2005 SUZUKI JIMNY ignition

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Fuel pressure relief procedure
After making sure that engine is cold, release fuel pressure as fol-
lows.
1) Place transmission gear shift lever in “Neutral” (Shift selector
lever to “P” range for A/T model), set parking brake, and
block drive wheels.
2) Remove relay box cover.
3) Disconnect fuel pump relay (1) from its connector.
4) Remove fuel filler cap to release fuel vapor pressure in fuel
tank and then reinstall it.
5) Start engine and run it till it stops for lack of fuel. Repeat
cranking engine 2-3 times for about 3 seconds each time to
dissipate fuel pressure in lines. Fuel connections are now
safe for servicing.
6) Upon completion of servicing, connect fuel pump relay (1) to
its connector.
Fuel leakage check procedure
After performing any service on fuel system, check to make sure
that there are no fuel leakages as follows.
1) Turn ON ignition switch for 3 seconds (to operate fuel pump)
and then turn it OFF.
Repeat this (ON and OFF) 3 or 4 times and apply fuel pres-
sure to fuel line. (till fuel pressure is felt by hand placed on
fuel feed hose.)
2) In this state, check to see that there are no fuel leakages
from any part of fuel system. CAUTION:
This work must not be done when engine is hot. If done
so, it may cause adverse effect to catalyst.

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Engine Diagnosis
General Description
This vehicle is equipped with an engine and emission control system which are under control of ECM.
The engine and emission control system in this vehicle are controlled by ECM. ECM has an On-Board Diagnos-
tic system which detects a malfunction in this system and abnormality of those parts that influence the engine
exhaust emission. When diagnosing engine troubles, be sure to have full understanding of the outline of “On-
Board Diagnostic System” and each item in “Precaution in Diagnosing Trouble” and execute diagnosis accord-
ing to “ENGINE DIAGNOSTIC FLOW TABLE”.
There is a close relationship between the engine mechanical, engine cooling system, ignition system, exhaust
system, etc. and the engine and emission control system in their structure and operation. In case of an engine
trouble, even when the malfunction indicator lamp (MIL) doesn’t turn ON, it should be diagnosed according to
this flow table.
On-Board Diagnostic System (Vehicle with
Immobilizer Indicator Lamp)
ECM in this vehicle has following functions.
When the ignition switch is turned ON with the engine at a
stop, malfunction indicator lamp (MIL) (1) turns ON to check
the bulb of the malfunction indicator lamp (1).
When ECM detects a malfunction which gives an adverse
effect to vehicle emission while the engine is running, it
makes the malfunction indicator lamp (1) in the meter cluster
of the instrument panel turn ON or flash (flashing only when
detecting a misfire which can cause damage to the catalyst)
and stores the malfunction area in its memory.
(If it detects that continuously 3 driving cycles are normal
after detecting a malfunction, however, it makes MIL (1) turn
OFF although DTC stored in its memory will remain.)
As a condition for detecting a malfunction in some areas in
the system being monitored by ECM and turning ON the
malfunction indicator lamp (1) due to that malfunction, 2 driv-
ing cycle detection logic is adopted to prevent erroneous
detection.
When a malfunction is detected, engine and driving condi-
tions then are stored in ECM memory as freeze frame data.
(For the details, refer to description on Freeze frame data.)
It is possible to communicate by using not only SUZUKI scan
tool (2) but also generic scan tool. (Diagnostic information
can be accessed by using a scan tool.)
WARM-UP CYCLE
A warm-up cycle means sufficient vehicle operation such that the
coolant temperature has risen by at least 22 °C (40 °F) from
engine starting and reaches a minimum temperature of 70 °C
(160 °F).

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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
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 is
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 connecting diagnosis switch terminal
(2) and ground terminal (4) of monitor connector (3) with a
service wire (5) 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.

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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” for trouble
shooting (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.
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
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.
[Without Using SUZUKI Scan Tool] (Vehicle Without
Immobilizer Indicator Lamp)
1) Check malfunction indicator lamp referring to “Malfunction
Indicator Lamp Check” in this section.
2) With the ignition switch OFF position, connect diagnosis
switch terminal (3) and ground terminal (2) in monitor con-
nector (1) with service wire (4).
3) With the ignition switch ON position and leaving engine OFF,
read DTC from flashing pattern of malfunction indicator
lamp. Refer to “Diagnostic Trouble Code Table”.
If lamp does not flash or remains ON or OFF, go to “Diag-
nostic Flow Table A-4”.

