2001 TOYOTA PRIUS Service Repair Manual

A14464
VSV is ONVSV is OFF
Air FilterAir Filter
FE
F E
DI±94
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
Replace VSV and charcoal canister, and then clean vacuum hose between charcoal canister and
VSV for CCV.
20 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for CCV, and VSV for CCV and ECM (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±41).
21 Connect TOYOTA hand±held tester and check operation of VSV purge flow
switching valve.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand±
held tester main switch ON.
(c) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
CHECK:
Check operation of VSV when VSV is operated by the TOYOTA
hand±held tester.
OK:
VSV is ON:
Air from pipe E is flowing out through pipe F.
VSV is OFF:
Air from pipe E is flowing out through the air filter.
OK Go to step 24.
NG
22 Check VSV for purge flow switching valve (See page SF±45).
NG Go to step 23.

BE6653A10620A14040A14045
START
ON
OFFVSV for EVAP
1.2 V ON
OFF
E2
PTNK
(±) (+)
VSV for CCV
Measure
Voltage30 sec.
± DIAGNOSTICSENGINE
DI±95
2001 PRIUS (RM778U)
OK
Replace VSV and charcoal canister, and clean vacuum hoses ((1), (2) and (3) in Fig. 1 in circuit
description.
23 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for purge flow switching valve, and VSV for purge flow
switching valve and ECU (See page IN±41).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±41).
24 Check fuel tank and charcoal canister.
PREPARATION:
(a) Remove the connector cover from the ECM.
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
(d) Start the engine.
(e) The VSV for the CCV is ON by the TOYOTA hand±held
tester.
(f) The VSV for the EVAP is ON by the TOYOTA hand±held
tester and hold the VSV for EVAP until voltage between
terminals PTNK and E2 becomes 1.2 V, then set VSV for
EVAP OFF.
CHECK:
Measure the voltage between terminals PTNK and E2 of the
ECM connectors 30 sec. after switching the VSV for the EVAP
from ON to OFF.
OK:
Voltage: 2.3 V or less
OK Check and replace ECM.
NG

DI±96
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
25 Remove fuel tank and check it.
NG Replace fuel tank.
OK
26 Remove charcoal canister and check it (See page EC±7).
NG Replace charcoal canister.
OK
Check and replace ECM (See page IN±41).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check whether hose close to fuel tank have been modified, and check whether
there are signs of any accident near fuel tank or charcoal canister (See page
DI±81).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts.
NG Replace to TOYOTA genuine parts.
OK
3 Check that fuel tank cap is correctly installed.
NG Correctly install fuel tank cap.

± DIAGNOSTICSENGINE
DI±97
2001 PRIUS (RM778U)
OK
4 Check fuel tank cap (See page EC±7).
NG Replace fuel tank cap.
OK
5 Check filler neck for damage.
NG Replace filler pipe.
OK
6 Check VSV connector for EVAP, VSV connector for CCV, VSV connector for
purge flow switching valve and vapor pressure sensor connector for looseness
and disconnection.
NG Repair or connect VSV or sensor connector.
OK
7 Check vacuum hoses ((1), (2) , (3), (4), (5), (6), (7), (8) and (9) in Fig. 1 in circuit
description).
CHECK:
(a) Check that the vacuum hose is connected correctly.
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole damage and blockage.
NG Repair or replace.
OK

DI±98
± DIAGNOSTICSENGINE
2001 PRIUS (RM778U)
8 Check voltage between terminals VC and E2 of ECM connector (See page
DI±81).
NG Check and replace ECM (See page IN±41).
OK
9 Check voltage between terminals PTNK and E2 of ECM connectors (See page
DI±81).
OK Go to step 11.
NG
10 Check for open and short in harness and connector between vapor pressure
sensor and ECM (See page IN±41).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.