1996 TOYOTA TERCEL ABS

- DIAGNOSTICSENGINE
DI-1 1
1996 TERCEL (RM440U)
Proceed to matrix chart of problem symp-
toms on page DI-19.
7. ENGINE OPERATING CONDITION
NOTICE:
The values given below for ºNormal Conditionº are representative values, so a vehicle may still be
normal even if its value from those listed here. So do not decide whether a part is faulty or not solely
according to the ºNormal Conditionº here.
CARB mandated signals:
TOYOTA hand-held tester displayMeasurement ItemNormal Condition*
FUEL SYS #1
Fuel System Bank 1
OPEN: Air-fuel ratio feedback stopped
CLOSED: Air-fuel ratio feedback operating
Idling after warming up: CLOSED
CALC LOAD
Calculator Load:
Current intake air volume as a proportion of max.
intake air volumeIdling: 19.7 - 47.4 %
Racing without load (2,500rpm): 18.8 - 46.4 %
COOLANT TEMP.Engine Coolant Temp. Sensor ValueAfter warming up: 80 - 95°C (176 - 203°F)
SHORT FT #1Short-term Fuel Trim Bank 10 ± 20%
LONG FT #1Long-term Fuel Trim Bank 10 ± 20%
ENGINE SPDEngine SpeedIdling: 700 - 800 rpm
VEHICLE SPDVehicle SpeedVehicle Stopped: 0 km/h (0 mph)
IGN ADVANCEIgnition Advance:
Ignition Timing of Cylinder No. 1Idling: BTDC 7 - 14°
INTAKE AIRIntake Air Temp. Sensor ValueEquivalent to Ambient Temp.
MAPAbsolute Pressure Inside Intake Manifold
Idling: 20 - 48 kPa
Racing without load (2,500 rpm):
19 - 47 kPa
THROTTLE POS
Voltage Output of Throttle Position Sensor
Calculated as a percentage:
0 V "0%, 5 V "100%Throttle Fully Closed: 6 - 16 %
Throttle Fully Open: 64 - 98 %
O2S B1, S1Voltage Output of Heated Oxygen Sensor
Bank 1, Sensor 1Idling: 0.1 - 0.9 V
O2FT B1, S1Oxygen Sensor Fuel Trim Bank 1, Sensor 1
(Same as SHORT FT #1)0 ± 20 %
O2S B1, S2Voltage Output of Oxygen Sensor
Bank 1, Sensor 2Driving at 50 km/h (31 mph): 0.1 - 0.9 V
*: If no conditions are specifically stated for ºldlingº, it means the shift lever is at N or P position, the A/C switch
is OFF and all accessory switches are OFF.

DI4LF-02
- DIAGNOSTICSENGINE
DI-13
1996 TERCEL (RM440U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, check the circuit for that code listed
in the table below, for details of each code, turn to the page referred to under the ''See page '' for the respec-
tive ''DTC No.'' in the DTC chart.
SAE Controlled:
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P0105
(DI-20)
Manifold Absolute
Pressure/Barometric
Pressure Circuit
MalfunctionOpen or short in manifold absolute pressure sensor circuit
Manifold absolute pressure sensor
ECM

P0106
(DI-23)
Manifold Absolute
Pressure/Barometric
Pressure Circuit
Range/Performance Problem
Manifold absolute pressure sensor
P0110
(DI-24)Intake Air Temp. Circuit
MalfunctionOpen or short in intake air temp. sensor circuit
Intake air temp. sensor
ECM

P0115
(DI-28)Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM

P0116
(DI-32)Engine Coolant Temp. Circuit
Range/Performance ProblemEngine coolant temp. sensor
Cooling system
P0120
(DI-33)Throttle/Pedal Position
Sensor/Switch ºAº Circuit
MalfunctionOpen or short in throttle position sensor circuit
Throttle position sensor
ECM

P0121
(DI-37)Throttle/Pedal Position
Sensor/Switch ºAº Circuit
Range/Performance Problem
Throttle position sensor
P0125
(DI-38)Insufficient Coolant Temp. for
Closed Loop Fuel ControlOpen or short in oxygen sensor circuit
Oxygen sensor
P0130
(DI-41)Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
P0133
(DI-44)Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)
Oxygen sensor
P0136
(DI-45)Heated Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Heated oxygen sensor
P0141
(DI-47) Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 2)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM

*: 


MIL lights up

DI-14
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)DTC No.
(See Page)
Detection ItemTrouble AreaMIL*Memory
P0171
(DI-49)System too Lean
(Fuel Trim)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor

P0172
(DI-49)System too Rich
(Fuel Trim)
Fuel line pressure
Injector blockage, leak
Oxygen sensor malfunction
Manifold absolute pressure sensor
Engine coolant temp. sensor

P0300
(DI-52)Random/Multiple Cylinder
Misfire DetectedIgnition system
Injector
FlliP0301
P0302
P0303
P0304
(DI-52)Misfire Detected
- Cylinder 1
- Cylinder 2
- Cylinder 3
- Cylinder 4Fuel line pressure
Compression pressure
Valve clearance not to specification
Valve timing
Manifold absolute pressure sensor
Engine coolant temp. sensor

P0325
(DI-57)Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM

P0335
(DI-60)Crankshaft Position Sensor
Circuit ºAº Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM

P0340
(DI-63)Camshaft Position Sensor
Circuit Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Starter
ECM

P0420
(DI-73)Catalyst System Efficiency
Below ThresholdThree-way catalytic converter
Open or short in (heated) oxygen sensor circuit
(Heated) oxygen sensor

P0500
(DI-76)Vehicle Speed Sensor
Malfunction
Open or short in vehicle speed sensor circuit
Vehicle speed sensor
Speedometer cable
ECM

