Page 4937 of 5135
A79123
I13
Ignition Switch
4
6
IE4B–R
IP1 1
1(LHD)
B–R
11B–Y B–R
DHIGN
DA18 2Driver Side J/B
22
EFI
1 AM2
1
1A 1
B–GEngine Room
R/B No.1
Engine Room
J/B No.1 (RHD)
14A
14BEngine Room
J/B No.4
B–G
FL MAIN
BatteryB–W
(LHD)B–W
(LHD)
J8
J/C CC B–W
(RHD)B–W
(RHD)
J/C J26 J27AE
ECM
IGSW
E99
GR
IE12
GR
E104
MREL
44
51
EFI
Relay+B 1
E9 B–R
Engine Room
R/B No.4
Engine Room
R/B No.444
4
4E1 5
E13
IK1 8
1
2
EH
ECW–B
B–RBR B–W
EFI
No.132
B–R
EA1 12
– DIAGNOSTICSSFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
05–195
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
ECM POWER SOURCE CIRCUIT
CIRCUIT DESCRIPTION
When the ignition switch is turned to ON, the battery voltage is applied to terminal IGSW of the ECM. The
ECM ”MREL” output signal causes a current to flow to the coil, closing the contacts of the EFI relay and sup-
plying power to terminal +B of the ECM.
WIRING DIAGRAM
05KOF–02
Page 4938 of 5135

A18294
E1 (–)
+B (+)
ECM Connecter
E13
E9
A65743
E13
ECM Connector
E1
A18294
E1 (–)IGSW (+)
ECM Connecter
E9
E13
r
05–196
–
DIAGNOSTICS SFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
INSPECTION PROCEDURE
1 INSPECT ECM(+B VOLTAGE)
(a) Turn the ignition switch to ON.
(b) Measure the voltage between the terminals of the E9 and E13 ECM connectors.
Standard:
Tester ConnectionSpecified Condition
+B (E9–1) – E1 (E13–5)9 to 14 V
OK PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE
(See page 05–12 )
NG
2 CHECK HARNESS AND CONNECTOR(ECM – BODY GROUND)
(a) Disconnect the negative (–) battery cable.
(b) Disconnect the E13 ECM connector.
(c) Check the resistance. Standard (Check for open):
Tester ConnectionSpecified Condition
E1 (E13–5) – Body groundBelow 1 Ω
(d) Reconnect the ECM connector.
(e) Reconnect the negative battery cable.
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
3 INSPECT ECM(IGSW VOLTAGE)
(a) Turn the ignition switch to ON.
(b) Measure the voltage between the terminals of the E9 and E13 ECM connectors.
Standard:
Tester ConnectionSpecified Condition
IGSW (E9–9) – E1 (E13–5)9 to 14 V
OK Go to step 5
NG
Page 4939 of 5135

A79096
Driver Side J/B:
IGN Fuse
A18294
E01 (–)MREL (+)
ECM Connecter
E13E10
A96024
Engine Room R/B No. 1:
EFI Fuse
– DIAGNOSTICSSFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
05–197
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
4 CHECK FUSE(IGN FUSE)
(a) Remove the IGN fuse from the driver side J/B.
(b) Check the IGN fuse resistance.
Standard: Below 1 Ω
(c) Reinstall the IGN fuse.
NG CHECK FOR SHORT IN ALL HARNESSES AND
COMPONENTS CONNECTED TO FUSE
OK
CHECK AND REPAIR HARNESS AND CONNECTOR (BATTERY – ECM)
5 INSPECT ECM(MREL VOLTAGE)
(a) Turn the ignition switch to ON.
(b) Measure the voltage between the terminals of the E10
and E13 ECM connectors.
Standard:
Tester ConnectionSpecified Condition
MREL (E10–4) – E01 (E13–7)9 to 14 V
NG REPLACE ECM (See page 10–65 of Pub. No.
RM1018E AVENSIS)
OK
6 CHECK FUSE(EFI FUSE)
(a) Remove the EFI fuse from the engine room R/B No. 1.
(b) Check the EFI fuse resistance.
Standard: Below 1 Ω
(c) Reinstall the EFI fuse.
NG CHECK FOR SHORT IN ALL HARNESSES AND
COMPONENTS CONNECTED TO FUSE
OK
Page 4940 of 5135

