Downloaded from www.Manualslib.com manuals search engine 6-26 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Excessive engine oil
consumptionSticky piston ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston and cylinder Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston ring groove and ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Improper location of piston ring gap Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn or damaged valve stem seal Valves and cylinder head in Section
6A1.
Worn valve stem Valves and cylinder head in Section
6A1.
Low oil pressure
Improper oil viscosity ITEM1-3 Engine oil and oil filter
change in Section 0B.
Malfunctioning oil pressure switch Oil pressure switch in Section 8.
Clogged oil strainer Oil pan and oil pump strainer in Sec-
tion 6A1.
Functional deterioration of oil pump Oil pump in Section 6A1.
Worn oil pump relief valve Oil pump in Section 6A1.
Excessive clearance in various sliding
partsRefer to Section 6A1.
Engine noise
See NOTE below.Improper valve lash Valve lash in Section 6A1.
Worn valve stem and guide Valves and cylinder head in Section
6A1.
Weak or broken valve spring Valve springs in Section 6A1.
Warped or bent valve Valves and cylinder head in Section
6A1.
Loose camshaft housing bolts Camshaft in Section 6A1.
Worn piston, ring and cylinder bore Pistons and cylinders in Section 6A1.
Worn crankpin bearing Crankpin and connecting rod bearing
in Section 6A1.
Worn crankpin Crankpin and connecting rod bearing
in Section 6A1.
Loose connecting rod nuts Connecting rod in Section 6A1.
Low oil pressure Previously outlined.
Worn crankshaft journal bearing Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Worn crankshaft journal Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Loose lower crankcase (bearing cap) bolts Main bearings, Crankshaft and cylin-
der block in Section 6A1.
Excessive crankshaft thrust play Main bearings, Crankshaft and cylin-
der block in Section 6A1. Condition Possible Cause Reference Item
NOTE:
Before checking the mechanical noise, make sure that :
Ignition timing is properly adjusted.
Specified spark plug is used.
Specified fuel is used.
Downloaded from www.Manualslib.com manuals search engine 6-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS
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 at combination meter.
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 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 after30 – 37 kPa,
220 – 340 mmHg
✱
✱✱ ✱
ENGINE SPEED At idling with no load after warming upDesired 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 up5 – 16° BTDC
✱
✱✱ ✱
INTAKE AIR TEMP. At specified idle speed after warming upAmbient 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
✱
✱✱ ✱
THROTTLE POS
(THROTTLE POSITION)Ignition switch
ON / engine
stoppedThrottle valve fully closed 7 – 18 %
Throttle valve fully open 70 – 90 %
✱
✱✱ ✱O2S B1 S1 (HEATED OXY-
GEN SENSOR-1)At specified idle speed after warming up 0.01 – 0.95 V
Downloaded from www.Manualslib.com manuals search engine 6-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS
For TYPE A (See NOTE)
E189 Ignition switch 10 – 14 V Ignition switch ON
10 Main relay10 – 14 V Ignition switch OFF
0.4 – 1.5 V Ignition switch ON
11 Ignition switch 10 – 14 V Ignition switch ON
12 Rear defogger switch (if equipped)10 – 14 VIgnition switch ON and rear defogger
switch ON
0 – 1.3 VIgnition switch ON and rear defogger
switch OFF
13–– –
14Diag. Switch terminal (without
immobilizer indicator lamp)4 – 5 V Ignition switch ON
15Test switch terminal (without immo-
bilizer indicator lamp)4 – 5 V Ignition switch ON
16 A/C (input) signal10 – 14 VIgnition switch ON
A/C switch OFF
0 – 2 VIgnition switch ON
A/C switch ON
17 Lighting switch10 – 14 V Lighting switch ON
0 – 1.3 V Lighting switch OFF
18A/C condenser fan motor relay
(if equipped)0 – 1.0 V A/C is operating
10 – 14 V A/C is not operating
19 Fuel pump relay0 – 1 V For 2 seconds after ignition switch ON
10 – 14 V After the above time
20 Engine start signal 6 – 14 V While engine cranking
21 Stop lamp switch0 VIgnition switch ON
Stop lamp switch OFF
10 – 14 VIgnition switch ON
Stop lamp switch ON
22 Vehicle speed sensordeflect
between
0 – 1.6 and
4 – 14 VIgnition switch ON and rear right wheel
turned slowly with rear left wheel locked
23–– –
24–– – TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E171–– –
2 R-range signal (A/T)10 – 14 VIgnition switch ON and shift select switch
in R range
0 – 1.3 VIgnition switch ON and shift select switch
in other than R range
3 Blank––
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For TYPE B (See NOTE)
E174Blank––
5 Overdrive cut signal (A/T)0 – 1.0 VIgnition switch ON and ECT less than
60 °C
10 – 14 VIgnition switch ON and ECT more than
60 °C
6 D-range idle up signal (A/T)10 – 14 VIgnition switch ON and shift select switch
in other than P and N range
0 – 1.6 VIgnition switch ON and shift select switch
in P and N range
7 Stop lamp switch0 VIgnition switch ON
Stop lamp switch OFF
10 – 14 VIgnition switch ON
Stop lamp switch ON
8–– –
9 Ignition switch 10 – 14 V Ignition switch ON
10–– –
11 Vehicle speed sensordeflect
between
0 – 1.6 and
4 – 14 VIgnition switch ON and rear right wheel
turned slowly with rear left wheel locked
12 ABS signal (if equipped) 10 – 14 V Ignition switch ON
13 Engine start signal 6 – 14 V While engine cranking
14–– –
15–– –
16 Rear defogger switch (if equipped)10 – 14 V Ignition switch ON and rear defogger
switch ON
0 – 1.3 V Ignition switch ON and rear defogger
switch OFF
17 A/T failure signal (with immobilizer
indicator lamp) (A/T)–– TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E171 A/C evaporator temp. sensor 2.0 – 2.3 VIgnition switch ON
A/C evaporator temp. sensor at 25 °C
(77 °F)
2 R-range signal (A/T)10 – 14 VIgnition switch ON and shift select switch
in R range
0 – 1.3 VIgnition switch ON and shift select switch
in other than R range
3Blank––
4Blank––
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-97
[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 43 Check Idle Air Control System.
