1996 TOYOTA TERCEL ignition

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 revolutions
Ignition 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

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

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.

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

P20769
Vehicle Speed
70 - 90 km/h
(43 - 56 mph)
Idling
IG SW OFF(a)(b)(c)
(d)
(e)(f)
(g)
Warm up 3 - 5 min. 2 min. 3 - 5 min. 2 min.
Time DI-66
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
SYSTEM CHECK DRIVING PATTERN
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Start the engine and warm it up with all accessories switched OFF.
(c) Run the vehicle at 70 - 90 km/h (43 - 56 mph) for 3 minutes or more.
(d) Idle the engine for about 2 minutes.
(e) Stop at safe place and turn the ignition switch OFF.
(f) Start the engine and do steps (c) and (d) again.
(g) Check the READINESS TESTS mode on the OBD II scan tool or TOYOTA hand-held tester. If COMPL
is displayed and the MIL does not light up, the system is normal. If INCMPL is displayed and the MIL
does not light up, run the vehicle again and check it.
HINT:
INCMPL is displayed when either condition (h) or (i) exists.
(h) The system check is incomplete.
(i) There is a malfunction in the system.
If there is a malfunction in the system, the MIL will light up after steps (b) to (f) above are done.
INSPECTION PROCEDURE
HINT:

If DTC P0105 and/or P0106 and P0401 are output simultaneously, perform troubleshooting of DTC
ºP0105º first.

If DTC P0401 and P0402 are output simultaneously, perform troubleshooting of DTC P0402 first.

A15709
- DIAGNOSTICSENGINE
DI-69
1996 TERCEL (RM440U)
2 Check VSV for EGR.
PREPARATION:
(a) Turn up the floor mat on the passenger side.
(b) Remove the 2 bolts for ECM.
(c) Disconnect the ºE5º or ºE8º connector of ECM.
(d) Turn the ignition switch ON.
CHECK:
Check VSV function
(1) Connect terminal EGR of the ECM connector and
the body ground (ON).
(2) Disconnect terminal EGR of the ECM connector
and the body ground (OFF).
OK:
(1) VSV is ON:
Air from pipe E is flowing out through pipe F.
(2) VSV is OFF:
Air from pipe E is flowing out through the air filter.
OK Go to step 4.
NG
3 Check operation of VSV for EGR (See page DI-65, step 3).
NG Replace VSV for EGR.
OK
Check for open and short in harness and
connector between J/B No.2 and ECM
(See page IN-26).
4 Check EGR vacuum modulator (See page EC-7).
NG Repair or replace.
OK

A15713
AT7809
4.5 - 5.5 V
0
Turn the wheel
- DIAGNOSTICSENGINE
DI-77
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit. See combination
meter troubleshooting.
OK
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Shift the shift lever to neutral.
(c) Jack up one of the front wheels.
(d) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal SPD of the ECM con-
nector and the body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector be-
tween combination meter and ECM.
OK
Check and replace ECM (See page IN-26).

A15716
- DIAGNOSTICSENGINE
DI-79
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Check air induction system (See page MF-1).
NG Repair or replace.
OK
2 Check A/C signal circuit (See page AC-66).
NG Repair or replace.
OK
3 Check voltage between terminals RSO, RSC of ECM connector and body ground.
PREPARATION:
(a) Remove the lower finish panel.
(b) Disconnect the E7connector of ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal RSO and RSC of the
ECM connector and the body ground.
OK:
Voltage: 9 - 14 V
OK Go to step 5.
NG
4 Check IAC valve (See page MF-33).
NG Replace IAC valve.
OK