2005 TOYOTA AVENSIS Circuit

A81485
Fuel Pressure
Pressure Discharge Valve Operation Under Sudden Deceleration
Pressure Discharge Valve w/o Pressure Discharge Valve
Close
Accelerator Pedal
Opening Angle
Open
Close
Open
w/ Pressure Discharge Valve
TargetFuel Pressure TimeLong Time
±
DIAGNOSTICS ECD SYSTEM(1CD±FTV)
05±663
AVENSIS REPAIR MANUAL (RM1018E)
DTCP1271FUEL REGULATOR CIRCUIT MALFUNCTION
(EDU DRIVE)
DTCP1272FUEL PRESSURE REGULATOR MALFUNCTION
HINT:

For more information on the pressure discharge valve and the common rail sy\
stem, see page 05±517.

For more information on the EDU, see page 05±604.

If P1271 and/or P1272 are present, use the diagnostic trouble code matrix for fuel syste\
m, see page
05±517.
CIRCUIT DESCRIPTION
The ECM controls the internal fuel pressure of the common rail by opening a\
nd closing the pressure dis-
charge valve. When sudden deceleration is occurred, the internal fuel pressure will temporarily become
higher than usual and combustion noise may result, therefore the ECM will open the valve temporarily to
discharge the pressure inside the common rail. Also, the pressure discharge valve open\
s when the ignition
switch is turned OFF, and the internal pressure is then promptly discharged.
05CQ1±01

A81505
Pressure Discharge Valve Cross Section Diagram
From Common Rail
(High Pressure)To Fuel Tank
(Low Pressure)
Valve
Solenoid
05±664
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
AVENSIS REPAIR MANUAL (RM1018E)
HINT:
The solenoid valve of the pressure discharge valve is the same type of the injector solenoid valve.
DTC No.DTC Detection conditionTrouble Area
P1271
Open or short in pressure discharge valve circuit. There is no
valve opening confirmation signal (IJF) from EDU to ECM,
despite the ECM sending valve opening command signal
(PRD) after the engine has been started (1 trip detection).
Open or short in pressure discharge valve circuit

Open or short in pressure discharge valve itself

EDU

ECM
P1272
Pressure discharge valve closed malfunction. Actual pressure
decreasing rate deviates from the simulated pressure drop rate
by the ECM after the ignition switch is turned OFF (2 trip detec-
tion).
Open or short in pressure discharge valve circuit (P1271 is
set simultaneously)

Pressure discharge valve

Supply pump

ECM
HINT:
After confirming DTC ºP1271 and/or P1272º, use the hand±held tester to confirm the fuel pressure inside
common rail in the ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALL / COMN RAIL PRESSº.
Engine SpeedFuel Pressure (MPa)
IdlingApprox. 30 to 40
Running the engine at 2,500 rpm (No engine load)Approx. 50 to 100

A81500
P1271 Malfunction Detection
ECMCommand Signal (PRD)
EDU
Confirmation Signal (IJF)
Pressure Discharge Valve
Command Signal
Pressure Discharge Valve
Confirmation SignalPRD
IJFON
OFF
Normal
Abnormal
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
05±665
AVENSIS REPAIR MANUAL (RM1018E)
MONITOR DESCRIPTION
P1271 (Open or short in pressure discharge valve circuit):
This DTC will be set if there is no valve opening confirmation signal (IJF) from the EDU to the ECM, despite
the ECM commanding the pressure discharge valve to open with the EDU. This DTC refers to open or short
malfunction of the pressure discharge valve circuit, therefore the malfunction that the valve is stuck open
or closed can be excluded.
The EDU monitors the current supplied to the pressure discharge valve, and the EDU interprets the IJF sig-
nal is low if the current exceeds the specified level, and the EDU indicates that there is the current in the
pressure discharge valve.
If this DTC is present, the ECM enters fail±safe mode and limits the engine power. The fail±safe mode will
continue until the ignition switch is turned OFF.
P1272 (Closed malfunction of the pressure discharge valve):
The pressure discharge valve will open and discharge the internal fuel pressure of the common rail to the
fuel tank when the ignition switch is turned OFF. In this event, the ECM compares the actual dropping rate
of the internal fuel pressure and the simulated dropping rate. If the ECM judges the actual dropping rate is
smaller than the simulation, the ECM then interprets this as the valve has stuck closed and set this DTC.
This DTC detection will be activated if the internal fuel pressure does not drop below the specified level after
the ignition switch has been turned OFF.
If this DTC is present, the ECM enters fail±safe mode and limits the engine power. The fail±safe mode will
continue until the ignition switch is turned OFF.
MONITOR STRATEGY
P1271:
Required sensorsEDU
Frequency of operationContinuous
Duration3 sec.
CHK ENG operation1 driving cycles

