Workshop Manual

6A–18
ENGINE MECHANICAL (6VE1 3.5L)
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
Possible cause Correction
“CHECK ENGINE” MIL does not
illuminate at the starting of engine
Bulb defective Replace
ill
um
i
na
t
e a
t
th
e s
t
ar
ti
ng o
f
eng
i
ne
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