Temperature TOYOTA TERCEL 1996 Service User Guide

DI4LD-02
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Date Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
km
miles
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Driveaability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after-fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Datas Problem
Occurred
Problem Frequency
Condition When
Problem Occurs
Weather
Engine Operation
Engine Temp. Place Outdoor
TemperatureConstant
Sometimes ( times per day/month)Once only
Other
Fine
CloudyRainySnowyVarious/Other
Hot
Warm CoolCold (approx. °F/ °C)
Highway
SuburbsInner CityUphillDownhill
Rough road
Other
Cold
Warming upAfter Warming upAny temp.Other
Starting
Just after starting ( min.)IdlingRacing
Driving
Constant speedAccelerationDeceleration
A/C switch ON/OFF
Other
Condition of MILRemains on Sometimes light up Does not light up
NormalMalfunction code(s) (code )
Freeze frame data ( )
NormalMalfunction code(s) (code )
Freeze frame data ( )
Normal mode
(Pre-check)
Check Mode DTC InspectionInspector's
Name
DI-2
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
CUSTOMER PROBLEM ANALYSIS CHECK

N09214
DTC3 DI-4
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)

The diagnosis system operates in normal mode
during normal vehicle use. It also has a check mode
for technicians to simulate malfunction symptoms
and troubleshoot. Most DTC use 2 trip detection
logic* to prevent erroneous detection, and ensure
thorough malfunction detection. By switching the
ECM to check mode when troubleshooting, the
technician can cause the MIL to light up for a mal-
function that is only detected once or momentarily
(TOYOTA hand-held tester only) (See page
DI-3).

*2 trip detection logic:
When a logic malfunction is first detected, the mal-
function is temporarily stored in the ECM memory.
If the same malfunction is detected again during the
second drive test, this second detection causes the
MIL to light up.

The 2 trip repeats the same mode a 2nd time (How-
ever, the IG switch must be turned OFF between the
1st trip and 2nd trip.).

Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTC P0300 - P0304) or fuel trim
malfunction (DTC P0171, P0172) or other malfunc-
tion (first malfunction only), is detected, as freeze
frame data records the engine conditions (fuel sys-
tem, calculator load, engine coolant temperature,
fuel trim,engine speed, vehicle speed, etc.) when
the malfunction is detected, when troubleshooting
it is useful for determining whether the vehicle was
running or stopped, the engine warmed up or not,
the air-fuel ratio lean or rich, etc. at the time of the
malfunction.
Priorities for troubleshooting:
If troubleshooting priorities for multiple DTC are given in the ap-
plicable DTC chart, these should be followed.
If no instructions are given troubleshoot DTC according to the
following priorities.
(1) DTC other than fuel trim malfunction (DTC P0171,
P0172) and misfire (DTC P0300 - P0304).
(2) Fuel trim malfunction (DTC P0171, P0172).
(3) Misfire (DTC P0300 - P0304).
(b) Check the DLC3.
The vehicle's ECM uses ISO 9141-2 for communication.
The terminal arrangement of DLC3 complies with SAE
J1962 and matches the ISO 9141-2 format.

MA0659
Outside
Inside
DI-8
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
YES
2 Is engine cranked ?
NO Proceed to ST-13, ST-28, ST-31 and continue
to troubleshoot.
YES
3 Does engine start ?
NO Go to step 7.
YES
4 Check air filter.
PREPARATION:
Remove the air filter.
CHECK:
Visual check that the air cleaner element is not excessively dirty
or oily.
HINT:
If necessary, clean the filter with compressed air. First blow from
inside thoroughly, then blow from outside of filter.
NG Repair or replace.
OK
5 Check engine idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ºNº position.

