2001 TOYOTA PRIUS Service Repair Manual

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±241
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open and short in wire harness between HV ECU terminals (ETH+,
ETH±) and ECM terminals (ETH+, ETH±) (See page IN±41).
NG Repair or replace wire harness.
OK
Replace ECM.
CIRCUIT DESCRIPTION
DTC P3106 ± Information code 212
INF. Code.Detecting ConditionTrouble Area
212Input of abnormal signal from ECM
ECM
INSPECTION PROCEDURE
If the information code 212 is output, after confirming the DTC of the ECM, check and repair the applicable
DTC. Prior to repairing it, record the DTC of the HV ECU, freeze frame data and history of operation. Then,
clear the DTC and check it one more time after starting the system again (ºREADYº light ON).
CIRCUIT DESCRIPTION
DTC P3106 ± Information code 394
INF. Code.Detecting ConditionTrouble Area
394When ECM does not operate
ECM
INSPECTION PROCEDURE
If the information code 394 is output, check and repair the ECM power source circuit. If there is no problem
in the power source circuit, replace the ECM. Prior to the repair, record the DTC of the HV ECU, freeze frame
data and history of operation and clear them. Then, start the system one more time (ºREADYº light ON) and
check the DTC again.

A14139
Hybrid Vehicle
Control ECU
3
H13ABFS L 23
A18 GSW2 Airbag Sensor
Assembly DI±242
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
DTC P3107 Airbag ECU Communication Circuit Mal-
function
CIRCUIT DESCRIPTION
The HV ECU detects the malfunction of the collision signal circuit from the airbag and gives warning to the
driver.
DTC P3107 ± Information code 213, 214, 215
INF. Code.Detecting ConditionTrouble Area
213
214When communication between airbag ECU and HV ECU is
abnormal 10 sec after ignition is turned ON

Wire harness

Airbag sensor assembly215abnormal 10 sec. after ignition is turned ON
Airbag sensor assembly
WIRING DIAGRAM
DI832±02

± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±243
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU ABFS ter-
minals and airbag ECU GSW 2 terminal (See page IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the battery voltage is always applied to the HV
ECU ABFS terminal with the ignition ON, the airbag signal circuit has +B short.
NG Repair or replace wire harness.
OK
Replace airbag sensor assembly.

A14137
Hybrid Vehicle
Control ECU
20
H14
HTB+
HTB±
BTH+
BTH± Brake ECU
30
H14
18
H14
17
H14 LG
V
G
R 24
B11
16
B11
14
B11
22
B11 HV1+
HV1±
HVO+
HVO±
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±245
2001 PRIUS (RM778U)
DTC P3109 Brake ECU Communication Circuit Malfunc-
tion
CIRCUIT DESCRIPTION
The HV ECU performs multiple checks to avoid any malfunction that may occur through the communication
with the brake ECU due to a noise, etc.
HINT:

When using an OBD scan tool other than TOYOTA hand±held tester, check all the steps.

When using TOYOTA hand±held tester, confirm the information code and check it.
DTC P3109 ± Information code 218, 219, 220, 221
INF. Code.Detecting ConditionTrouble Area
218
219When communication between brake ECU and HV ECU is
b l 1 5 ft i iti i t d ON
Wire harness
220abnormal 1.5 sec. after ignition is turned ON
Wire harness

Brake ECU
221
WIRING DIAGRAM
DI834±02

DI±246
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
2001 PRIUS (RM778U)
INSPECTION PROCEDURE
1 Check for open, short and +B short in wire harness between HV ECU terminals
(HTB+, HTB±, BTH+, BTH±) and brake ECU terminals (HV1+, HV1±, HVO+, HVO±)
(See page IN±41).
HINT:
Confirm that there is no open circuit in the wire harness. If the voltage of each HV ECU terminals (HTB+,
HTB±, BTH+ and BTH±) is always more than 5 V with the ignition ON, the brake ECU communication circuit
has +B short.
NG Repair or replace wire harness.
OK
Replace brake ECU.
CIRCUIT DESCRIPTION
DTC P3109 ± Information code 222
INF. Code.Detecting ConditionTrouble Area
222When abnormal data is received from brake ECU.
Brake ECU
INSPECTION PROCEDURE
If the information code 222 is output, after confirming the DTC of the brake ECU, check and repair the appli-
cable DTC. Prior to repairing it, record the DTC of the HV ECU, freeze frame data and history of operation.
Then, clear the DTC and check it one more time after starting the system again (ºREADYº light ON).

A14737
Hybrid Vehicle
Control ECU Engine Room R/B No. 2
Fusible Link
Block No. 1
Battery+B1
MREL 4
H14
1FG±Y
W±G
O 2
7
H12 W±G12
IA1
2 2
2
213 5
Engine
Room J/B 11
HV
F12B±GMAIN 1B 1
B
F13Fusible Link
Block No. 2
1
F18 A
J7
J/C
W±B
IE
EC W±B W±B
AJ1
J/C
AA IGCT Relay
± DIAGNOSTICSHYBRID VEHICLE CONTROL SYSTEM
DI±247
2001 PRIUS (RM778U)
DTC P3110 IGCT Relay Malfunction
CIRCUIT DESCRIPTION
The HV ECU checks the IGCT relay and detects malfunction.
DTC P3110 ± Information code 223
INF. Code.Detecting ConditionTrouble Area
223
When IGCT relay is always closed.
Wire harness

IGCT relay
WIRING DIAGRAM
DI835±02