P0505
(DI-78)Idle Control System
Malfunction
IAC valve is stuck or closed
Open or short in IAC valve circuit
Open or short in AC1 switch circuit
Air intake (hose loose)

*: 


MIL lights up

DI1E3-06
P01242
750
450
100 (3.96)
3.6
1.2
(840) 2.4
150
60 20
(112)kPa mmHg
Manifold Absolute Pressure
Output Voltage
V DI-20
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
CIRCUIT INSPECTION
DTC P0105 Manifold Absolute Pressure/Barometric
Pressure Circuit Malfunction
CIRCUIT DESCRIPTION
By a built-in sensor unit, the manifold absolute pressure sensor
detects the intake manifold pressure as a voltage. The ECM
then determines the basic injection duration and basic injection
advance angle based on this voltage. Since the manifold abso-
lute pressure sensor does not use the atmospheric pressure as
a criterion, but senses the absolute pressure inside the intake
manifold (the pressure in proportion to the present absolute
vacuum 0), it is not influenced by fluctuations in the atmospheric
pressure due to high altitude and other factors. This permits it
to control the air-fuel ratio at the proper lever under all condi-
tions.
DTC No.DTC Detection ConditionTrouble Area
P0105Open or short manifold absolute pressure sensor circuit

Open or short in manifold absolute pressure sensor circuit

Manifold absolute pressure sensor

ECM
If the ECM detects DTC P0105, it operates the fail-safe function, keeping the ignition timing and injection
volume constant and making it possible to drive the vehicle.
HINT:
After confirming DTC P0105, use the OBDII scan tool or TOYOTA hand-held tester to confirm the manifold
absolute pressure from the CURRENT DATA.
Manifold absolute pressureTrouble Area
0 kPaPIM circuit short
130 kPa or more
VC circuit open or short
PIM circuit open
E2 circuit open

A15677
- DIAGNOSTICSENGINE
DI-21
1996 TERCEL (RM440U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTC P0105, 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 man-
ifold absolute pressure.
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 OBDII scan tool or TOYOTA hand-held tester main switch ON.
CHECK:
Read value of manifold absolute pressure on the OBD II scan tool or TOYOTA hand-held tester.
OK:
Same value as the atmospheric pressure
OK Check for intermittent problems (See page
DI-3).
NG

A15678
A15679
DI-22
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
2 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals VC and E2 of the ECM
connector.
OK:
Voltage: 4.5 - 5.5 V
NG Check and replace ECM (See page IN-26).
OK
3 Check voltage between terminals PIM and E2 of ECM connector.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals PIM and E2 of ECM con-
nector.
OK:
Voltage: 3.3 - 3.9 V
OK Check and replace ECM (See page IN-26).
NG
4 Check for open and short in harness and connector between manifold absolute
pressure sensor and ECM.
NG Repair or replace harness or connector.
OK
Replace manifold absolute pressure sensor.

- DIAGNOSTICSENGINE
DI-23
1996 TERCEL (RM440U)
DTC P0106 Manifold Absolute Pressure/Barometric
Presure Circuit Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0105 on page DI-20.
DTC No.DTC Detection ConditionTrouble Area
P0106
Conditions (a) and (b) continue with engine speed
400 - 1,000 rpm:
(2 trip detection logic)
(a) Closed throttle position switch: ON
(b) Manifold absolute pressure sensor output > 3.0 V

Manifold absolute pressure sensor
WIRING DIAGRAM
Refer to DTC P0105 on page DI-20.
INSPECTION PROCEDURE
HINT:
If DTC P0105 and P0106 are output simultaneously, manifold absolute pressure sensor circuit may be open.
Perform troubleshooting of DTC P0105 first.
1 Are there any other codes (besides DTC P0106) being output?
YES Go to relevant DTC chart.
NO
2 Check manifold absolute pressure sensor (See page MF-48).
NG Replace manifold absolute pressure sensor.
OK
Check vacuum line for manifold absolute
pressure sensor for blockage.
DI1E4-05

- DIAGNOSTICSENGINE
DI-49
1996 TERCEL (RM440U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
ºFuelº trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short-term fuel trim and long-term fuel trim.
ºShort-term fuel trimº is the short-term fuel compensation used to maintain the air-fuel ratio at its ideal
theoretical value. The signal from the oxygen sensor indicates whether the air-fuel ratio is RICH or LEAN
compared to the ideal theoretical value, triggering a reduction in fuel volume if the air-fuel ratio is rich, and
an increase in fuel volume if it is lean.
ºLong-term fuel trimº is overall fuel compensation carried out long-term to compensate for continual devi-
ation of the short-term fuel trim form the central value due to individual engine differences, wear over time
and changes in the usage environment.
If both the short-term fuel trim and long-term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detection ConditionTrouble Area
P0171
When the air-fuel ratio feedback is stable after engine warming
up, the fuel trim is considerably in error on the RICH side
(2 trip detection logic)

Air intake (hose loose)

Fuel line pressure

Injector blockage

Heated oxygen sensor malfunction

Manifold absolute pressure sensor

Engine coolant temp. sensor
P0172
When the air-fuel ratio feedback is stable after engine warming
up, the fuel trim is considerably in error on the LEAN side.
(2 trip detection logic)

Fuel line pressure

Injector blockage, leak

Heated oxygen sensor malfunction

Manifold absolute pressure sensor

Engine coolant temp. sensor
HINT:

When DTC P0171 is recorded, the actual air-fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air-fuel ratio is on the RICH side.

If the total of the short-term fuel trim value and long-term fuel trim value is within + 25 %, the system
is functioning normally.

If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.
DI052-09