Page 49 of 279
F3 SELF-DIAGNOSIS FUNCTfON
SELF-DIAGNOSIS FUNCTION
OUTLINE
Theself-diagnostic function and diagnosis procedure are the Same as for the previous 4WD model. How-
ever, there is an additional service (malfunction) code (N0.35) for the new modet.
13EOF3-321
SERVICE CODE NUM8ERS
Sensor or
subsystem
NE-signal
G stgnal
Knock sensor I Malfunction display
Cond &ion Fail-safe
Service
code no. Output signal pattern
No NE-signal
ON
-
02
OFF
M
No G srgnal Cancels two-group injection ON
03
OFF
ml
Open or short circuit
pressure sensor
F3-16
--
I
Page 50 of 279
SELF-DIAGNOSIS FUNCTION F3 I
Open or short crcuit
13EOFS322
Caution l If there is more than one failure present, the code numbers will be indicated in numerical or-
der, lowest number first.
l After repairing a failure, turn off the ignition switch, disconnect the negative battery cable,
and depress the brake pedal for at least twenty seconds to erase the service code from the
ECU memory. II
F3-17
Page 51 of 279

F3 SELF-DIAGNOSIS FUNCTION
:ODE NO. 25 {SOLENOlD VALVE - PRESSURE REGULATOR CONTROL) (Low temperature opoeration)
INSPECTION ACTION
Disconnect connector from ECU; IS there battery Yes Check ECU termrnal connector for poor
voltage at ECU terminal 2T (G/C) wrth Ignition connection
switch ON?
4 If OK, replace ECU
CT page F3-2
c3 If not OK, repatr or replace connector
NO Go to next step
2 In same condition as rn Step 1. is there battery Yes Repair or replace wlrrng harness (G/O)
voltage at sofenord vatve (PRC low temp.) con-
nector termrnal wrre (G/O)?
NO Go to next step
3 Is solenord valve (PRC low temp ) UK7 Yes Check for a short or open crrcuit in WII-
CT page F343 ing harness (main relay [FUEL INJ re-
lay] - solenoid valve [PRC low temp.])
NO Replace solenord valve (PRC tow temp.)
1
t3EOF3-323
CODE NO. 35 (SOLENOID VALVE - PRESSURE REGULATOR CONTROL) (High temperature opoeration)
STEP lNSPECTlON ACTlON
1 Disconnect connector from ECU: is there battery Yes Check ECU terminal connector for poor
voltage a? ECU terminal 22 (G) with rgnttlon connection
swttch ON7
4 If OK, replace ECU
J page F3-2
e If not OK, repair or replace connector
No Go to next step
2 In same condrtron as In Step 1, is there battery Yes
voltage at solenoid valve (PRC high temp.) con- Repair or replace wiring harness (G)
nector terminal wire (G)?
No Go to next step
3 Is solenoid valve (PRC high temp ) OK7 Yes Check for a short or open circuit In wir-
r;r page F343 ing harness (marn relay [FUEL INJ re-
WI - sofenord valve [PRC high temp.])
No Replace solenoid valve
(PRC high temp.)
f3EOF3-324
Circuit Diagram
ECU
I
2T 22 I
G
TO MAIN RELAY
I SOLENOID
VALVE
(PRC HIGH TEMP.)
F3-18 :3EOf3 32 5
--
TRW
RELAT
c
-..
INPUT
--
KNOCH
--
DIAGM
(TEN T
--
IGNITIi
(STAR1
--
E/L SIC
-a
P/S PR
--
A/c SYI
--
NEUTR
SWITCI
--
STUPb
--
ATMDI
SENSQ
-a
THRUI
-..
INfAk.1
--
AlFlFLC
--
UXYGE
--
WATEF
--
DlSfRl
Page 52 of 279
F3 TROUBLESHUOTING GUIDE
TROU8LESHOOTlNG GUIDE
RELATIONSHIP CHART
.
