6-10 ENGINE GENERAL INFORMATION AND DIAGNOSIS
ON-BOARD DIAGNOSTIC SYSTEM (VEHICLE
WITHOUT IMMOBILIZER INDICATOR LAMP)
ECM diagnosis troubles which may occur in the area including
the following parts when the ignition switch is ON and the engine
is running, and indicates the result by turning on or flashing mal-
function indicator lamp (1).
Heated oxygen sensor (if equipped)
ECT sensor
TP sensor
IAT sensor
MAP sensor
CMP sensor
CKP sensor
Knock sensor (if equipped)
VSS
CPU (Central Processing Unit) of ECM
ECM and malfunction indicator lamp (1) operate as follows.
Malfunction indicator lamp (1) lights when the ignition switch
is turned ON (but the engine at stop) with the diagnosis
switch terminal ungrounded regardless of the condition of
Engine and Emission control system. This is only to check
the malfunction indicator lamp (1) bulb and its circuit.
If the above areas of Engine and Emission control system
are free from any trouble after the engine start (while engine
is running), malfunction indicator lamp (1) turns OFF.
When ECM detects a trouble which has occurred in the
above areas, it makes malfunction indicator lamp (1) turn ON
while the engine is running to warn the driver of such occur-
rence of trouble and at the same time it stores the trouble
area in ECM back-up memory. (The memory is kept as it is
even if the trouble was only temporary and disappeared
immediately. And it is not erased unless the power to ECM is
shut off for specified time below.)
ECM also indicates trouble area in memory by means of
flashing of malfunction indicator lamp (1) at the time of
inspection. (i.e. when diagnosis switch terminal (2) is con-
nected to ground terminal (3) with a service wire and ignition
switch is turned ON.)
NOTE:
When a trouble occurs in the above areas and disap-
pears soon while the diagnosis switch terminal is
ungrounded and the engine is running, malfunction
indicator lamp (1) lights and remains ON as long as the
trouble exists but it turns OFF when the normal condi-
tion is restored.
Time required to erase diagnostic trouble code mem-
ory thoroughly varies depending on ambient tempera-
ture as follows.
ODO TRIP AB
1
32
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-15
MALFUNCTION INDICATOR LAMP (MIL) CHECK
1) Turn ON ignition switch (but the engine at stop) and check
that MIL lights.
If MIL does not light up (or MIL dims), go to “Diagnostic Flow
Table A-1” for troubleshooting.
If MIL flushes, go to “Diagnostic Flow Table A-3” (vehicle
without immobilizer indicator lamp).
2) Start engine and check that MIL turns OFF.
If MIL remains ON and no DTC is stored in ECM, go to
“Diagnostic Flow Table A-2” for troubleshooting.
DIAGNOSTIC TROUBLE CODE (DTC) CHECK
[Using SUZUKI Scan Tool]
1) Prepare SUZUKI scan tool (Tech-1).
2) With ignition switch OFF, connect it to data link connector
(DLC) (1) located on underside of instrument panel at
driver’s seat side.
Special tool
(A) : SUZUKI scan tool
(B) : Mass storage cartridge
(C) : 16/14 pin DLC cable
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC, pending DTC and freeze frame data according to
instructions displayed on scan tool and print it or write it
down.
Refer to scan tool operator’s manual for further details.
If communication between scan tool and ECM is not possi-
ble, check if scan tool is communicable by connecting it to
ECM in another vehicle. If communication is possible in this
case, scan tool is in good condition. Then check data link
connector and serial data line (circuit) in the vehicle with
which communication was not possible.
5) After completing the check, turn ignition switch off and dis-
connect scan tool from data link connector.
ODO TRIP AB
1
(A)
(B) (C)
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-23
ENGINE BASIC INSPECTION
This check is very important for troubleshooting when ECM has detected no DTC and no abnormality has been
found in visual inspection.
Follow the flow table carefully.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check battery voltage.
Is it 11 V or more?Go to Step 3. Charge or replace battery.
3 Is engine cranked? Go to Step 4. Go to “DIAGNOSIS” in
Section 6G.
