wiring diagram TOYOTA TERCEL 1996 Service User Guide

A15696
FI6588
FI6538
A00064
10V/
Division
GND
100 m sec./Division (Idling)GND(Magnification)
1 m sec./Division (Idling)
Injection duration10V/
Division
- DIAGNOSTICSENGINE
DI-53
1996 TERCEL (RM440U)
WIRING DIAGRAM
Reference: INSPECTION USING OSCILLOSCOPE
INJECTOR SIGNAL WAVEFORM
With the engine idling, measure between terminals #10, #20 and E01 of ECM.
HINT:
The correct waveform is as shown.

A15700
- DIAGNOSTICSENGINE
DI-57
1996 TERCEL (RM440U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
A knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric
element which generates a voltage when it becomes deformed, which occurs when the cylinder block vi-
brates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No.DTC Detection ConditionTrouble Area
P0325
No knock sensor 1 signal to ECM with engine speed 1,200 rpm
or more
(2 trip detection logic)
Open or short in knock sensor 1 circuit

Knock sensor 1 (looseness)

ECM
If the ECM detects the above diagnosis conditions, it operates the fail-safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
DI012-20

A15703
DI-60
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0335 Crankshaft Position Sensor ºAº Circuit
Malfunction
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consists of a signal plate and pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals of every engine revolution. The ECM detects the standard crankshaft angle based on the G signals,
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detection ConditionTrouble Area
P0335
No crankshaft position sensor signal to ECM during
cranking (2 trip detection logic)
Open or short in crankshaft position sensor circuit.

Crankshaft position sensor
P0335No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more (2 trip detection logic)

Crankshaft osition sensor

Starter

ECM
WIRING DIAGRAM
DI013-24

- DIAGNOSTICSENGINE
DI-63
1996 TERCEL (RM440U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G signal) consist of signal plate and pickup coil.
The G signal plate has one tooth on its outer circumference and is mounted on the exhaust camshaft.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G signals
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detection ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM during cranking
(2 trip detection logic)
Open or short in camshaft position sensor circuit

Camshaft position sensor
P0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more

Camshaft osition sensor

Starter

ECM
WIRING DIAGRAM
Refer to DI-60.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor (See page IG-1).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to page DI-60.
NG Replace camshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN-26).
NG Repair or replace harness or connector.
OK
DI014-23

A15705
A15706
- DIAGNOSTICSENGINE
DI-65
1996 TERCEL (RM440U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temp. and reduce NOx
emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine load.
If even one of the following conditions is fulfilled, the VSV is
turned OFF by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut-off).

Before the engine is warmed up.

During deceleration (throttle valve closed).

Light engine load (amount of intake air very small).

Engine speed over 4,400 rpm.

Engine racing.
DTC No.DTC Detection ConditionTrouble Area
P0401
After the engine is warmed up, the intake manifold absolute
pressure is larger than the value calculated by the ECM while
the EGR system is ON.
(2 trip detection logic)

EGR valve stuck closed

Open or short in VSV circuit for EGR

Vacuum or EGR hose disconnected

Manifold absolute pressure sensor

EGR VSV open or close malfunction

ECM
WIRING DIAGRAM
DI95P-01

A15711
P19752
Combination Meter
C8611
SPD5 V
E8 Y
C9
7 Speed
Sensor
BR
ID
ECM DI-76
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This sensor is mounted in the combination meter. It contains a magnet which is rotated by the speedometer
cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedometer.
It is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of these
pulse signals.
DTC No.DTC Detection ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM when vehicle is being
driven
(2 trip detection logic)
Open or short in vehicle speed sensor circuit

Vehicle speed sensor

Speedometer cable

ECM
WIRING DIAGRAM
DI01B-23

A15714
A15715
DI-78
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located on the throttle
body and intake air bypassing the throttle valve is directed to
the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle-up and
provide feedback for the target idling speed.
DTC No.DTC Detection ConditionTrouble Area
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)

IAC valve is stuck or closed

Open or short in IAC valve circuit

Open or short A/C 1 signal circuit

Air intake (hose loose)
WIRING DIAGRAM
DI4LK-02

A15717
- DIAGNOSTICSENGINE
DI-81
1996 TERCEL (RM440U)
DTC P0510 Closed Throttle Position Switch Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI-33.
DTC No.DTC Detection ConditionTrouble Area
P0510Closed throttle position switch does not turn ON even once
when vehicle is driven (2 trip detection logic)
Open in closed throttle position switch circuit

Closed throttle position switch

ECM
HINT:
After confirming DTC P0510, use the TOYOTA hand-held tester to confirm the closed throttle position switch
signal from the CURRENT DATA.
Throttle ValveClosed Throttle Position Switch SignalMalfunction
Fully closedOFFOpen circuit
Fully openONShort circuit
WIRING DIAGRAM
Refer to DTC P0120 on page DI-33.
INSPECTION PROCEDURE
HINT:
If DTCs P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
TOYOTA hand-held tester:
1 Check for open in harness or ECM.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Disconnect the throttle position sensor connector.
(c) Connect the sensor wire harness terminals between ter-
minals 3 and 4.
(d) Turn the ignition switch ON.
CHECK:
Read thg CTP switch signal on the TOYOTA hand-held tester.
OK:
CTP switch signal: ON
OK Confirm good connection at sensor. If OK, re-
place throttle position sensor.
NG
DI95R-01

A15721
- DIAGNOSTICSENGINE
DI-85
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check spark plug and spark (See page IG-1).
NG Go to step 4.
OK
2 Check for open and short in harness and connector in IGF signal circuit between
ECM and igniter (See page IN-26).
NG Repair or replace harness or connector.

- DIAGNOSTICSENGINE
DI-89
1996 TERCEL (RM440U)
DTC P1335 Crankshaft Position Sensor Circuit
Malfunction (During engine running)
CIRCUIT DESCRIPTION
Refer to DTC P0335 on page DI-60.
DTC No.DTC Detection ConditionTrouble Area
P1335No crankshaft position sensor signal to ECM with engine
speed 1,000 rpm or more
Open or short in crankshaft position sensor circuit

Crankshaft position sensor

ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI-60.
DI1EH-14