check engine SUZUKI JIMNY 2005 3.G Service Workshop Manual

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Inspection of ECM and Its Circuits
ECM and its circuits can be checked at ECM wiring connectors by
measuring voltage and resistance.
VOLTAGE CHECK
1) Remove ECM from body referring to Section 6E.
2) Check voltage at each terminal of connectors connected.CAUTION:
ECM cannot be checked by itself. It is strictly prohibited
to connect voltmeter or ohmmeter to ECM with connector
disconnected from it.
NOTE:
As each terminal voltage is affected by the battery volt-
age, confirm that it is 11 V or more when ignition switch
is ON.
1. ECM
2. ECM connectors (Viewed from harness side)

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Resistance Check
1) Disconnect ECM couplers (1) from ECM with ignition switch
OFF.
2) Check resistance between each terminal of couplers discon-
nected. CAUTION:
Never touch terminals of ECM itself or connect voltmeter
or ohmmeter (2).
CAUTION:
Be sure to connect ohmmeter probe from wire harness
side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table below represents that when parts
temperature is 20 °C (68 °F).
1. ECM coupler disconnected
2. Ohmmeter
TERMINALS CIRCUIT STANDARD RESISTANCE
E19-7 to E17-9
(For TYPE A) (See NOTE)HO2S-1 heater 5 – 6.4 Ω
E19-7 to E18-11
(For TYPE B) (See NOTE)
E18-4 to E17-9
(For TYPE A) (See NOTE)HO2S-2 heater 11.7 – 14.3 Ω
E19-9 to E19-2 No.1 injector 12.0 – 13.0 Ω
E19-21 to E19-2 No.2 injector 12.0 – 13.0 Ω
E19-31 to E19-2 No.3 injector 12.0 – 13.0 Ω
E19-8 to E19-2 No.4 injector 12.0 – 13.0 Ω
E19-28 to E19-2 EGR valve (stepper motor coil 4) 20 – 24 Ω
E19-17 to E19-2 EGR valve (stepper motor coil 3) 20 – 24 Ω
E19-29 to E19-2 EGR valve (stepper motor coil 2) 20 – 24 Ω
E19-18 to E19-2 EGR valve (stepper motor coil 1) 20 – 24 Ω
E19-4 to E19-2 EVAP canister purge valve 30 – 34 Ω
E18-19 to E17-9 (For
TYPE A) (See NOTE)Fuel pump relay 70 – 110 Ω
E18-19 to E18-11 (For
TYPE B) (See NOTE)
E18-1 to Body ground A/C compressor clutch 3 – 4.5 Ω
E18-18 to E19-2 A/C condenser fan control relay 70 – 110 Ω
E18-10 to E18-7 Main relay 70 – 110 Ω
E19-1 to Body ground Ground Continuity
E19-2 to Body ground Ground Continuity
E19-3 to Body ground Ground Continuity
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.

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Table A-1 Malfunction Indicator Lamp Circuit Check - Lamp Does Not Come
“ON” at Ignition Switch ON (But Engine at Stop)
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. Main fuse 4. Main relay 7.“IG” fuse [A] : Case of TYPE A is shown
(See NOTE)
2. Ignition switch 5. Malfunction indicator lamp in
combination meter8.“IG COIL METER” fuse [B] : Case of TYPE B is shown
(See NOTE)
3. Fuse box 6.“FI” fuse
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
Step Action Yes No
1 MIL Power Supply Check
1) Turn ignition switch ON.
Do other indicator / warning lights in combina-
tion meter comes ON?Go to Step 2.“IG” fuse blown, main fuse
blown, ignition switch mal-
function, “B/W” circuit
between “IG” fuse and
combination meter or
poor coupler connection
at combination meter.

