Page 188 of 1202

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 
     
        
        Page 226 of 1202

DI-52
- DIAGNOSTICSENGINE
1996 TERCEL   (RM440U)
DTC P0300 Random/Multiple  Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred. And
when the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detection ConditionTrouble Area
P0300Misfiring of random cylinders is detected during any particular
200 or 1,000 revolutionsIgnition system
Injector
P0301
P0302
For any particular 200 revolutions of the engine, misfiring is
detected which can cause catalyst overheating
(This causes MIL to blink)
Injector
Fuel line pressure
Compression pressure
Valve clearance not to specification
P0302
P0303
P0304For any particular 1,000 revolutions of the engine, misfiring is
detected which causes a deterioration in emissions
(2 trip detection logic)
Valve clearance not to s ecification
Valve timing
Manifold absolute pressure sensor
Engine coolant temp. sensor
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no Random Misfire code is
recorded, it indicates that the misfires were detected and recorded at different times.
DI39Y-04 
     
        
        Page 228 of 1202

P25779S00553A05593
DI-54
- DIAGNOSTICSENGINE
1996 TERCEL   (RM440U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Disconnect  the high-tension cord or ignition coil.
(b) Remove the spark plug.
CHECK:
(a) Check plug type.
(b) Check for carbon deposits on electrode.
(c) Check electrode gap.
OK:
(1) Twin ground electrodes type.
Recommended spark plug:
ND: K16TR11
NGK: BKR5EKB-11
(2) No large carbon deposit present.
Not wet with gasoline or oil.
(3) Electrode gap: 1.0 - 1.1 mm (0.039 - 0.043 in.)
PREPARATION:
(a) Install the spark plug to the high-tension cord or ignition
coil.
(b) Disconnect the injector connector.
(c) Ground the spark plug.
CHECK:
Check if spark occurs while engine is being cracked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, do not crank the engine for more than 5 -
10 seconds at a time.
OK:
Spark jumps across electrode gap.
NG  Replace or check ignition system (See page
IG-1).
OK 
     
        
        Page 229 of 1202
A15699
- DIAGNOSTICSENGINE
DI-55
1996 TERCEL   (RM440U)
2 Check voltage of ECM terminals for injector of failed cylinder.
PREPARATION:
(a) Remove the lower finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between applicable terminals of the ECM
connector  and the body ground.
OK:
Voltage: 9 - 14 V
OK Go to step 4.
NG
3 Check injector resistance of misfiring cylinder (See page MF-16).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN-26).
4 Check fuel pressure (See page MF-1).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page MF-5).
OK
5 Check injector injection (See page MF-16).
NG Replace injector. 
     
        
        Page 231 of 1202
A15700
- DIAGNOSTICSENGINE
DI-57
1996 TERCEL   (RM440U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
A knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelectric
element which generates a voltage when it becomes deformed, which occurs when the cylinder block vi-
brates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it.
DTC No.DTC Detection ConditionTrouble Area
P0325
No knock sensor 1 signal to ECM with engine speed 1,200 rpm
or more
(2 trip detection logic)Open or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fail-safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
DI012-20 
     
        
        Page 259 of 1202

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 
     
        
        Page 300 of 1202

- DIAGNOSTICSANTI-LOCK BRAKE SYSTEM
DI-125
1996 TERCEL   (RM440U)
DTC 21, 22, 23, 24 ABS Actuator Solenoid Circuit
CIRCUIT DESCRIPTION
This solenoid goes on when signals are received from the ECU and controls the pressure acting on the brake
cylinders, thus controlling the braking force.
DTC No.DTC Detecting ConditionTrouble Area
21
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: 
Battery positive voltage
2. Voltage or ABS ECU terminal AST: 
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SFR is 0 V or battery positive voltage
ABS actuator
Open or short in SFR circuit
ECU
22
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: 
Battery positive voltage
2. Voltage or ABS ECU terminal AST: 
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SFL is 0 V or battery positive voltage
ABS actuator
Open or short in SFL circuit
ECU
23
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: 
Battery positive voltage
2. Voltage or ABS ECU terminal AST: 
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SRR is 0 V or battery positive voltage
ABS actuator
Open or short in SRR circuit
ECU
24
Conditions 1 through 3 continue for 0.05 sec. or more:
1. ABS control (solenoid) relay terminal (SR) voltage: 
Battery positive voltage
2. Voltage or ABS ECU terminal AST: 
Battery positive voltage
3. When power transistor of ECU is ON, voltage of terminal
SRL is 0 V or battery positive voltage
ABS actuator
Open or short in SRL circuit
ECU
Fail safe function:
If trouble occurs in the actuator solenoid circuit, the ECU cuts off current to the ABS control (solenoid) relay
and prohibits ABS control.
DI4LW-03 
     
        
        Page 369 of 1202

DI-194
- DIAGNOSTICSPOWER DOOR LOCK CONTROL SYSTEM
1996 TERCEL   (RM440U)Terminals
SymbolsConditionSTD Value
B14A4DSWH EEngine hood courtesy switch ºONº.Below 1 WB14 e A4DSWH - EEngine hood courtesy switch ºOFFº.1 MW or higher
B15A4LSWD EDoor unlock detection switch  ºONº . (Driver's)Below 1 WB15 e A4LSWD - EDoor unlock detection switch ºOFFº. (Driver's)1 MW or higher
B16A4UL2 E
Door key lock and unlock switch ºUNLOCKº.
(Passenger's)Below 1 W
B16 e A4UL2 - EDoor key lock and unlock switch ºOFFº or ºLOCKº.
(Passenger's)1 MW or higher
B19A4DSWP EDoor courtesy switch ºONº. (Passenger's)Below 1 WB19 e A4DSWP - EDoor courtesy switch ºOFFº. (Passenger's)1 MW or higher
B20 e A4KSW - E
Key unlock warning switch ºONº.
(Key is inserted into key cylinder)Below 1 WB20 e A4KSW  E
Key unlock warning switch ºOFFº.1 MW or higher
B21A4LSWP EDoor unlock detection switch  ºONº . (Passenger's)Below 1 WB21 e A4LSWP - EDoor unlock detection switch ºOFFº. (Passenger's)1 MW or higher
B22A4L2 E
Door key lock and unlock switch ºLOCKº.
(Driver's)Below 1 W
B22 e A4L2 - EDoor key lock and unlock switch ºOFFº or ºUNLOCKº.
(Driver's)1 MW or higher
B23 e A4TAIL - ELight control switch ºOFFº.10 - 14 V
B24 e A4HORN - EHorn switch ºOFFº.10 - 14 V
B25 e A4SRLY - EIgnition switch is turned to ºSTº.
(when park / neutral position switch ºPº position)10 - 14 V