4 Does engine start? Go to Step 5. Go to Step 7.
5 Check idle speed as follows :
1) Warm up engine to normal operating temp.
2) Shift transmission to neutral position for M/T
(“P” position for A/T).
3) All of electrical loads are switched off.
4) Check engine idle speed with scan tool.
See Fig. 1.
Is it 650 – 750 r/min (700 – 800 r/min. for A/T
vehicle)?Go to Step 6. Go to “ENGINE DIAGNO-
SIS TABLE”.
6 Check ignition timing as follows :
1) When SUZUKI scan tool is not available,
disconnect scan tool from DLC and connect
test switch terminal of monitor connector to
ground. See Fig. 2.
When using SUZUKI scan tool, select
“MISC” mode on SUZUKI scan tool and fix
ignition timing to initial one. See Fig. 3.
2) Using timing light (1), check initial ignition
timing. See Fig. 4.
Is it 5° ± 3° BTDC at specified idle speed?Go to “ENGINE DIAGNO-
SIS TABLE”.Check ignition control
related parts referring to
Section 6F1.
7 Is immobilizer control system equipped? Go to Step 8. Go to Step 9.
8 Check immobilizer system malfunction as fol-
lows.
1) Check immobilizer indicator lamp or MIL
(malfunction indicator lamp) for flashing.
Is it flashing when ignition switch is turned to
ON position?Go to “DIAGNOSIS” in
Section 8G.Go to Step 9.
9 Check fuel supply as follows :
1) Check to make sure that enough fuel is
filled in fuel tank.
2) Turn ON ignition switch for 2 seconds and
then OFF. See Fig. 5.
Is fuel pressure felt from fuel feed hose (1)
when ignition switch is turned ON?Go to Step 11. Go to Step 10.
10 Check fuel pump for operating.
Was fuel pump operating sound heard from fuel
filler for about 10 seconds after ignition switch
ON and stop?Go to “DIAG. FLOW
TABLE B-3”.Go to “DIAG. FLOW
TABLE B-2”.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-31
SCAN TOOL DATA
As the data values given below are standard values estimated on the basis of values obtained from the normally
operating vehicles by using a scan tool, use them as reference values. Even when the vehicle is in good condi-
tion, there may be cases where the checked value does not fall within each specified data range. Therefore,
judgment as abnormal should not be made by checking with these data alone.
Also, conditions in the below table that can be checked by the scan tool are those detected by ECM and output
from ECM as commands and there may be cases where the engine or actuator is not operating (in the condi-
tion) as indicated by the scan tool. Be sure to use the timing light to check the ignition timing.
NOTE:
With the generic scan tool, only star (
✱) marked data in the table below can be read.
The triangle (
∆) marked data in the table below can not be read for vehicle without immobilizer indi-
cator lamp.
When checking the data with the engine running at idle or racing, be sure to shift M/T gear to the
neutral gear position and A/T gear to the “Park” position and pull the parking brake fully. Also, if
nothing or “no load” is indicated, turn OFF A/C, all electric loads, P/S and all the other necessary
switches.
SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
✱FUEL SYSTEM B1
(FUEL SYSTEM STATUS)At specified idle speed after warming up CLOSED (closed loop)
✱CALC LOAD
(CALCULATED LOAD
VALUE)At specified idle speed with no load after
warming up3 – 9%
At 2500 r/min with no load after warming up 12 – 17%
✱COOLANT TEMP.
