Isuzu Trooper (1998-2002 year). Manual - part 372
6A–18
ENGINE MECHANICAL (6VE1 3.5L)
Malfunction Indicator Lamp
The instrument panel “CHECK ENGINE” Malfunction
Indicator Lamp (MIL) illuminates by self diagnostic
system when the system checks the starting of engine, or
senses malfunctions.
Condition
Possible cause
Correction
“CHECK ENGINE” MIL does not
illuminate at the starting of engine
Bulb defective
Replace
illuminate at the starting of engine
MIL circuit open
Correct or replace
Command signal circuit to operate
self diagnostic system shorted
Correct or replace
Powertrain Control Module (PCM)
cable loosely connected,
disconnected or defective
Correct or replace
PCM defective
Replace
“CHECK ENGINE” MIL illuminates,
and stays on
Deterioration of heated oxygen
sensor internal element
Replace
Heated oxygen sensor connector
terminal improper contact
Reconnect properly
Heated oxygen sensor lead wire
shorted
Correct
Heated oxygen sensor circuit open
Correct or replace
Deterioration of engine coolant
temperature sensor internal element
Replace
Engine coolant temperature sensor
connector terminal improper contact
Reconnect properly
Engine coolant temperature sensor
lead wire shorted
Correct
Engine coolant temperature sensor
circuit open
Correct or replace
Throttle position sensor open or
shorted circuits
Correct or replace
Deterioration of crankshaft position
sensor
Replace
Crankshaft position sensor circuit
open or shorted
Correct or replace
Vehicle speed sensor circuit open
Correct or replace
Manifold absolute pressure sensor
circuit open or shorted
Correct or replace
Intake air temperature sensor circuit
open or shorted
Correct or replace
Fuel injector circuit open or shorted
Correct or replace
PCM driver transistor defective
Replace PCM
Malfunctioning of PCM RAM
(Random Access Memory) or ROM
(Read Only Memory)
Replace PCM