to the front caliper bleeder plug
portion, and bleed LSPV gauge.
SST 09709±29018
(b) Remove the brake ECU with connectors still connected.
CHECK:
Turn the ignition switch ON and depress the brake pedal, then
check the relation between the fluid pressure and voltage of ter-
minals of each pressure sensor shown below with the connec-
tor still connected.
Pressure sensor nameSymbols
Master cylinder pressure sensorPMC ± E2
Regulator pressure sensorPREG ± EREG
Front pressure sensorPFR ± EFR
Rear pressure sensorPRR ± ERR
OK:
Front brake caliper fluid pressureVoltage
0 kPa (0 Kgf/cm2, 0 psi)0.37 ± 0.63 V
5,883 kPa (60 kgf/cm2, 853 psi)1.57 ± 1.83 V
11,768 kPa (120 kgf/cm2, 1,706 psi)2.77 ± 3.03 V
HINT:
It should be taken into account that the difference in voltage be-
tween terminals is caused by the slightly different pressure ap-
plied to each pressure sensor.
OK Go to step 4.
NG
3 Check for open and short circuit in harness and connector between each pres-
sure sensor and brake ECU (See page IN±41).
NG Repair or replace harness or connector.
OK
Replace brake actuator.

F12687
DLC3
2DTs 4
Ts
8
4 CG14ID1GR±G
B11
W±B
AJ11
J/C
A
ID
C Instrument Panel J/BBrake ECU
J16
J/C
J24
J/CB
W±B W±B
A2K 8 3
GR±G GR±G
B DI±454
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
Ts Terminal Circuit
CIRCUIT DESCRIPTION
The sensor check circuit detects abnormalities in the speed sensor signal which cannot be detected by the
DTC check.
Connecting terminals Ts and CG of the DLC3 starts the check.
WIRING DIAGRAM
DI29J±12

F12396
TOYOTA
Hand±held Tester
DLC3
F12848
Tc
CG
Ts
F12871
Malfunction Code (Example Code 72)
7
2
ON
OFF
0.5 sec. 0.5 sec.
0.5 sec.
1.5 sec.4 sec.
Repeat
0.5 sec. ON
OFF
0.25 sec.
0.25 sec. Normal Code
A Cycle
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±461
2001 PRIUS (RM778U)
(e) In case of using TOYOTA hand±held tester:
Clear the DTC.
(1) Hook up the TOYOTA hand±held tester to the
DLC3.
(2) Turn the ignition switch ON.
(3) Operate the TOYOTA hand±held tester to erase the
codes. (See TOYOTA hand±held tester operator's
manual.)
2. INPUT SIGNAL CHECK (TEST MODE)
(a) In case of not using TOYOTA hand±held tester:
Check the input signal.
(1) Turn the ignition switch OFF.
(2) Using SST, connect terminals Ts and CG of DLC3.
SST 09843±18040
(3) Check the warning light goes off with driving more
than 20 km/h (12 mph).
HINT:
If the warning light goes off during driving, the sensor can be
judged to normal.
(4) Stop the vehicle.
(5) Using SST, connect terminals Tc and CG of DLC3.
SST 09843±18040
(6) Read the number of blinks of the PS warning light.
HINT:

See the list of DTC shown on the next page.

Even a sensor is normal, it output codes 71 and 72 during
test mode.
(7) After doing check, disconnect the SST from the ter-
minals Ts and CG, Tc and CG of DLC3, and turn the
ignition switch OFF.
SST 09843±18040

F12396
TOYOTA
Hand±held Tester
DLC3
DI±462
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
(b) In case of using TOYOTA hand±held tester:
Check the input signal.
(1) Hook up the TOYOTA hand±held tester to the
DLC3.
(2) Check the warning light goes off with driving more
than 20 km/h (12 mph).
(3) Read the DTC by following the prompts on the tes-
ter screen.
HINT:

Please refer to the TOYOTA hand±held tester operator's
manual for further details.

See the list of DTC shown on the bottom of this page.

Even a sensor is normal, it output codes 71 and 72 during
test mode.
DTC of input signal check function:
Code No.
(See page)DiagnosisTrouble Area
C1515/15
(DI±468)Calibration of torque sensor zero point Not Performed±
C1516/16
(DI±469)Calibration of torque sensor zero point Not completed±
C1571/71
C1572/72
(DI±474)
Speed sensor malfunction (Test mode)

Right rear or left rear speed sensor

Sensor installation

Right rear or left rear speed sensor rotor

Right rear or left rear speed sensor circuit

Brake ECU

EMPS ECU
3. CALIBRATION OF TORQUE SENSOR ZERO POINT
HINT:
Perform this operation in the following cases.

When removing and installing ºsteering wheelº, ºtilt steer-
ing columnºand ºelectric power steering gearº.

When replacing EMPS ECU.
(a) Place front wheels and steering wheel facing straight
ahead.
(b) In case of using TOYOTA hand±held tester:
Perform the torque sensor zero point initialization.
HINT:
If the EMPS ECU is replaced, however, this operation is not
necessary.
(1) Stop the vehicle.