05±666
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
AVENSIS REPAIR MANUAL (RM1018E)
P1272:
Required sensorsFuel pressure sensor
Frequency of operationOnce per driving cycle
Duration1 sec.
CHK ENG operation2 driving cycles
TYPICAL ENABLING CONDITIONS
P1271:
Specification
Drive the vehicle at 50 km/h with the 3 rd transmission gear and then decelerate it by completly releasing the accelerator pedal
P1272:
ItemSpecificationItemMinimumMaximum
Fuel pressure30 MPa (306 kgf/cm2, 4,351 psi)±
Fuel temperature0
C±
Battery voltage11 V±
The monitor will not run if the fuel pressure sensor, or pressure discharge valve circuit, or fuel temp. sensor is malfunctioning
TYPICAL MALFUNCTION THRESHOLDS
P1271:
Threshold
If the confirmation signals from the EDU is not present, despite the ECM sending the command signals regularly during decelerating
P1272:
Threshold
If the internal pressure stays beyond the specified level after the ignition switch was turned OFF

A80999
EDU
1 R±L
PRDECM
E1332
1
EA1 PRDR±L
E54
W
PRVE58
B
COM3
E472 P3
Pressure Discharge Valve
W
B 2
EA1
(Shielded) (Shielded)
BR
BR
BR
EIJ12D
J12E
J13D J13E J/C
A81507
ECMEDU
PRD
Pressure
Discharge
Valve
INJFCOM3 A
PRD
IJFPRV B
C
D
Warning: Terminals COM3 and PRD are high±voltage
High±voltage Area
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
05±667
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
PULSE GENERATION INSPECTION
HINT:
Problem area can be identified by inspecting waveform at the following inspection points.
HINT:
Inspect the following inspection points ºA and Dº or ºB and Cº at the same time.
Malfunction pointTrouble area
A
ECM
B (If A is normal)
Open or short in ºPRD (ECM)º ± ºPRD (EDU)º circuit.
C (If A and B are normal)

Open or short in ºPRV (EDU)º ± ºCOM3 (EDU)º circuit.

Pressure discharge valve

EDU
D (If A, B and C are normal)
Open or short in ºIJF (EDU)º ± ºINJF (ECM)º circuit. (P0200 is set simultaneously)

A81462
E5
Wire Harness Side
EDU ConnectorPRD
A81089ECM Connector E13
PRD
A56874
E4
Wire Harness Side
EDU ConnectorBATTERY (+)
A80994
E5
Wire Harness Side
EDU Connector GND (±)
05±670
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
AVENSIS REPAIR MANUAL (RM1018E)
4 CHECK HARNESS AND CONNECTOR(EDU ± ECM)
(a) Disconnect the E5 EDU connector.
(b) Disconnect the E13 ECM connector.
(c) Check for continuity between the wire harness side con-
nector.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
PRD (E5±4) ± PRD±(E13±32)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
PRD (E5±4) or PRD (E13±32) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
5 INSPECT INJECTOR DRIVER(BATTERY VOLTAGE)
(a) Disconnect the E4 and E5 EDU connectors.
(b) Turn the ignition switch ON.
(c) Measure the voltage between the specified terminals of
the EDU connector.
Voltage:
Symbols (Terminal No.)Specified condition
BATTERY (E4±8) ± GND (E5±1)9 to 14 V
NG CHECK INJECTOR DRIVER POWER SOURCE
CIRCUIT (EDU ± BATTERY)
OK

A80997
S6
Suction Control ValveECM
E132
PCV+
2 1
LG LG±R
PCV± E131
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
05±655
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0627 FUEL PUMP CONTROL CIRCUIT / OPEN
CIRCUIT DESCRIPTION
DTC No.DTC Detection ConditionTrouble Area
P0627Open or short in suction control valve circuit for more than 0.5
sec. (1 trip detection logic).
Open or short in suction control valve circuit

Suction control valve

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using   
 . Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running
or stopped, the engine was warmed up or not, etc. at the time of the malfunction.
05CPZ±01

A81017
GeneratorGlow Plug ECMGLOW
Relay Battery
± DIAGNOSTICSECD SYSTEM (1CD±FTV)
05±651
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0622 GENERATOR FIELD ºFº TERMINAL CIRCUIT
CIRCUIT DESCRIPTION
While the generator is generating the current, the duty signal is sent from terminal M of the generator to the
ECM terminal ALT. The duty signal is used for detecting the open malfunction of the generator circuit and
DTC P0380.
DTC No.DTC Detection ConditionTrouble Area
P0622Generator terminal M duty signal is not output while engine is
running.

Open in generator circuit

Generator

Driver belt

ECM
MONITOR DESCRIPTION
The ECM will detect a generator failure or an open malfunction of the circuit, if the duty signal is not output
from terminal M of the generator despite the engine running.
MONITOR STRATEGY
Required sensorsGenerator circuit
Frequency of operationContinuous
Duration10 sec.
CHK ENG operation1 driving cycle
TYPICAL ENABLING CONDITIONS
ItemSpecificationItemMinimumMaximum
Battery voltage11 V±
Engine speed700 rpm2,000 rpm
TYPICAL MALFUNCTION THRESHOLDS
Threshold
There is no signal output from terminal M of the generator
05CQ7±01