2001 TOYOTA PRIUS lights

F12683
Brake ECU
Instrument Panel J/B GAUGE 4
IH L FL Block No. 1
1
BatteryIgnition Switch
2
2
2K2A18
W
3AM1IP1
AABS
2A14 2B F11
C10
J11
J/CB±W
5WA
W±B W±G
2H 2D DC/DC
B±Y
1
FL Block
No. 2 B±G
F131
B11
1C10
C10L2
10
22
5 1
3
6
87
LCommbination
Mater
2B 6
IDBR MAIN DI±442
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
ABS Warning Light Circuit
CIRCUIT DESCRIPTION
If the ECU detects trouble, it lights the ABS warning light while at the same time prohibiting ABS control. At
this time, the ECU records a DTC in memory.
Connect terminals Tc and CG of the DLC3 to make the ABS warning light blink and output the DTC.
WIRING DIAGRAM
DI29F±14

F12684
Brake Fluid Level
Warning Switch
IG1
Relay FL Block No. 2
Body ECU
Multiplex Communication CircuitR±Y
BrakePKB
E
83
GAUGE5
WJ12
J/C Parking
Brake Switch
2 1
1C10
2A7
LG±R
A 4BRL Brake ECU
W±GB12
6
Battery
IE LBL B12 B1113
R±Y R±Y
R±Y E
J7
J/C
J1
J/C
J11
J/C 2D2B
2H2K
2K5
23 15
2A7 AM1
C10C11C11
143
2
22 2
W±BB±Y
L
BRA A
A
W±BW±B 21 IA2 18
MAIN
B±GFL Block No. 1
111
DC/DC
F13 F11
B8 B8 15 164 Instrument
Panel J/B
LGR GR±B Ignition Switch
Instrument
Panel J/B
Commbination Meter
2B6
IH ID DI±446
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM WITH EBD & RBS
2001 PRIUS (RM778U)
BRAKE Warning Light Circuit
CIRCUIT DESCRIPTION
The BRAKE warning light lights up when the brake fluid is insufficient, the parking brake is applied or the
EBD is defective.
The BRAKE warning light also lights up when DTC No. C1213/63 or C1259/59 is detected, however, the EBD
is not inhibited in this case.
WIRING DIAGRAM
DI29G±14

DI7QW±01
F12845
F12874
F12846
Tc
CG
F12873
WL
PGND
± DIAGNOSTICSELECTRIC MOTOR POWER STEERING
DI±459
2001 PRIUS (RM778U)
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Check the indicator.
When the ignition switch is turned ON, check that the PS
warning light goes on for 1.5 seconds.
HINT:

If the indicator check result is not normal, proceed to trou-
bleshooting for the PS warning light circuit (See page
DI±486).

When the EMPS system is faulty, the master warning light
in the combination meter and the PS warning light in the
multiinformation display lights up.
(b) In case of not using TOYOTA hand±held tester:
Check the DTC.
(1) Using SST, connect terminals Tc and CG of the
DLC3.
SST 09843±18040
(2) Remove the EMPS ECU with connector still con-
nected.
(3) Connect the both terminals of the 1kW resistance
and LED (Light Emitting Diode) circuit to terminals
WL and PGND of the EMPS ECU.
(4) Turn the ignition switch ON.
(5) Read the DTC from the PS warning light.

DI6OY±07
H15218
H10658
DLC3
CG Tc
DI±502
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
PRE±CHECK
1. SRS WARNING LIGHT CHECK
(a) Turn the ignition switch to the ON position and check that
the SRS warning light lights up.
(b) Check that the SRS warning light goes out after approx.
6 seconds.
HINT:

When the ignition switch is at ON and the SRS warning
light remains on or flashes, the airbag sensor assembly
has detected a malfunction code.

If, after approx. 6 seconds have elapsed, the SRS warn-
ing light sometimes lights up or the SRS warning light
lights up even when the ignition switch is OFF, a short in
the SRS warning light circuit can be considered likely.
Proceed to ºSRS warning light circuit malfunctionº on
page DI±632.
2. DTC CHECK (Using diagnosis check wire)
(a) Present troubles codes:
Output the DTC.
(1) Turn the ignition switch to the ON position and wait
for approx. 20 seconds.
(2) Using SST, connect terminals Tc and CG of the
DLC3.
SST 09843±18020
NOTICE:
Pay due attention to the terminal connecting position to
avoid a malfunction.
(b) Past troubles codes:
Output the DTC.
(1) Using service wire, connect terminals Tc and CG of
the DLC3.
SST 09843±18020
(2) Turn the ignition switch to the ON position and wait
for approx. 20 seconds.
NOTICE:
Pay due attention to the terminal connecting position to
avoid a malfunction.