F12396
TOYOTA
Hand±held Tester
DLC3
F12827
Tc
CG
Ts
F12864
Tc
CG
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±463
2001 PRIUS (RM778U)
(2) Hook up the TOYOTA hand±held tester to the
DLC3.
(3) Select the ºTRQ SENS ADJUSTº mode on the TOY-
OTA hand±held tester.
(4) Select the ºZERO POINT INITIALIZEº.
(5) Following the screen instructions, perform the
torque sensor zero point initialization.
HINT:
Please refer to the TOYOTA hand±held tester operator's manu-
al for further details.
(c) In case of not using TOYOTA hand±held tester:
Perform the torque sensor zero point initialization.
HINT:
If the EMPS ECU is replaced, however, this operation is not
necessary.
(1) Stop the vehicle.
(2) Using SST, connect terminals Ts and CG of DLC3.
SST 09843±18040
(3) Using SST, connect terminals Tc and CG of DLC3.
SST 09843±18040
(4) ON and OFF the terminal Tc of DLC3 20 times within
20 sedonds.
(5) Check that the DTC C1515/15.
(d) In case of using TOYOTA hand±held tester:
Perform the torque sensor zero point calibration.
HINT:
Don't touch the steering wheel.
(1) Select the ºTRQ SENS ADJUSTº mode on the TOY-
OTA hand±held tester.
(2) Select the ºZERO POINT ADJUSTº.
(3) Following the screen instructions, perform the
torque sensor zero point calibration.
HINT:
Please refer to the TOYOTA hand±held tester operator's manu-
al for further details.
(e) In case of not using TOYOTA hand±held tester:
Perform the torque sensor zero point calibration.
HINT:

Don't touch the steering wheel.

Check the DTC except C1515/15 is not output.
(1) Stop the vehicle and turn the ignition switch OFF.

DI7QX±01
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±465
2001 PRIUS (RM778U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:

Using SST 09843±18040, connect terminals Tc and CG of the DLC3.

If a malfunction code is displayed during the DTC check, check the circuit listed for the code. For details
of each code, turn to the page referred to under the ºSee pageº for respective ºDTC No.º in the DTC
chart.
DTC No.
(See page)Detection ItemTrouble Area
C1511/11
(DI±465)
C1512/12
(DI±465)
T i it lf ti
Torque sensor
C1513/13
(DI±465)Torque sensor circuit malfunction
Torque sensor

EMPS ECU
C1514/14
(DI±465)
C1521/21
(DI±471)
C1522/22
(DI±471)
Mt i it lf ti
Power steering gear assembly with motor
C1523/23
(DI±471)Motor circuit malfunction
Power steering gear assembly with motor

EMPS ECU
C1524/24
(DI±471)
C1531/31
(DI±473)
C1532/32
(DI±473)EMPS ECU malfunctionEMPS ECU
C1533/33
(DI±473)
C1541/41
(DI±474)
C1542/42
(DI±474)Speed sensor malfunction

Speed sensor

Brake ECU

EMPS ECUC1543/43
(DI±474)
EMPS ECU
C1551/51
(DI±476)IG power source circuit malfunction

EMPS ECU

Power source circuit

Charging system
C1552/52
(DI±479)PIG power source drop voltage malfunction
EMPS ECU

Power source circuit
C1553/53
(DI±482)When resetting voltage, vehicle is being drivenEMPS ECU
C1554/54
(DI±483)EMPS relay circuit malfunction

EMPS relay

EMPS ECU

EMPS relay circuit
C1555/55
(DI±473)EMPS ECU malfunctionEMPS ECU
C1556/56
(DI±486)P/S warning light circuit
Multiinformation display

EMPS ECU

DI7R1±01
F12832
I01
E3
E3
E3
E31
4
2
3EMPS ECU
TRQV
TRQ1
TRQ2
TRQG (Shielded)
W
R
G
B 1 2
3
4 VCC
VT1
VT2
GND Steering Shaft
Torque Sensor
W±B 5
J/C
J18 J19AA
W±B W±B
J17 J/C
A
IG DI±470
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
2001 PRIUS (RM778U)
CIRCUIT INSPECTION
DTC
C1511/11±C1514/14Torque Sensor Circuit Malfunction
CIRCUIT DESCRIPTION
Steering torque is detected from output current of torque sensor.
DTC No.Detection ItemTrouble Area
C1511/11
C1512/12Torque sensor malfunction
Power steering gear assembly with motor
C1513/13
Torque sensor malfunction
Power steering gear assembly with motor

EMPS ECU
C1514/14Open or short torque sensor circuit
WIRING DIAGRAM

F12270
ON
TRQV
TRQG
F12271
VT1
VT2
GND
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±471
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check voltage between terminals TRQV and TRQG of EMPS ECU.
PREPARATION:
Remove the EMPS ECU with connectors still connected.
CHECK:
Measure the voltage between terminals TRQV and TRQG of
EMPS ECU connector.
OK:
Voltage: 4.5 ± 5.5 V
NG Check and replace the EMPS ECU.
OK
2 Check for open and short circuit in harness and connector between terminals
TRQV and TRQG of EMPS ECU connector (See page IN±41).
NG Repair and replace harness or connector.
OK
3 Check voltage between terminals VT1 and GND, VT2 and GND of torque sensor
connector.
PREPARATION:
Remove the torque sensor with connectors still connected.
CHECK:
Measure the voltage between terminals VT1 and GND, VT2 and
GND of torque sensor connector.
OK:
Steering PositionVT1VT2
Center position2.1 ± 2.9 V2.1 ± 2.9 V
Right turned0.15 ± 2.9 V2.1 ± 4.85 V
Left turned2.1 ± 4.85 V0.15 ± 2.9 V