9. General Diagnostics Table
1. FOR ENGINE
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Problem parts
Mass air flow sensor
Engine coolant temperature sensor (*1)
Throttle position sensor
Crankshaft position sensor & Camshaft position sensor (*2)
Idle air control solenoid valve
Knock sensor
Purge control solenoid valve
EGR valve
Fuel injection parts (*3)
Ignition parts (*4)
Fuel pump and relay
A/C switch and A/C cut relay
Engine torque control signal circuitSymptom
1 Engine stalls during idling.
2 Rough idling
3 Engine does not return to idle.
4 Poor acceleration
5Engine stalls or engine sags or hesi-
tates at acceleration.
6 Surge
7 Spark knock
8 After burning in exhaust system
*1: The mark,, indicates the symptom occurring only in cold temperatures.
*2: For items with the mark,, ensure the secure installation of crankshaft position sensor and camshaft position sensor. Replacement is
not necessary.
*3: Check fuel injector, fuel pressure regulator and fuel filter.
*4: Check ignitor, ignition coil and spark plug.
NOTE:
Malfunction of parts other than the above is also possible. Refer to 1. Engine Trouble in General [K100] in Repair Section 2-3 or 2-3b of
the Service Manual.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
9. General Diagnostics Table
OBD0711
3) Disconnect fuel delivery hose from fuel filter, and con-
nect fuel pressure gauge.
G2M0348
4) Start the engine and idle while gear position is neutral.
5) Measure fuel pressure while disconnecting pressure
regulator vacuum hose from intake manifold.
: Is fuel pressure between 226 and 275 kPa
(2.3—2.8 kg/cm2,33—40 psi)?
: Go to next step 6).
: Repair the following items.
Fuel pressure too highClogged fuel return line or bent
hose
Fuel pressure too lowImproper fuel pump discharge
Clogged fuel supply line
6) After connecting pressure regulator vacuum hose, mea-
sure fuel pressure.
: Is fuel pressure between 157 and 206 kPa
(1.6—2.1 kg/cm2,23—30 psi)?
: Go to step10P4.
: Repair the following items.
Fuel pressure too highFaulty pressure regulator
Clogged fuel return line or bent
hose
Fuel pressure too lowFaulty pressure regulator
Improper fuel pump discharge
Clogged fuel supply line
WARNING:
Before removing fuel pressure gauge, release fuel
pressure.
NOTE:
If fuel pressure does not increase, squeeze fuel return
hose 2 to 3 times, then measure fuel pressure again.
If out of specification as measured at step 6), check or
replace pressure regulator and pressure regulator vacuum
hose.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code
