1996 TOYOTA TERCEL ECM

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.

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

- 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

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

P20272A04988
Engine Room R/B
EFI Fuse
- DIAGNOSTICSENGINE
DI-93
1996 TERCEL (RM440U)
2 Check EFI fuse.
PREPARATION:
Remove the EFI fuse from the engine room R/B.
CHECK:
Check the continuity of the EFI fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to EFI fuse.
OK
Check and repair harness or connector
between battery, EFI fuse and ECM