H15525
Combination Meter
Instrument Panel J/B
10A ACC
ACC Relay
5A AM1
W±G L15
C10
16
C10
5
C11
GR±RGR±R
W±BB±Y 9
2A
2
2D
8
2A
1
2H
8
2C
3
2B53
128
2K4
2B 1
2E3
A18LA
1
F11C
J27
Fl Block No. 1
23P±LW 1
F13
1 B±GL
GR±R
BBC
J28AB
A
J11
J/C
Battery F18
FL
Block
No. 2DLC3
DC/DC100A
J/C
I15 Ignition S/W
120A
MAINAirbag Sensor
Assembly
B±Y6
ID J26
J/C
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±637
2001 PRIUS (RM778U)
SRS Warning Light Circuit Malfunction
CIRCUIT DESCRIPTION
The SRS warning light is located on the combination meter.
When the SRS is normal, the SRS warning light lights up for approx. 6 seconds after the ignition switch is
turned from the LOCK position to ON position, and then turns off automatically.
If there is a malfunction in the SRS, the SRS warning light lights up to inform the driver of the abnormality.
When terminals Tc and CG of the DLC3 are connected, the DTC is displayed by blinking the SRS warning
light.
WIRING DIAGRAM
DI7QT±01

AB0117H01293H01295
Airbag Sensor Assembly
LOCK
DI±638
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
Always lights up, when ignition switch is in LOCK position
1 Prepare for inspection (See step 1 on page DI±629).
2 Does SRS warning light turn off?
PREPARATION:
(a) Turn the ignition switch to LOCK.
(b) Disconnect negative (±) terminal cable from the battery,
and wait at least for 90 seconds.
(c) Disconnect the airbag sensor assembly connector.
(d) Connect negative (±) terminal cable to the battery.
CHECK:
Check operation of SRS warning light.
NO Check SRS warning light circuit or terminal A/B
circuit of DLC3.
YES
Replace airbag sensor assembly.

I15479
Combination Meter
FL Block No. 1Instrument Panel J/B
to Body ECU 5A AM1IG1
Relay
3
GR±B14
C10
2A
CRUISE 8
W±B
B±G22
C10 L
2K8
2
C11
W±B I15 Ignition SW
AM1
IG1
F11
Battery
ID 10A GAUGE
5
AJ11
J/C 2 1 2B6
2B3
2D6 W
W±G
B±Y
24
B±Y
1F13
1F18
1FL Block No. 2
120A MAIN
100A DC/DC7
2A
1
2H
IH BR
± DIAGNOSTICSCRUISE CONTROL SYSTEM
DI±665
2001 PRIUS (RM778U)
CRUISE MAIN Indicator Light Circuit
CIRCUIT DESCRIPTION
When the cruise control main switch is turned ON, CRUISE MAIN indicator light lights up.
WIRING DIAGRAM
DI7NL±01

DI7XS±01
DI±674
± DIAGNOSTICSCOMBINATION METER SYSTEM
2001 PRIUS (RM778U)
PROBLEM SYMPTOMS TABLE
TROUBLESHOOTING:
Flow chart No.SymptomSee page
1Check the communication between the combination meter and the multiplex com-
munication circuit.DI±671
2The whole meter does not functionDI±672
3The margin of error in speedometer is large. Or it remains as 0 mph.DI±673
4Fuel receiver gauge is inoperative or improper.DI±674
5Indicators or warning lights do not light up.DI±676
Fuel gauge:
SymptomSuspect AreaSee page
Displayed level is higher or lower than the actual level.1. Inclination sensor resetting
2. Body ECUBE±47
IN±41
General:
SymptomSuspect area
Meter display does not properly function.3. Combination meter ECU
Entirely black screen appears.1. Fuse
2. Wire harness and connector
3. Combination meter ECU
Turning the light control switch ON does not dim the light.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Brightness cannot be changed by the illumination switch operation.1. Illumination switch
2. Wire harness and connector
3. Combination meter ECU
Speedometer:
SymptomSuspect area
Improper display (Remained as 0 km/h)1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Speedometer only does not light up.1. Combination meter ECU
Abnormal display (Incomplete numbers displayed)1. Combination meter ECU
DIsplayed value changes frequently or sharply.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
Margin of error in speedometer is large.1. Accessory that utilizes vehicle speed signals
2. Brake ECU
3. Combination meter ECU
4. Wire harness and connector
ODO/TRIP Meter:
SymptomSuspect area
ODO/TRIP only does not light up.1. Combination meter ECU
Abnormal display (Incomplete number displayed)1. Combination meter ECU
Both meters do not integrate values. (When speedometer is normal)1. Combination meter ECU
Trip meter only does not integrate values.1. ODO/TRIP switch
2. Combination meter ECU