P25914P25915A07081
TE1
E1 SST
DLC1
- DIAGNOSTICSENGINE
DI-9
1996 TERCEL (RM440U)
(e) Remove the fuse cover on the instrument panel.
(f) Connect the OBD II scan tool or TOYOTA hand-held tester to DLC3 on the vehicle.
CHECK:
Use CURRENT DATA to check the engine idle speed.
OK:
Idle speed: 700 - 800 rpm
NG Proceed to matrix chart of problem symptoms
on page DI-19.
OK
6 Check ignition timing.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Shift transmission into ºNº position.
(c) Keep the engine speed at idle.
(d) Using SST, connect terminals TE1 and E1 of DLC1.
SST 09843-18020
(e) Using a timing light, connect the tester to No.1 high-ten-
sion cord.
CHECK:
Check ignition timing.
OK:
Ignition timing: 10° BTDC at idle
NG Proceed to page IG-1 and continue to trouble-
shoot.
OK
Proceed to matrix chart of problem symp-
toms on page DI-19.

FI4741 (-4) 0.1 0.2
0 -20 0.3 0.51 2 35 10 20 30
20 40 60 80 100
(32) (68) (104) (140) (212)(176)
Resistance kW
Acceptable
Temp.°C (°F) (fig.1)
DI-24
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into the air cleaner
cap and senses the intake air temperature. A thermistor built in
the sensor changes the resistance value according to the in-
take air temperature. The lower the intake air temperature, the
greater the thermistor resistance value, and the higher the in-
take air temperature, the lower the thermistor resistance value
(See Fig. 1). The intake air temperature sensor is connected to
the ECM (See next page). The 5 V power source voltage in the
ECM is applied to the intake air temperature sensor from the ter-
minal THA via a resistor R. That is, the resistor R and the intake
air temp. sensor are connected in series. When the resistance
value of the intake air temperature sensor changes in accor-
dance with changes in the intake air temperature, the potential
at terminal THA also changes. Based on this signal, the ECM
increases the fuel injection volume to improve driveability dur-
ing cold engine operation.
If the ECM detects the DTC ºP0110º, it operates the fail-safe
function in which the intake air temperature is assumed to be
20° (68°F).
Reference
Intake air temp.
°C (°F)Resistance
(kW)Voltage
(V)
-20 (-4)16.24.3
0 (32)5.93.4
20 (68)2.52.4
40 (104)1.11.5
60 (140)0.60.9
80 (176)0.30.5
100 (212)0.20.3
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit

Open or short in intake air temp. sensor circuit

Intake air temp. sensor

ECM
HINT:
After confirming DTC P0110, use the OBD II scan tool or TOYOTA hand-held tester to confirm the intake
air temperature from the CURRENT DATA.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
DI1E5-08

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).

A15681
A15682
DI-26
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the intake air temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand-held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Confirm good connection at sensor.
If OK, replace intake air temp. sensor.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the lower finish panel.
(b) Connect terminals THA and E2 of ECM connector togeth-
er.
HINT:
Intake air temperature sensor connector is disconnected. Be-
fore checking, do a visual and contact pressure check for the
ECM connector (See page IN-26).
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand-held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Open in harness between terminal E2 or termi-
nal THA, repair or replace harness.
NG
Confirm good connection at ECM.
If OK, replace ECM.

A15742
A15683
- DIAGNOSTICSENGINE
DI-27
1996 TERCEL (RM440U)
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the intake air temp. sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand-held tester.
OK:
Temperature value: -40°C (-40°F)
OK Replace intake air temp. sensor.
NG
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the lower finish panel.
(b) Disconnect the E7 connector of ECM.
HINT:
Intake air temperature sensor connector is disconnected.
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand-held tester.
OK:
Temperature value: -40°C (-40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN-26).

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

A15685
- DIAGNOSTICSENGINE
DI-29
1996 TERCEL (RM440U)
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 engine
coolant 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 temperature value on the OBD II scan tool or TOYOTA hand-held tester.
OK:
Same value as the actual engine coolant 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).
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand-held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Confirm good connection at sensor. If OK, re-
place engine coolant temp. sensor
NG