1) Connect SUZUKI scan tool to DLC with igni-
tion switch OFF, set parking brake and block
drive wheels. See Fig. 1.
2) Warm up engine to normal operating tem-
perature.
3) Clear DTC and select “MISC TEST” mode
on SUZUKI scan tool.
Is it possible to control (increase and reduce)
engine idle speed by using SUZUKI scan tool? Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
4 Check Idle Air Control System.
1) Remove IAC valve from throttle boy refer-
ring to “IAC Valve” in Section 6E.
2) Check IAC valve for operation referring to
“IAC Valve” in Section 6E. See Fig. 2.
Is check result satisfactory?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 5.
5 Check Wire Harness for Open and Short.
1) Turn ignition switch OFF.
2) Disconnect IAC valve connector.
3) Check for proper connection to IAC valve at
each terminals.
4) If OK, disconnect ECM connector.
5) Check for proper connection to ECM at
E19-6 terminal.
6) If OK, check “Bl/B”, “G/Y” and “B/R” circuit
for open and short.
Are they in good condition?Replace IAC valve and
recheck.Repair or replace. Step Action Yes No
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DTC P1450 Barometric Pressure Sensor Low / High Input
DTC P1451 Barometric Pressure Sensor Performance Problem
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Barometric pressure sensor is installed in ECM.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Turn ignition switch ON for 2 sec., crank engine for 2 sec. and run it at idle for 1 min.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
DTC P1450 :
Substitute a known-good ECM and recheck.
DTC P1451 :
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC P1450 :
Barometric pressure sensor voltage is 4.7 V or higher, or
1.6 V or lowerECM (barometric pressure sensor) malfunc-
tion
DTC P1451 :
Vehicle stopped
Engine cranking
Difference between barometric pressure and intake mani-
fold absolute pressure is 26 kPa, 200 mmHg or more.
Difference between intake manifold absolute pressure at
engine start and pressure after engine start is less than 1.3
kPa, 10 mmHg.
✱
✱✱ ✱2 driving cycle detection logic, monitoring once / 1 driving.ECM (barometric pressure sensor) malfunc-
tion
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 1) Connect scan tool to DLC with ignition
switch OFF. See Fig.1.
2) Turn ignition switch ON and select “DATA
LIST” mode on scan tool.
3) Check manifold absolute pressure.
Is it barometric pressure (approx. 100 kPa, 760
mmHg) at sea level?Substitute a known-good
ECM and recheck.Go to Step 3.
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DTC P1500 Engine Starter Signal Circuit Malfunction
CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON, crank engine and run it at idle for 3 min.
3) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
1. Starter 3. Ignition switch (starter switch) [A] : Case of TYPE A is shown (See NOTE) [C] : M/T vehicle
2. Transmission range sensor (switch) 4. Main fuse [B] : Case of TYPE B is shown (See NOTE) [D] : A/T vehicle
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
DTC DETECTING CONDITION POSSIBLE CAUSE
Low voltage at terminal E17-13 or E18-20 when cranking
engine or
High voltage at terminal E17-13 or E18-20 after starting
engine.
✱
✱✱ ✱2 driving cycle detection logic, continuous monitoring.“B/Y” circuit open
ECM malfunction
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INSPECTION
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check for voltage at terminal E17-13 (Case of
TYPE A) (See NOTE) or E18-20 (Case of TYPE
B) (See NOTE) of ECM connector connected,
under following condition.
Engine starter signal specification
While engine cranking : 6 – 10 V
After starting engine : 0 V
Is voltage as specified?Poor E17-13 (Case of
TYPE A) (See NOTE) or
E18-20 (Case of TYPE B)
(See NOTE) connection
or intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.
If wire and connections
are OK, substitute a
known-good ECM and
recheck.“B/Y” or “B/R” circuit
open.