OUTPUT DEVICE
INPUT DEVICE
w
3
s
s
KNOCK SENSOR
0
0 0 0 DtAGNOStS CONNECTOR
(TEN TERMINAL)
0 0 0 IGNITION SWlTCH
(START POSITION) 0 0
0
0
0 0
0 0
0 0
0
0
0
0
0 0 0 0
E/L SIGNAL* 0
P/S PRESSURE SWITCH 0
0
A/C SWtTCH
NEUTRAL AND CLUTCH
SWITCHES
STOPLIGHT SWITCH
ATMOSPHERIC PRESSURE
SENSOR (IN ECU)
THROTTLE SENSOR
0 0 0 0
0
0
0 0’
0
0 0
0
0 0
0
’ 0
0
0 0 0 0 0 0 0
0 I
0 ~ INTAKE AIR THERMOSENSOR 0 0 0 0
0 -~
OXYGEN SENSOR
0 0 0 0 WATER THERMOSENSOR
A
0
* 0 0 0 c 0
13
3F3-32 IN, o . E/L SIGNAL: Blower fan control switch second position or higher, electric cooling fan operating, headlights
rear window defroster ON.
F3-19
i
Page 53 of 279

F3 TRUUBtESHOOTlNG GUIDE
IDIAGNOSTiC tNDEX
No. TFtOUBLESHOOTtNG ITEM DESCRIPTtON PAGE
1.
WI/I not crank or cranks slowly Refer to Engine Electrrcal System ‘1
2 Cranks normally but No combustion Engine cranks at normal speed but shows no sign of F3-22
will not start flrlng
3 Partial corn bustlon- Engine cranks at normal speed but shows only par- ‘1
When engine cold tial combustion and will not continue to run
4 Partial combustron- Engine cranks at normal speed and shows partial F3-25
After warm-up combustion but ~111 not continue runnrng after being
hot soaked
Cranks normally but Always Engine cranks at normal speed but rqurres exces- ‘1
hard to start sive cranktng time before starting
When engine cold Same condition as No. 5 when engine IS cold ‘1
Restarts normally after warm-up
After warm-up Same condition as No. 5 after running and betng hot F3-27
soaked
Starts normaNy when cold
1 8 1 Rough idle/
tsl Engine stalls at idle 1 Always [ Engine stalls or vibrates excessively at idle
r - 1 F3-29
r
Before warm-up 1 Engine stalls or vibrates excessively at idle during
I ‘1
10
11
12 After warm-up
When A/C, P/S,
or IX ON
Rough rdle/Englne stalts lus: after starting warm-up
Engine runs normally at idle during warm-up but
stalls or vibrates excessively atter warm-up
Engrne stalls or vtbrates excessrvely at idle when
NC, P/S, or E/L ON
Engine stalts or vibrates excessively lust after starting
tacceleratton from Idle1 F3-3 f
‘1
‘1
I I ’ I
I 13 High Idle speed after warm-up tdle speed excessively hrgh after warm-up ‘1
14 Idle moves up and down/idle hunts Engine speeds up and down periodically at Idle
F3-33
15 Engme stalls on deceleratron Engine unexpectedly stops running durrng or after
F3-35
deceleration
16 Engine statts suddenly (intermrttent) Engine intermittently stops runnrng
F3-36
17 Hesitates/Stumbles on acceleratton Flat spot occurs just after accelerator is depressed,
‘1
or m/Id ierkina occurs dunna acceleration
L I I
t 18 1 Surges while crulsng
1 Unexpected change In engine speed that is usually 1 ‘1
1 repetrtive
19 tack of power
20 Poor acceleration
21 Runs rough durrng deceleration/Backfire
22 Knocktng
23 Fuel odor Performance poor under load when throttle valve IS
wide open
Maximum speed reduced
Performance poor during acceleration
Engtne runs rough during deceleratron, and abnor-
mal combustion occurs in exhaust system
Abnormal combust!on accompanied by audible
“pinging” noise
( Gasoline odor in cabln ‘2
‘2
‘1
‘2
+1
24 Exhaust sulfur smell Exhaust gas has an unusual odor
25 High oil consumption Oil consumption excessive
b
26 Poor fuel economy Fuel economy unsatisfactory
27 A/C does not work
Blower fan operates, but magnetic clutch does not
l 1.. .Refet to 323 Workshop Manual (t 203-l O-89F). l 2...Re#er to 323 4-Wheet Drive Workshop Manual (1229-IO-89L). ‘1
‘2
‘1
l 1
13EOFS327
F3-20 -..