B16200
A66053
Engine Room R/B No. 4:
EFI relay
A65744
MREL E10
ECM Connector
05–198
– DIAGNOSTICSSFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
7 INSPECT EFI RELAY
(a) Remove the EFI relay from the engine room R/B No. 4.
(b) Check the EFI relay resistance.
Standard:
Tester ConnectionSpecified Condition
3 – 510 kΩ or higher
3 – 5Below 1 Ω
(Apply battery voltage to terminals 1 and 2)
(c) Reinstall the EFI relay.
NG REPLACE EFI RELAY
OK
8 CHECK HARNESS AND CONNECTOR(EFI RELAY – ECM, EFI RELAY – BODY
GROUND)
(a) Check the harness and connectors between the EFI relay
and the ECM connector.
(1) Remove the EFI relay from the engine room R/B No.
4.
(2) Disconnect the E10 ECM connector.
(3) Check the resistance.
Standard (Check for open):
Tester ConnectionSpecified Condition
EFI relay (1) – MREL (E10–4)Below 1 Ω
Standard (Check for short):
Tester ConnectionSpecified Condition
EFI relay (1) or MREL (E10–4) – Body ground10 kΩ or higher
(4) Reinstall the EFI relay.
(5) Reconnect the ECM connector.
(b) Check the harness and connector between the EFI relay
and the body ground.
(1) Remove the EFI relay from the engine room R/B No.
4.
(2) Check the resistance.
Standard (Check for open):
Tester ConnectionSpecified Condition
EFI relay (2) – Body groundBelow 1 Ω
(3) Reinstall the EFI relay.
OK REPAIR OR REPLACE HARNESS OR
CONNECTOR
NG
CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF ECM – BATTERY POS-
ITIVE TERMINAL)
Page 4941 of 5135

05–192
–
DIAGNOSTICS SFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
DTC P2121 THROTTLE/PEDAL POSITION SENSOR/SWITCH ”D” CIRCUIT
RANGE/PERFORMANCE
HINT:
This DTC is related to the accelerator pedal position senso r.
CIRCUIT DESCRIPTION
Refer to DTC P2120 on page 05–184.
DTC No.DTC Detection ConditionTrouble Area
P2121
Conditions (a) and (b) continue for 0.5 seconds:
(a) Difference between VPA1 and VPA2 exceeds the threshold
(b) IDL is OFF Accelerator pedal position sensor circuit
Accelerator pedal position sensor
ECM
HINT:
When DTC P2121 is detected, check the output voltage of the accelerator peda\
l position sensor by selecting
Powertrain / Engine and ECT / Data List / Accelerator POS No. 1 and Accelerator POS No. 2 on the int\
elligent
tester ll.
Reference:
Accelerator Pedal Position (Voltage Output)
Trouble AreaAccelerator Pedal ReleasedAccelerator Pedal DepressedTrouble AreaAccelerator POS
No. 1Accelerator POS No. 2Accelerator POS No. 1Accelerator POS No. 2
Normal condition0.5 to 1.1 V1.2 to 2.0 V2.6 to 4.5 V3.4 to 5.0 V
VCP circuit open0 to 0.2 V0 to 0.2 V0 to 0.2 V0 to 0.2 V
VPA circuit open or ground short0 to 0.2 V1.2 to 2.0 V0 to 0.2 V3.4 to 5.0 V
VPA2 circuit open or ground short0.5 to 1.1 V0 to 0.2 V2.6 to 4.5 V0 to 0.2 V
EPA circuit open4.5 to 5.0 V4.5 to 5.0 V4.5 to 5.0 V4.5 to 5.0 V
WIRING DIAGRAM
Refer to DTC P2120 on page 05–184.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the intelligent tester II. Freeze frame data record the engine condition\
when
malfunctions are detected. When troubleshooting, freeze frame data can h\
elp determine if the vehicle was
moving or stationary, if the engine was warmed up or not, if the air–fuel ratio was lean \
or rich, and other data
from the time the malfunction occurred.
05B5S–05
Page 4942 of 5135

A84814
VCP2EP2
EP1
VCP1
Component Side (RHD):
12
5
64
3
Accelerator Pedal Position Sensor
A84814
VCP1 EP1
EP2
VCP2
12
5
64
3
Accelerator Pedal Position Sensor
Component Side (LHD):
A66060
VPA2 (+)
VPA (+)
EPA (–)
EPA2 (–)
ECM Connector
E9
–
DIAGNOSTICS SFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
05–193
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
1 INSPECT ACCELERATOR PEDAL ASSY(ACCELERATOR PEDAL POSITION
SENSOR)
(a) Disconnect the A20 accelerator pedal position sensor
connector.
(b) Measure the resistance between each pair of terminals. Standard (RHD):
Tester ConnectionSpecified Condition
EP1 (1) – VCP1 (4)2.25 to 4.75 k Ω at 20 C (68 F)
EP2 (3) – VCP2 (6)2.25 to 4.75 k Ω at 20 C (68 F)
Standard (LHD):
Tester ConnectionSpecified Condition
EP1 (3) – VCP1 (6)2.25 to 4.75 k Ω at 20 C (68 F)
EP2 (1) – VCP2 (4)2.25 to 4.75 k Ω at 20 C (68 F)
(c) Reconnect the accelerator pedal position sensor connec-
tor.
NG REPLACE ACCELERATOR PEDAL ASSY (See page 10–12 )
OK
2 INSPECT ECM(VPA AND VPA2 VOLTAGE)
(a) Turn the ignition switch to ON.
(b) Measure the voltage between the specified terminals of the E9 ECM connector.
Accelerator Pedal PositionTester ConnectionSpecified Condition
ReleasedVPA (E9–22)
– EPA (E9–28)0.5 to 1.1 V
DepressedVPA (E9–22) – EPA (E9–28)2.6 to 4.5 V
ReleasedVPA2 (E9–23) – EPA2 (E9–29)1.2 to 2.0 V
DepressedVPA2 (E9–23) – EPA2 (E9–29)3.4 to 5.0 V
OK REPLACE ECM (See page 10–65 of Pub. No.RM1018E AVENSIS)
NG
Page 4943 of 5135

