Isuzu 1999 RODEO Workshop Manual page 524

Malfunction Indicator Lamp
The instrument panel "CHECK ENGINE" Malfunction In-
dicator Lamp (MIL) illuminates by self diagnostic system
when the system checks the starting of engine, or senses
malfunctions.
Condition
"CHECK ENGINE" MIL does not
illuminate at the starting of engine illuminate at the starting of engine
"CHECK ENGINE" MIL illuminates,
and stays on
ENGINE MECHANICAL (X22SE 2.2L)
Possible cause
Bulb defective
MIL circuit open
Command signal circuit to operate
self diagnostic system shorted
Powertrain Control Module (PCM)
cable loosely connected,
disconnected or defective
PCM defective
Deterioration heated oxygen sensor
of internal element
Heated oxygen sensor connector
terminal improper contact
Heated oxygen sensor lead wire
shorted
Heated oxygen sensor circuit open
Deterioration engine
temperature sensor of
element
Engine coolant temperature sensor
connector terminal improper contact
Engine coolant temperature sensor
lead wire shorted
Engine coolant temperature sensor
circuit open
Throttle position sensor open or
shorted circuits
Deterioration of crankshaft position
sensor
Crankshaft position sensor circuit
open or shorted
Vehicle speed sensor circuit open
Manifold absolute pressure sensor
circuit open or shorted
Intake air temperature sensor circuit
open or shorted
Fuel injector circuit open or shorted
PCM driver transistor defective
Malfunctioning of PCM
(Random Access Memory) or ROM
(Read Only Memory)
Correction
Replace
Correct or replace
Correct or replace
Correct or replace
Replace
Replace
Reconnect properly
Correct
Correct or replace
coolant Replace
internal
Reconnect properly
Correct
Correct or replace
Correct or replace
Replace
Correct or replace
Correct or replace
Correct or replace
Correct or replace
Correct or replace
Replace PCM
RAM Replace PCM
6A–15