1996 TOYOTA TERCEL wiring

A10940
ECM
E7
E7 L-B
BR5V
R
E1 E2 THA
2
1 Intake Air Temp. Sensor
15
16
- DIAGNOSTICSENGINE
DI-25
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0105, P0106, P0110, P0115, P0120 are output simultaneously, E2 (sensor ground) may be open.
1 Connect OBD II scan tool or TOYOTA hand-held tester, and read value of intake
air temperature.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(c) Turn the ignition switch ON and OBD II scan tool or TOYOTA hand-held tester main switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYOTA hand-held tester.
OK:
Same value as the actual intake air temperature.
HINT:

If there is open circuit, OBD II scan tool or TOYOTA hand-held tester indicates -40°C (-40°F).

If there is short circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG -40°C (-40°F) ... Go to step 2.
140°C (284°F) or more ... Go to step 4.
OK
Check for intermittent problems
(See page DI-3).

A10940
ECM
E7
E7 G-B
BR5V
E1 E2 THW
2
1 Engine Coolant Temp. Sensor
3
16 DI-28
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temperature sensor changes the resistance value according to the
engine coolant temperature. The structure of the sensor and connection to the ECM is the same as in the
intake air temp. circuit malfunction shown on page DI-24.
If the ECM detects the DTC P0115, it operates the fail-safe function in which the engine coolant temp. is
assumed to be 80°C (176°F).
DTC No.DTC Detection ConditionTrouble Area
P0115Open or short in engine coolant temp. sensor circuit

Open or short in engine coolant temp. sensor circuit

Engine coolant temp. sensor

ECM
HINT:
After confirming DTC P0115, use the OBD II scan tool or TOYOTA hand-held tester to confirm the engine
coolant temperature from the CURRENT DATA.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
WIRING DIAGRAM
DI1E6-08

A15689
FI7052
DI-34
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0105, P0110, P0120 are output simultaneously, E2 (sensor ground) may be open.
1 Connect OBD II scan tool or TOYOTA hand-held tester and read throttle valve
opening percentage.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand-held tes-
ter to the DLC3.
(c) Turn the ignition switch ON and OBD II scan tool or TOY-
OTA hand-held tester main switch ON.
CHECK:
Read the throttle valve opening percentage.
OK:
Throttle valveThrottle valve opening
position expressed as percentage
Fully openApprox. 70 %
Fully closedApprox. 10 %
OK Check for intermittent problems
(See page DI-3).
NG

A15693
- DIAGNOSTICSENGINE
DI-39
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect OBD II scan tool or TOYOTA hand-held tester and read value for volt-
age output of heated oxygen sensor.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(c) Warm up the engine to the normal operating temperature.
CHECK:
Read the voltage output of the heated oxygen sensor (bank 1 sensor 1) when the engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 times using accelerator pedal.
OK:
Heated oxygen sensor output a RICH signal (0.45 V or more) at least once.
OK Check and replace ECM (See page IN-26).
NG
2 Check for open and short in harness and connector between ECM and oxygen
sensor (See page IN-26).
NG Repair or replace harness or connector.

FI7130
Vehicle Speed
50 - 65 km/h
(31 - 40 mph)
Idling
IG SW OFF
1 - 3 min.
1 min.
Time
(1) (2)
(3)(4)
(5)
- DIAGNOSTICSENGINE
DI-41
1996 TERCEL (RM440U)
DTC P0130 Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-38.
DTC No.DTC Detection ConditionTrouble Area
P0130
Voltage output of oxygen sensor remains at 0.4 V or
more, or 0.55 V or less, during idling after the engine is
warmed up (2 trip detection logic)
Oxygen sensor

Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
The oxygen sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan
tool or TOYOTA hand-held tester.
WIRING DIAGRAM
Refer to page DI-38.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand-held tester to the DLC3.
(2) Switch the TOYOTA hand-held tester from normal mode to check mode (See page DI-3).
(3) Start the engine and warm it up with all accessory switches OFF.
(4) Drive the vehicle at 50 - 65 km/h (31 - 40 mph) for 1 - 3 minutes to warm up the oxygen sensor.
(5) Idle the engine for 1 minute.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a TOYOTA hand-held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI1EB-08

- DIAGNOSTICSENGINE
DI-45
1996 TERCEL (RM440U)
DTC P0136 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-38.
DTC No.DTC Detection ConditionTrouble Area
P0136
Voltage output of the heated oxygen sensor (bank 1 sensor 2)
remains at 0.4 V or more, or 0.5 V or less when the vehicle is
driven at 50 km/h (31 mph) or more after the engine is warmed
up
(2 trip detection logic).

Heated oxygen sensor
HINT:
Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to page DI-38.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart.
NO
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN-26).
NG Repair or replace harness or connector.
OK
DI00Y-21

A15695
- DIAGNOSTICSENGINE
DI-47
1996 TERCEL (RM440U)
DTC P0135 Heated Oxygen Sensor Heated Circuit
Malfunction (Bank 1 Sensor 1)
DTC P0141 Heated Oxygen Sensor Heated Circuit
Malfunction (Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-38.
DTC No.DTC Detection ConditionTrouble Area
P0135
When the heater operates, heater current exceeds 2 A
(2 trip detection logic)
Open or short in heater circuit of heated oxygen sensor
Htd htP0135
P0141Heater current of 0.25 A or less when the heater
operates (2 trip detection logic)
Heated oxygen sensor heater

ECM
WIRING DIAGRAM
Refer to page DI-38.
INSPECTION PROCEDURE
1 Check voltage between terminal HT1, HT2 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 HT1, HT2 of the ECM
connector and the body ground.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-26).
NG
2 Check resistance of heated oxygen sensor heater (See page MF-53).
NG Replace heated oxygen sensor.
OK
DI1ED-1 1

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.