2001 TOYOTA PRIUS Service Repair Manual

H03354H16253H16297
Airbag
Sensor
Assembly Front Airbag
Sensor (LH)
(+)
+SL
(±)
±SL
ON
Engine Room Main
Wire Harness
u"
H03354H16252H16298
Airbag
Sensor
Assembly Front Airbag
Sensor (LH)
(+)+SL
(±)±SL Engine Room Main
Wire Harness
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±631
2001 PRIUS (RM778U)
8 Check engine room main wire harness (to B+).
PREPARATION:
Disconnect the engine room main wire harness connector on
the airbag sensor assembly side.
CHECK:
(a) Turn the ignition switch to ON.
(b) For the connector (on the LH front door wire harness side)
between the airbag sensor assembly and the engine
room main wire harness, measure the voltage between
body ground and each of +SL and ±SL.
OK:
Voltage: Below 1 V
NG Repair or replace engine room main wire har-
ness.
OK
Repair or replace harness or connector between airbag sensor assembly and engine room main
wire harness.
9 Check engine room main wire harness (to ground).
PREPARATION:
Disconnect the engine room main wire harness connector on
the airbag sensor assembly side.
CHECK:
For the connector (on the engine room main wire harness side)
between the airbag sensor assembly and the engine room main
wire harness, measure the resistance between body ground
and each of +SL and ±SL.
OK:
Resistance: 1 MW or Higher
NG Repair or replace engine room main wire har-
ness.
OK
Repair or replace harness or connector between airbag sensor assembly and engine room main
wire harness.

H03354H16251H16299
Airbag
Sensor
Assembly
Front Airbag
Sensor (LH)
(±) +SL
±SL
Engine Room Main
Wire Harness
(+)
u "
DI±632
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
10 Check engine room main wire harness.
PREPARATION:
Disconnect the engine room main wire harness connector on
the airbag sensor assembly side.
CHECK:
For the connector (on the engine room main wire harness side)
between the airbag sensor assembly and the engine room main
wire harness, measure the resistance between +SL and ±SL.
OK:
Resistance: 1 MW or Higher
NG Repair or replace engine room main wire har-
ness.
OK
Repair or replace harness or connector between airbag sensor assembly and engine room main
wire harness.

H03352H16251H03360H16300
Airbag
Sensor
Assembly Front Airbag
Sensor (LH)
(+) +SL
(±)±SL
Engine Room Main
Wire Harness
+SL
±SL
u "
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI±633
2001 PRIUS (RM778U)
11 Check engine room main wire harness.
PREPARATION:
(a) Disconnect the engine room main wire harness connector
on the airbag sensor assembly side.
(b) Using a service wire, connect +SL and ±SL of the connec-
tor (on the engine room main wire harness side) between
the engine room main wire harness and the front airbag
sensor (LH).
CHECK:
For the connector (on the engine room main wire harness side)
between the airbag sensor assembly and the engine room main
wire harness, measure the resistance between +SL and ±SL.
OK:
Resistance: Below 1 W
NG Repair or replace engine room main wire har-
ness.
OK
Repair or replace harness or connector between airbag sensor assembly and engine room main
wire harness.

H15524
B±W
W5
2BB±O
GR
W±B ACC Relay 10A SRS ACC
5A AM1
FL Block No. 2 FL Block No. 1 15A AM2
Battery 100A
DC/DCB±G W±RA
J11
J/C W±G
W±R P±L1
2H
8
2C2
2E
4
2E
8
2K
2B 536
A18ACC
120A
1 1
F13 1
F12
1
F11 1B9 2
1J B1
2G2
2C ACC
2
67AM1
AM2 IG2MAIN
35
A18IG2 Airbag Sensor
Assembly Instrument Panel J/B
Ignition Switch
ID 12
3
Instrument Panel J/B Engine Room J/B DI±634
± DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
2001 PRIUS (RM778U)
DTC Normal Source Voltage Drop
CIRCUIT DESCRIPTION
The SRS is equipped with a voltage±increase circuit (DC±DC converter) in the airbag sensor assembly in
case the source voltage drops.
When the battery voltage drops, the voltage±increase circuit (DC±DC converter) functions to increase the
voltage of the SRS to normal voltage.
The diagnosis system malfunction display for this circuit is different from other circuits that is when the SRS
warning light remains lit up and the DTC is a normal code, source voltage drop is indicated.
Malfunction in this circuit is not recorded in the airbag sensor assembly, and the source voltage returns to
normal, the SRS warning light automatically goes off.
DTC No.Diagnosis
(Normal)Source voltage drop
WIRING DIAGRAM
DI6PY±07