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4) After completing the check, turn the ignition switch OFF posi-
tion and disconnect service wire from monitor coupler.
Diagnostic trouble code (DTC) clearance
[Using SUZUKI Scan Tool]
1) Connect SUZUKI scan tool to data link connector in the
same manner as when making this connection for DTC
check.
2) Turn ignition switch ON.
3) Erase DTC and pending DTC according to instructions dis-
played on scan tool. Refer to scan tool operator’s manual for
further details.
4) After completing the clearance, turn ignition switch off and
disconnect scan tool from data link connector.
[Without Using SUZUKI Scan Tool]
1) Turn the ignition switch OFF position.
2) Disconnect battery negative cable for specified time below to
erase diagnostic trouble code stored in ECM memory and
reconnect it.
Time required to erase DTC NOTE:
If abnormality or malfunction lies in two or more areas,
malfunction indicator lamp indicates applicable codes
three times each.
And flashing of these codes is repeated as long as
diagnosis terminal is grounded and ignition switch is
held at ON position.
Take a note of diagnostic trouble code indicated first.
NOTE:
DTC and freeze frame data stored in ECM memory are
also cleared in following cases. Be careful not to clear
them before keeping their record.
When power to ECM is cut off (by disconnecting bat-
tery cable, removing fuse or disconnecting ECM con-
nectors)
When the same malfunction (DTC) is not detected
again during 40 engine warm-up cycles.
Ambient temperature Time to cut power to ECM
Over 0 °C (32 °F) 30 sec. or longer
Under 0 °C (32 °F)Not specifiable.
Select a place with higher than
0 °C (32 °F) temperature.

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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” performed? 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 Sec-
tion 6G.
4 Does engine start? Go to Step 5. Go to Step 9.
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 Diagnosis
Table”.
6 Is SUZUKI scan tool available? Go to Step 8. Go to Step 7.
7 Check ignition timing as follows :
1) Connect test switch terminal (2) of monitor
coupler (1) to ground. See Fig. 2.
2) Remove air cleaner bolt and crips and shift
air cleaner position to observe ignition tim-
ing.
3) Using timing light (1), check initial ignition
timing.
See Fig. 4.
Is it 5° ± 3° BTDC at specified idle speed?Go to “Engine Diagnosis
Table”.Check ignition control
related parts referring to
Section 6F.
8 Check ignition timing as follows :
1) Select “MISC” mode on SUZUKI scan tool
and fix ignition timing to initial one. See Fig.
3.
2) Remove air cleaner bolt and crips and shift
air cleaner position to observe ignition tim-
ing.
3) Using timing light (1), check initial ignition
timing. See Fig. 4.
Is it 5° ± 3° BTDC at specified idle speed?Go to “Engine Diagnosis
Table”.Check ignition control
related parts referring to
Section 6F.
9 Check immobilizer system malfunction as fol-
lows (if equipped) :
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 Sec-
tion 8G.Go to Step 10.

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[A] Fig. 1 for Step 5 / [B] Fig. 2 for Step 7 / [C] Fig. 3 for Step 810 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 return pressure (returning sounds) felt
from fuel feed hose (1) when ignition switch is
turned ON?Go to Step 12. Go to Step 11.
11 Check fuel pump for operating.
1) Was fuel pump operating sound heard from
fuel filler for about 2 seconds after ignition
switch ON and stop?Go to “Diag. Flow Table
B-3”.Go to “Diag. Flow Table
B-2”.
12 Check ignition spark as follows :
1) Disconnect injector couplers.
2) Remove spark plugs and connect them to
high tension cords.
3) Ground spark plugs.
4) Crank engine and check if each spark plug
sparks.
Is it in good condition?Go to Step 13. Go to “Ignition Spark Test”
in Section 6F.
13 Check fuel injector for operation as follows :
1) Install spark plugs and connect injector con-
nectors.
2) Using sound scope (2), check operating
sound of each injector (3) when cranking
engine. See Fig. 6.
Was injector operating sound heard from all
injectors?Go to “Engine Diagnosis
Table”.Go to “Diag. Flow Table
B-1”. Step Action Yes No
[B] : When not using SUZUKI scan tool :
[C] : When using SUZUKI scan tool

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[D] Fig. 4 for Step 7 or 8 / [E] Fig. 5 for Step 10 / [F] Fig. 6 for Step 13
Engine diagnosis table
Perform troubleshooting referring to following table when ECM has no DTC and no abnormality found in visual
inspection and engine basic inspection previously.
Condition Possible Cause Reference Item
Hard Starting
(Engine cranks OK)Faulty ignition coil Ignition coil assembly in Section 6F.
Faulty CMP sensing rotor or CKP sensing
rotorCMP sensing rotor or CKP sensing
rotor inspection in Section 6E.
Faulty idle air control system Diagnostic Flow Table B-4
Faulty ECT sensor, TP sensor, CKP sen-
sor, CMP sensor or MAP sensorECT sensor, TP sensor, CKP sensor,
CMP sensor or MAP sensor in Sec-
tion 6E.
Fuel pressure out of specification Diagnostic Flow Table B-3
Faulty fuel injector Diagnostic Flow Table B-1
Faulty ECM Inspection of ECM and its circuit in
this section.
Malfunctioning PCV system PCV system in Section 6E.
Low compression Compression check in Section 6A1.
Improper valve lash Valve lash in Section 6A1.
Improper valve timing Timing chain and chain tensioner in
Section 6A1.
Compression leak from valve seat Valves and cylinder head in Section
6A1.
Sticky valve stem Valves and cylinder head in Section
6A1.
Weak or damaged valve springs Valves and cylinder head in Section
6A1.
Compression leak at cylinder head gasket Valves and cylinder head in Section
6A1.
Sticking or damaged piston ring Pistons, piston rings, connecting rods
and cylinders in Section 6A1.
Worn piston, ring or cylinder Pistons, piston rings, connecting rods
and cylinders in Section 6A1.