REAR I
--
--
Page 54 of 279

TRUU8LESH00TlNG GUIDE F3
13EOF3-328
13EOF3-329
1
PRECAUTIONS
Fuel Pressure Release and Servicing Fuel System
Fuel
in the fuel system remains under high pressure when the engine is not running.
a) Before disconnecting any fuel line, release the fuel pres-
sure from the fuel system to reduce the possibility of injury
or fire as discribed below.
1. Start the engine.
2. Push the rear seat cushion buttons and remove the
cushion.
3. Disconnect the fuel pump connector.
4. After the engine stalls, turn off the ignition switch.
5. Reconnect the fuet pump connector and install the rear
seat cushion.
b) Use a rag as protection from fuel spray when disconnect-
ing the fuel hoses.
Plug the hoses after removal.
c) When inspecting the fuel system, use a suitable fuel pres-
sure gauge.
Caution
l install hose clamps to secure the fuet pressure
gauge to the fuei fitter and the fuel main hose to pre-
vent fuel leakage.
Pinching Hose
When pinching an air hose-or a fuel hose with pliers, wrap
the hose with a rag to prevent damage,
F3-2 t
Page 55 of 279

F3 TROUBLESHOOTING GUIDE
SYMPTOM TROUSLESHOOTING
2 . CRANKS NORMALLY BUT WILL NOT START (NO COMBUSTION)
LIESCRIP-
l Engine cranks at normal speed but shows no sign of firing l Battery in normal condition
TION *Throttle valve not held fufly open while cranking (dechoke system not operating}
l Fuel in tank
UROOBLESHUOTlNG HINTS]
@ No spark
@.I low fuei tine pressure
l Ignition control malfunction @I Low engine compresslon l Ignition system component malfunction
@ No fuel injection
l Fuel pump inoperative l Ihjectors inoperative
;TEP
INSPECTION
I ACTION
1
Is strong btue spark visible at disconnected high- Yes Go to Step 3
tension lead?
NO Go to Step 2
2 Is “00” dlsplayed on Self-Dlagnosjs Checker
Yes
with ignltron switch ON? Check rgnltion system (Refer to
Troubleshooting “Misfire”)
c7 Section G
SYSTEM SELECT: 1 No
Service Code No. displayed Check for cause (Refer to specified
check sequence)
G- page
F3-16
“66” flashes
Check ECU termrnal 1F voltage
3 page W-45
Voltage: Battery vabage
(ignition switch ON)
W: SELF TEST C+ If OK, replace ECU
4 If not OK, check wiring
CT page F3-2
(ECU
- Self-Diagnosis Checker)
3
Connect diagnosis connector terminals F/P and
Yes
GND with jumper wire; IS fuel pump operating Does engine start in this condition?
sound heard wjth ignition switch ON?
4 If it does, check circuit-opening
relay
4 If it does not, go to Step 5
No Go to next step
F3-22
iTEF
6
8
Page 56 of 279
TROUBLESHOOTING GUlDE F3
STEP INSPECTION ACTlON
4
Is there buttery voltage at fuel pump connector Yes
* (G/R) with lgnitron switch ON and F/P terminal Check contmurty of fuel pump
between termrnafs G/R and 8
Check ctrcutt openmg relay
5
Is qector operating sound heard whtle engine IS Yes Go to Step 8
being cranked?
No Go to next step
CcI page F3-45
+ If 0K;check for a short cjrcult rn
wiring harness
(Injector reastor-Injector)
=D If not OK, replace Injector reststor
fuel Line pressure: 265-314 kPa
12.7-3.2 kgflcd, 38-46
psi)
if fuel return hose is clogged or
t, replace pressure
CT psge F3-3
F3-2 3