(ENGINE COOLANT
TEMP.)At specified idle speed after warming up 80 – 100°C, 176 – 212°F
✱SHORT FT B1
(SHORT TERM FUEL
TRIM)At specified idle speed after warming up– 20 – +20%
✱LONG FT B1
(LONG TERM FUEL TRIM)At specified idle speed after warming up– 15 – +15%
✱MAP
(INTAKE MANIFOLD
ABSOLUTE PRESSURE)At specified idle speed with no load after
warming up30 – 37 kPa,
220 – 280 mmHg
✱ENGINE SPEED At idling with no load after warming up Desired idle speed
±50 r/min
✱VEHICLE SPEED At stop 0 km/h, 0 MPH
✱IGNITION ADVANCE
(IGNITION TIMING
ADVANCE FOR NO.1 CYL-
INDER)At specified idle speed with no load after
warming up6 – 16° BTDC
✱INTAKE AIR TEMP. At specified idle speed after warming up Ambient temp. :
+15°C (59°F)
–5°C (23°F)
✱MAF
(MASS AIR FLOW RATE)At specified idle speed with no load after
warming up1 – 4 gm/sec
At 2500 r/min with no load after warming up 4 – 9 gm/sec
6-32 ENGINE GENERAL INFORMATION AND DIAGNOSIS
✱THROTTLE POS
(ABSOLUTE THROTTLE
POSITION)Ignition switch
ON/engine
stoppedThrottle valve fully closed 7 – 18%
Throttle valve fully open 70 – 90%
✱O2S B1 S1
(HEATED OXYGEN SEN-
SOR-1)At specified idle speed after warming up 0.01 – 0.95 V
∆✱O2S B1 S2
(HEATED OXYGEN SEN-
SOR-2)When engine is running at 2000 r/min. for 3
min or longer after warming up.0.01 – 0.95 V
∆✱O2S FT B1 S1 At specified idle speed after warning up– 20 – +20%
∆✱DIS. WITH MIL ON––
DESIRED IDLE
(DESIRED IDLE SPEED)At idling with no load after warming up, M/T
at neutral, A/T at “P” rangeM/T 700 r/min
A/T 750 r/min
TP SENSOR VOLT
(THROTTLE POSITION
SENSOR OUTPUT VOLT-
AGE)Ignition switch
ON/engine
stoppedThrottle valve fully closed More than 0.2 V
Throttle valve fully open Less than 4.8 V
INJ PULSE WIDTH
(FUEL INJECTION PULSE
WIDTH)At specified idle speed with no load after
warming up2.0 – 3.6 msec.
At 2500 r/min with no load after warming up 2.0 – 3.6 msec.
IAC FLOW DUTY
(IDLE AIR CONTROL
FLOW DUTY)At idling with no load after warming up 5 – 25%
TOTAL FUEL TRIM At specified idle speed after warming up– 35 – +35%
BATTERY VOLTAGE Ignition switch ON/engine stop 12 – 14 V
CANIST PRG DUTY
(EVAP CANISTER PURGE
FLOW DUTY)–0 – 100%
CLOSED THROT POS
(CLOSED THROTTLE
POSITION)Throttle valve at idle position ON
Throttle valve opens larger than idle posi-
tionOFF
FUEL CUT When engine is at fuel cut condition ON
Other than fuel cut condition OFF
RADIATOR FAN
(RADIATOR FAN CON-
TROL RELAY)Ignition switch
ONEngine coolant temp. :
Lower than 95°C (203°F)OFF
Engine coolant temp. :
97.5°C (208°F) or higherON
ELECTRIC LOAD Ignition switch ON/Headlight, small light
and rear window defogger all turned OFFOFF
Ignition switch ON/Headlight, small light or
rear window defogger turned ONON
A/C SWITCH Engine running after warming up, A/C not
operatingOFF
Engine running after warming up, A/C oper-
atingON SCAN TOOL DATA VEHICLE CONDITION NORMAL CONDITION/
REFERENCE VALUES
6-34 ENGINE GENERAL INFORMATION AND DIAGNOSIS
IGNITION ADVANCE (IGNITION TIMING ADVANCE FOR NO.1 CYLINDER, °)
Ignition timing of NO.1 cylinder is commanded by ECM. The actual ignition timing should be checked by using
the timing light.
INTAKE AIR TEMP. (°C, °F)
It is detected by intake air temp. sensor and used to determine the amount of air passing into the intake manifold
as air density varies with temperature.
MAF (MASS AIR FLOW RATE, gm/s, lb/min)
It represents total mass of air entering intake manifold which is computed based on signals from MAP sensor,
IAT sensor, TP sensor, etc.
THROTTLE POS (ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position, throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1 (HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on exhaust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2 (HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst dete-
rioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter which indicates the ECM requested idle. If the engine is
not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle valve opening information in the form of voltage.
