FAILURE DIAGNOSTIC LIST
1-226
TNV DI Service Manual
Failure Diagnostic List
Electr
ic
sy
stem
Fuse meltdown, disconnection
c
c
c
c
c
Inspection and replacement of fuse
Repair or replacement of harness
For harness inspection method, see
"Failure Diagnosis" (on page 1-1).
Starter fault
c
c
Repair or replacement of starter
See "Starter Motor" (on page 11-10).
Alternator fault
c
c
Repair or replacement of alternator
See "Removal of Alternator" (on page 12-
12).
Wiring disconnection
c
c
c
c
c
c
c
c
Repair or replacement of harness
disconnection
Wiring short-circuit (insulator broken),
electric power load of added device too
big
c
c
Inspection, repair or replacement of
harnesses
Review of added devices
Battery voltage descent
c
c
-
Inspection and charging of battery
See "Check Battery" (on page 5-26).
Key switch fault, disconnection
c
c
c
Repair or replacement of harness
Key switch replacement
For harness inspection method, see
"Failure Diagnosis" (on page 1-1).
Instantaneous interruption of key
switch
c
c
Key switch replacement
Failure, disconnection, short-circuit of
starter relay
c
Repair or replacement of harness
Replacement of starter relay
For harness inspection method, see
"Failure Diagnosis" (on page 1-1).
Main relay fault
(Error other than contact sticking that
ECU can’t detect)
c
c
Repair or replacement of harness
Replacement of main relay
For harness inspection method, see
"Failure Diagnosis" (on page 1-1).
Actuator relay fault
(Error of contact that ECU can’t detect)
c
c
c
Replacement of actuator relay
The start assist relay may be faulty.
(Error of contact that ECU can’t detect)
c
c
c
c
Replacement of start assist relay
Accelerator sensor signal error
(Error at which level ECU can’t detect)
c
c
c
c
Repair or replacement of accelerator
sensor
Monitor the accelerator sensor by the
diagnosis tool.
Water temperature sensor signal error
(Error at which level ECU can’t detect)
c
c
c
c
c
Replacement of water temperature sensor Monitor the cooling water temperature by
the diagnosis tool.
Speed sensor signal error
(Cause of noise etc. that ECU can’t
detect)
c
c
c
c
c
c
Cleaning or replacement of speed sensor
Repair or replacement of fuel injection
pump
Monitor the engine rotational speed by
the diagnosis tool.
Rack position sensor signal error
(Level that ECU can’t detect)
c
c
c
c
c
c
Repair or replacement of fuel injection
pump
Monitor the rack position sensor signal by
the diagnosis tool.
Operation defect of rack actuator
(Level that ECU can’t detect)
c
c
c
c
c
c
Repair or replacement of fuel injection
pump
Check the movement of rack actuator by
the diagnosis tool.
ECU failure lamp disconnected
c
Replace the lamp.
Repair or replace the harness.
ECU faulty (ECU self diagnosis failure)
c
c
c
c
c
Replace the ECU.
Symptoms and conditions of failures
Cause
Defective start
Engine stall
after start
Defective rotation control
Insufficient
engine output
Noise/vibration
Lubricant
Cooling
water
Intake
Exhaust
Fuel
Electrics/electronics
Action
Referenced page number
Starter not
rotate
Starter
rotates
Exhaust
fume
Speed change
by accelerator n
o
t available (constant sp
eed)
Without load
At work
Exhaust color
Knocking noise at combustion to
o high
Combu
s
tion noise
uneven
Noise other t
han combustion from engine
Engine vibration
too big
Lubricant consumption too much
Lubricant dilu
ted with fuel
Lubricant mixe
d wit
h water
Oil pre
s
sure to
o low
(oil pressure lamp
on)
Overheated (water temperat
ure lamp on)
Water
temperature too low
Pressure dow
n (air cleaner lamp on)
Pr
essur
e
up
At work
Blow-by too much
Exhaust
temperatu
re up
Fu
el consumption too much
Fu
el mixed with water (oil-water separator
lamp on
)
Fu
el filter contaminated too e
arly
Battery charg
e defect (charge
lamp o
n)
ECU indica
tor lamp flashing
ECU indica
tor lamp not on just after key-on
(2 seco
nds)
Prescribed ECU control fun
c
tion not op
erate
Fu
se meltdow
n, disconnection
(repe
ated)
ECU indica
tor lamp not on just after key-on
ECU indica
tor lamp on just
after key-on (2 se
conds)
Engine not start (not even initial comb
ustion)
Engine not start (stall after serial combustion)
Engine starts la
ter then e
v
er
None
Little
Much
Specified speed setti
ng not available
Poor acceleration
Retu
rn to low speed not
smooth
Hunt
ing
Hunt
ing
Nor
m
al
White
Blac
k
White exh
aust color
Black exhaust color
TNV_DI_SM_A4-Troubleshooting.book 226 ページ 2007年11月15日 木曜日 午後5時27分