ignition TOYOTA TERCEL 1996 Service Workshop Manual

S00591
From Battery
Ignition Coil
Spark Plug
IGC1
IGC2
GND TA C IGT1
IGT2
To Tachometer ECM G
NE
No.1 Cylinder
No.4 Cylinder
Various
Sensor
IGF
No.2 Cylinder
No.3 Cylinder Camshaft
Position
Sensor
Crankshaft
Position
SensorIgniter
DI-84
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P1300 Ignition Circuit Malfunction
CIRCUIT DESCRIPTION
A DIS (Direct Ignition System) has been adopted. The DIS improves the ignition timing accuracy, reduces
high-voltage loss, and enhances the overall reliability of the ignition system by eliminating the distributor.
The DIS is a 2-cylinder simultaneous ignition system which ignites 2 cylinders simultaneously with one igni-
tion coil. In the 2-cylinder simultaneous ignition system, each of the 2 spark plugs is connected to the end
of the secondary winding. High voltage generated in the secondary winding is applied directly to the 2 spark
plugs. The sparks of the 2 spark plugs pass simultaneously from the center electrode to the ground elec-
trode.
The ECM determines ignition timing end outputs the ignition signals (IGT) for each cylinder. Based on IGT
signals, the igniter controls the primary ignition signals (IGC) for all ignition coils. At the same time, the igniter
also sends an ignition confirmation signal (IGF) as a fail-safe measure to the ECM.
DTC No.DTC Detection ConditionTrouble Area
P1300No IGF signal to ECM while engine is running

Open or short in IGF or IGT circuit from igniter to ECM

Igniter

ECM
DI3A0-04

A15722
A15723
DI-86
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
OK
3 Disconnect igniter connector and check voltage between terminal IGF of ECM
connector and body ground.
PREPARATION:
(a) Disconnect the igniter connector.
(b) Remove the lower finish panel.
(c) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal IGF of the ECM connec-
tor and the body ground.
OK:
Voltage: 4.5 - 5.5 V
OK Replace igniter.
NG
Check and replace ECM (See page IN-26).
4 Check for open and short in harness and connector in IGT1 and IGT2 signal cir-
cuits between ECM and igniter (See page IN-26).
NG Repair or replace harness or connector.
OK
5 Check voltage between terminals IGT1 and IGT2 of ECM connector and body
ground.
PREPARATION:
Remove the lower finish panel.
CHECK:
Measure the voltage between terminals IGT1 and IGT2 of the
ECM connector and the body ground when the engine is
cranked.
OK:
Voltage: More than 0.1 V and less than 4.5 V

P19902
IGT1 / IGF signal waveform
10 m sec./Division (Idling) IGT12V/
Division
IGF
A15725
A15726
- DIAGNOSTICSENGINE
DI-87
1996 TERCEL (RM440U)
Reference: INSPECTION USING OSCILLOSCOPE
During idling, check waveform between terminals IGT1 and E1
of ECM.
HINT:
The correct waveform are as shown.
IGT2 signal waveform is same as the IGT1 signal waveform.
NG Check and replace ECM (See page IN-26).
OK
6 Disconnect igniter connector and check voltage between terminals IGT1 and
IGT2 of ECM connector and body ground.
PREPARATION:
(a) Disconnect the igniter connector.
(b) Remove the lower finish panel.
CHECK:
Measure the voltage between terminals IGT1 and IGT2 of the
ECM connector and the body ground when the engine is
cranked.
OK:
Voltage: More than 0.1 V and less than 4.5 V
NG Check and replace ECM (See page IN-26).
OK
7 Check voltage between terminal 7 of igniter connector and body ground.
PREPARATION:
Disconnect the igniter connector.
CHECK:
Measure the voltage between terminal 7 of igniter connector
and the body ground, when ignition switch is turned to ON and
START position.
OK:
Voltage: 9 - 14 V
NG Check and repair igniter power source circuit.
OK

DI-88
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
8 Check for open and short in harness and connector between ignition switch and
ignition coil, ignition coil and igniter (See page IN-26).
NG Repair or replace harness or connector.
OK
9 Check ignition coil (See page IG-1).
NG Replace ignition coil.
OK
Replace igniter.

A15727
DI-90
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P1500 Starter Signal Circuit Malfunction
CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is therefore
necessary in order to achieve good startability. While the engine is being cranked, the battery voltage is ap-
plied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for
the starting injection control and after-start injection control.
DTC No.DTC Detection ConditionTrouble Area
P1500No starter signal to ECM

Open or short in starter signal circuit

Open or short in ignition switch or starter relay circuit

ECM
HINT:
In this circuit, diagnosis can only be made in the check mode.
WIRING DIAGRAM
DI95S-01

- DIAGNOSTICSENGINE
DI-91
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
HINT:
This diagnostic chart is based on the premise that the engine is cranked normally. If the engine is not
cranked, proceed to the problem symptoms table on page DI-19.
1 Connect TOYOTA hand-held tester, and check STA signal.
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.
CHECK:
Read the STA signal on the TOYOTA hand-held tester while the starter operates.
OK:
Ignition Switch PositionONSTART
STA SignalOFFON
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI-19).
NG
2 Check for open in harness and connector between ECM and starter relay (See
page IN-26).
NG Repair or replace or connector.
OK
Check and replace ECM.

A15728
A15729
DI-92
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P1600 ECM BATT Malfunction
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for
use by the DTC memory and air-fuel ratio adaptive control value memory, etc.
DTC No.DTC Detection ConditionTrouble Area
P1600Open in back up power source circuit
Open in back up power source circuit

ECM
HINT:
If DTC P1600 appear, the ECM does not store another DTC.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminal BATT of ECM connector and body ground.
PREPARATION:
Remove the lower finish panel.
CHECK:
Measure the voltage between terminal BATT of the ECM con-
nector and the body ground.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-26).
NG
DI01I-24

A15733
DI-96
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
NG Replace park/neutral position switch.
OK
2 Check voltage between terminal NSW of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal NSW of the ECM con-
nector and the body ground after the shift lever is moved to the
following positions.
Shift lever positionP or NL, 2, D or R
Voltage0 - 3 V9 - 14 V
OK Check and replace ECM (See page IN-26).
NG
Check for open and short in harness and con-
nector between ECM and park/neutral posi-
tion switch (See page IN-26).

A15734
- DIAGNOSTICSENGINE
DI-97
1996 TERCEL (RM440U)
ECM Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, battery positive voltage is applied to the coil, closing the contacts of
the EFI main relay and supplying power to the terminal +B of the ECM.
WIRING DIAGRAM
DI4LL-02

A15735
DI-98
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check voltage between terminals +B and E1 of ECM connector.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals +B and E1 of the ECM
connectors.
OK:
Voltage: 9 - 14 V
OK Proceed to next circuit inspection shown on
matrix chart (See page DI-19).
NG
2 Check for open in harness and connector between terminal E1 of ECM and body
ground (See page IN-26).
NG Repair or replace harness or connector.
OK
3 Check EFI main relay (Marking: EFI) (See page MF-38).
NG Replace EFI main relay.
OK
4 Check EFI fuse (See page DI-92, step 2).
NG Check for short in all harness and components
connected to EFI fuse.
OK