INJ PULSE WIDTH (FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive (valve opening) pulse which is output from ECM (but injector
drive time of NO.1 cylinder for multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL DUTY, %)
This parameter indicates current flow time rate within a certain set cycle of IAC valve (valve opening rate) which
controls the amount of bypass air (idle speed).
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting values of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
CANIST PURGE DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP purge solenoid
valve which controls the amount of EVAP purge.
0% means that the purge valve is completely closed while 100% is a fully open valve.
CLOSED THROTTLE POSITION (ON/OFF)
This parameter will read ON when throttle valve is fully closed, or OFF when the throttle is not fully closed.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped)
OFF : Fuel not being cut
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-35
RADIATOR FAN (RADIATOR FAN CONTROL RELAY, ON/OFF)
ON : Command for radiator fan control relay operation being output.
OFF : Command for relay operation not being output.
ELECTRIC LOAD (ON/OFF)
ON : Headlight, small light or rear window defogger ON signal inputted.
OFF : Above electric loads all turned OFF.
A/C SWITCH (ON/OFF)
ON : Command for A/C operation being output from ECM to A/C compressor magnet clutch.
OFF : Command for A/C operation not being output.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor
is set as 0 to 100%, however, with some models whose fuel tank capacity is smaller, the indicated fuel level may
be only 70% even when the fuel tank is full.
PNP SIGNAL (PARK/NEUTRAL POSITION SIGNAL, P/N RANGE or D RANGE)
It is detected by signal from TCM.
D range : A/T is in “R”, “D”, “2” or “L” range.
P/N range : A/T is in “P” or “N” range or the above signal is not inputted from TCM.
EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-37
ECM VOLTAGE VALUES TABLE
For TYPE A (See NOTE)
NOTE:
Type A is other than follows.
Type B is right hand steering vehicle equipped with fasten seat belt light and immobilizer control sys-
tem.
TERMINAL NO. CIRCUIT NORMAL VOLT-
AGECONDITION
C421 Ground––
2 Ground––
3 Ground––
4 EVAP canister purge valve 10 – 14 V Ignition switch ON
5 Engine coolant temp. and barometric
pressure signal for TCM (A/T)Indication
deflection
repeated 0 V
and 10 – 14 VIgnition switch ON
6 Idle air control valve 0 – 13 V At specified idle speed after engine warmed up
7 Heater of HO2S-1 (if equipped) 10 – 14 V Ignition switch ON
8 Fuel injector NO.4 10 – 14 V Ignition switch ON
9 Fuel injector NO.1 10 – 14 V Ignition switch ON
10 Sensor ground––
11 Camshaft position sensor 0 – 0.8 V and
4 – 6 VIgnition switch ON
12 Knock sensor (if equipped) 2.1 - 2.9 V Ignition switch ON
13 Heated oxygen sensor-1 (if equipped) Refer to DTC P0130 diag. flow table
CO adjusting resistor (if equipped)––
14 Engine coolant temp. sensor 0.55 - 0.95 V Ignition switch ON
Engine coolant temp. : 80°C (176°F)
15 Intake air temp. sensor 2.0 – 2.7 V Ignition switch ON
Intake air temp. : 20°C (68°F)
16 Test switch terminal (Vehicle without
immobilizer indicator lamp)4 – 6 V Ignition switch ON
17 Electric load signal (+) 0V Ignition switch ON
Small light and rear defogger OFF
10 – 14 V Ignition switch ON
Small light and rear defogger ON
18 A/C triple pressure switch 10 – 14 V A/C not operated
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensor 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor––
24–– –
25 Shield ground––
26 Manifold absolute pressure sensor 3.3 – 4.0 V Ignition switch ON
Barometric pressure : 100 kPa (760 mmHg)
27 Diag. Switch terminal (Vehicle without
immobilizer indicator lamp)4 – 6 V Ignition switch ON
28 Monitor output (Vehicle without immo-
bilizer indicator lamp)––
29 Blank––
30 Blank––
31 Fuel injector NO.3 10 – 14 V Ignition switch ON