A84847
EP1 EP2VPA2
VCP1 VPA1VCP2
A20
Wire Harness Side (RHD):
Front View
Accelerator Pedal Position Sensor
Connector
A84847
EP1
EP2VPA2
VCP1
VPA1
VCP2
A20
Accelerator Pedal Position Sensor
Connector
Wire Harness Side (LHD):
Front View
A81091
E9
ECM Connector VPA
VCPA
VPA2
EPA2 VCP2EPA
05–194
–
DIAGNOSTICS SFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
3 CHECK HARNESS AND CONNECTOR(ACCELERATOR PEDAL POSITION SENSOR – ECM)
(a) Disconnect the A20 accelerator pedal position sensor
connector.
(b) Disconnect the E9 ECM connector.
(c) Check the resistance. Standard (RHD) (Check for open):
Tester ConnectionSpecified Condition
VPA1 (A20–5) – VPA (E9–22)Below 1 Ω
EP1 (A20–1) – EPA (E9–28)Below 1 Ω
VCP1 (A20–4) – VCPA (E9–26)Below 1 Ω
VPA2 (A20–2) – VPA2 (E9–23)Below 1 Ω
EP2 (A20–3) – EPA2 (E9–29)Below 1 Ω
VCP2 (A20–6) – VCP2 (E9–27)Below 1 Ω
Standard (LHD) (Check for open):
Tester ConnectionSpecified Condition
VPA1 (A20–5) – VPA (E9–22)Below 1 Ω
EP1 (A20–3) – EPA (E9–28)Below 1 Ω
VCP1 (A20–6) – VCPA (E9–26)Below 1 Ω
VPA2 (A20–2) – VPA2 (E9–23)Below 1 Ω
EP2 (A20–1) – EPA2 (E9–29)Below 1 Ω
VCP2 (A20–4) – VCP2 (E9–27)Below 1 Ω
Standard (RHD) (Check for short):
Tester ConnectionSpecified Condition
VPA1 (A20–5) or VPA (E9–22) – Body ground10 kΩ or higher
EP1 (A20–1) or EPA (E9–28) – Body ground10 k Ω or higher
VCP1 (A20–4) or VCPA (E9–26) – Body ground10 k Ω or higher
VPA2 (A20–2) or VPA2 (E9–23) – Body ground10 k Ω or higher
EP2 (A20–3) or EPA2 (E9–29) – Body ground10 k Ω or higher
VCP2 (A20–6) or VCP2 (E9–27) – Body ground10 k Ω or higher
Standard (LHD) (Check for short):
Tester ConnectionSpecified Condition
VPA1 (A20–5) or VPA (E9–22) – Body ground10 k Ω or higher
EP1 (A20–3) or EPA (E9–28) – Body ground10 k Ω or higher
VCP1 (A20–6) or VCPA (E9–26) – Body ground10 k Ω or higher
VPA2 (A20–2) or VPA2 (E9–23) – Body ground10 k Ω or higher
EP2 (A20–1) or EPA2 (E9–29) – Body ground10 k Ω or higher
VCP2 (A20–4) or VCP2 (E9–27) – Body ground10 k Ω or higher
(d) Reconnect the accelerator pedal position sensor connec-
tor.
(e) Reconnect the ECM connector.
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE ACCELER ATOR PEDAL ASSY ( See page 10–12)
Page 4944 of 5135
05–184
– DIAGNOSTICSSFI SYSTEM (1ZZ–FE/3ZZ–FE)(From February, 2004)
AVENSIS REPAIR MANUAL SUPPLEMENT
(RM1098E)
DTC P2120 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”D” CIRCUIT
DTC P2122 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”D” CIRCUIT LOW INPUT
DTC P2123 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”D” CIRCUIT HIGH INPUT
DTC P2125 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”E” CIRCUIT
DTC P2127 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”E” CIRCUIT LOW INPUT
DTC P2128 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”E” CIRCUIT HIGH INPUT
DTC P2138 THROTTLE/PEDAL POSITION
SENSOR/SWITCH ”D”/”E” VOLTAGE
CORRELATION
HINT:
These DTCs are related to the accelerator pedal position sensor.
05KOD–02