1996 TOYOTA TERCEL ABS

- DIAGNOSTICSENGINE
DI-51
1996 TERCEL (RM440U)
4 Check injector injection (See page MF-19).
NG Replace injector.
OK
5 Check manifold absolute pressure sensor and engine coolant temp. sensor
(See page DI-20, DI-28).
NG Repair or replace.
OK
6 Check for spark and ignition (See page IG-1).
NG Repair or replace.
OK
Check and replace ECM (See page IN-26).

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

DI-56
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
OK
6 Check EGR system (See page EC-8).
NG Replace injector.
OK
7 Check manifold absolute pressure sensor and engine coolant temp. sensor (See
page DI-41 and DI-45).
NG Repair or replace.
OK
Check compression pressure (See page EM-3), valve clearance (See page EM-4) and valve tim-
ing (See page EM-17).

A15705
A15706
- DIAGNOSTICSENGINE
DI-65
1996 TERCEL (RM440U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temp. and reduce NOx
emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine load.
If even one of the following conditions is fulfilled, the VSV is
turned OFF by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut-off).

Before the engine is warmed up.

During deceleration (throttle valve closed).

Light engine load (amount of intake air very small).

Engine speed over 4,400 rpm.

Engine racing.
DTC No.DTC Detection ConditionTrouble Area
P0401
After the engine is warmed up, the intake manifold absolute
pressure is larger than the value calculated by the ECM while
the EGR system is ON.
(2 trip detection logic)

EGR valve stuck closed

Open or short in VSV circuit for EGR

Vacuum or EGR hose disconnected

Manifold absolute pressure sensor

EGR VSV open or close malfunction

ECM
WIRING DIAGRAM
DI95P-01

DI-68
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
4 Check EGR vacuum modulator (See page EC-7).
NG Repair or replace.
OK
5 Check EGR valve (See page EC-7).
NG Repair or replace.
OK
6 Check manifold absolute pressure sensor (See page DI-23).
NG Repair or replace.
OK
Check and replace ECM (See page IN-26).
OBD II scan tool (excluding TOYOTA hand-held tester):
1 Check connection of vacuum hose, EGR hose (See page EC-2).
NG Repair or replace.
OK

DI-70
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
5 Check EGR valve (See page EC-7).
NG Repair or replace.
OK
6 Check manifold absolute pressure sensor (See page DI-23).
NG Repair and replace.
OK
Check and replace ECM (See page IN-26).

- DIAGNOSTICSENGINE
DI-71
1996 TERCEL (RM440U)
DTC P0402 Exhaust Gas Recirculation Flow Excessive
Detected
CIRCUIT DESCRIPTION
Refer to DTC P0402 on page DI-65.
DTC No.DTC Detection ConditionTrouble Area
P0402
After the engine is warmed up, conditions (a) and (b) continue
(a) The intake manifold absolute pressure is larger than the
value calculated by the ECM while the EGR system is ON
(b) Misfiring is detected during idling
(2 trip detection logic)
EGR valve stuck open

Vacuum or EGR hose is connected to wrong post

Manifold absolute pressure sensor

ECM
INSPECTION PROCEDURE
HINT:

If DTC P0105 and/or P0106 and P0402 are output simultaneously, perform troubleshooting of DTC
P0105 first.

If DTC P0401 and P0402 are output simultaneously, perform troubleshooting of DTC P0402 first.
1 Check connection of vacuum hose, EGR hose (See page EC-2).
NG Repair or replace.
OK
2 Check EGR valve (See page EC-7).
NG Repair or replace.
OK
3 Check VSV for EGR (See page DI-65).
OK Go to step 5.
NG
DI95Q-01

DI-72
- DIAGNOSTICSENGINE
1996 TERCEL (RM440U)
4 Check operation of the for EGR (See page EC-7).
NG Replace VSV for EGR.
OK
Check for open and short in harness and con-
nector between engine room R/B and ECM
(See page IN-26).
5 Check EGR vacuum modulator (See page EC-7).
NG Repair or replace.
OK
6 Check manifold absolute pressure sensor (See page DI-23).
NG Repair or replace.
OK
Check and replace ECM (See page IN-26).