engine TOYOTA TERCEL 1996 Service Repair Manual

P25779S00553A05593
DI-54
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Disconnect the high-tension cord or ignition coil.
(b) Remove the spark plug.
CHECK:
(a) Check plug type.
(b) Check for carbon deposits on electrode.
(c) Check electrode gap.
OK:
(1) Twin ground electrodes type.
Recommended spark plug:
ND: K16TR11
NGK: BKR5EKB-11
(2) No large carbon deposit present.
Not wet with gasoline or oil.
(3) Electrode gap: 1.0 - 1.1 mm (0.039 - 0.043 in.)
PREPARATION:
(a) Install the spark plug to the high-tension cord or ignition
coil.
(b) Disconnect the injector connector.
(c) Ground the spark plug.
CHECK:
Check if spark occurs while engine is being cracked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, do not crank the engine for more than 5 -
10 seconds at a time.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG-1).
OK

A15699
- DIAGNOSTICSENGINE
DI-55
1996 TERCEL (RM440U)
2 Check voltage of ECM terminals for injector of failed cylinder.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between applicable terminals of the ECM
connector and the body ground.
OK:
Voltage: 9 - 14 V
OK Go to step 4.
NG
3 Check injector resistance of misfiring cylinder (See page MF-16).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN-26).
4 Check fuel pressure (See page MF-1).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page MF-5).
OK
5 Check injector injection (See page MF-16).
NG Replace injector.

DI-56
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
OK
6 Check EGR system (See page EC-8).
NG Replace injector.
OK
7 Check manifold absolute pressure sensor and engine coolant temp. sensor (See
page DI-41 and DI-45).
NG Repair or replace.
OK
Check compression pressure (See page EM-3), valve clearance (See page EM-4) and valve tim-
ing (See page EM-17).

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

A15701
DI-58
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check continuity between terminal KNK of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Disconnect the E7 connector of ECM.
CHECK:
Measure the resistance between terminal KNK of the ECM con-
nector and the body ground.
OK:
Resistance: 1 MW or higher
OK Go to step 3.
2 Check knock sensor (See page MF-50).
NG Replace knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knock
sensor (See page IN-26).
NG Repair or replace harness or connector.
OK
4 Does malfunction disappear when a good knock sensor is installed?
YES Replace knock sensor.
NO
Check and replace ECM (See page IN-26).

FI6510FI6642A07134
Knock signal waveform
0.5V/
Division
0V
0V5 m sec./Division
100 m sec./Division 0.5V/
Division
- DIAGNOSTICSENGINE
DI-59
1996 TERCEL (RM440U)
Reference: INSPECTION USING OSCILLOSCOPE

With the engine racing (4,000 rpm) measure between ter-
minal KNK of ECM and body ground.
HINT:
The correct waveform is as shown.

Spread the time on the horizontal axis, and confirm that
period of the wave is 123 m sec.
(Normal mode vibration frequency of knock sensor: 8.1
KHz.)
HINT:
If normal mode vibration frequency is not 8.1 KHz, the sensor
is malfunctioning.

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

A01991A01992A02359
G, NE signal waveforms
5V/
Division
G
NE
20 m sec./Division (Idling)
5V/
Division
G
NE
10 m sec./Division (Idling)
- DIAGNOSTICSENGINE
DI-61
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor (See page IG-1).
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G2, NE and
NE- of ECM
HINT:
The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and crank-
shaft position sensor (See page IN-26).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and teeth of signal plate.
NG Tighten the sensor.
Replace signal plate.
OK

DI-62
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
Check and replace ECM (See page IN-26).

- 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