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Table A-2 Malfunction Indicator Lamp Circuit Check - Lamp Remains “ON”
after Engine Starts
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to table A-1.
INSPECTION
2 ECM Power and Ground Circuit Check
Does engine start?Go to Step 3. Go to “Table A-5 ECM
Power and Ground Circuit
Check”.
If engine is not cranked,
go to “Diagnosis” in Sec-
tion 8G.
3 MIL Circuit Check
1) Turn ignition switch OFF and disconnect
connectors from ECM.
2) Check for proper connection to ECM at ter-
minal E18-2 (Case of TYPE A) (See NOTE)
or E17-9 (Case of TYPE B) (See NOTE).
3) If OK, then using service wire, ground termi-
nal E18-2 (Case of TYPE A) (See NOTE) or
E17-9 (Case of TYPE B) (See NOTE) in
connector disconnected.
Does MIL turn on at ignition switch ON?Substitute a known-good
ECM and recheck.Bulb burned out, “V/Y”
wire circuit open or “P”
wire shorted to ground. Step Action Yes No
Step Action Yes No
1 Diagnostic Trouble Code (DTC) check
1) Check DTC referring to DTC CHECK sec-
tion.
Is there any DTC(s)?Go to Step 2 of “Engine
Diag. Flow Table”.Go to Step 2.
2DTC check
1) Start engine and recheck DTC while engine
running.
Is there any DTC(s)?Go to Step 3.
3 MIL Circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
Does MIL turn ON at ignition switch ON?“V/Y” wire circuit shorted
to ground.Substitute a known-good
ECM and recheck.

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Table A-3 Malfunction Indicator Lamp Circuit Check - Mil Flashes at Ignition
Switch ON
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to table A-1.
INSPECTION
Table A-4 Malfunction Indicator Lamp Circuit Check - MIL Does Not Flash, Just
Remains ON or Just Remains OFF Even with Grounding Diagnosis Switch
Terminal
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Refer to table A-1.
INSPECTION
Step Action Yes No
1 MIL flashing pattern check :
1) With the ignition switch ON position, check
MIL flashing pattern.
Does MIL flashing pattern indicate DTC (diag-
nostic trouble code)?Go to Step 2. Go to “Diagnosis” in Sec-
tion 8G.
2 Diagnosis switch terminal check :
1) With the ignition switch ON position, check
voltage between E18-14 terminal of ECM
coupler and ground.
Is voltage 4 – 5 V?Substitute a known-good
ECM and recheck.“W/Bl” wire (diagnosis
switch terminal) shorted
to ground circuit.
If OK, substitute a known-
good ECM and recheck.
Step Action Yes No
1 MIL flashing pattern check :
1) With grounding diagnosis switch terminal
and turn the ignition switch ON position,
check voltage between E18-14 terminal of
ECM connector and ground.
Is voltage 0 – 1 V?Go to Step 2.“W/Bl” wire (diagnosis
switch terminal), “B” wire
of monitor connector
open.
If OK, substitute a known-
good ECM and recheck.
2 Test switch terminal circuit check :
1) With the ignition switch ON position, check
voltage between E18-15 terminal of ECM
connector and ground.
Is voltage 4 – 5 V?Substitute a known-good
ECM and recheck.“P” wire (test switch termi-
nal) shorted to ground cir-
cuit.
If OK, substitute a known-
good ECM and recheck.

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Table A-5 ECM Power and Ground Circuit Check - MIL Doesn’t Light at Ignition
Switch ON and Engine Doesn’t Start Though It Is Cranked Up
CIRCUIT DESCRIPTION
When the ignition switch tuned ON, the main relay turns ON (the contact point closes) and the main power is
supplied to ECM.
INSPECTION
1. Main fuse 4. Main relay 7.“IG” fuse [A] : Case of TYPE A is shown (See
NOTE)
2. Ignition switch 5. Malfunction indicator lamp in
combination meter8.“IG COIL METER” fuse [B] : Case of TYPE B is shown (See
NOTE)
3. Fuse box 6.“FI” fuse
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
Step Action Yes No
1 Main Relay Operating Sound Check
Is operating sound of main relay heard at ignition switch ON?Go to Step 5. Go to Step 2.
2 Main Relay Check
1) Turn OFF ignition switch and remove main relay (1).
2) Check for proper connection to main relay (1) at terminal 3 and 4.
3) Check resistance between each two terminals. See Fig. 1 and 2.
Main relay resistance
Between terminals A and B : Infinity
Between terminals C and D : 70 – 110
Ω
Ω Ω Ω (at 20 °C, 68 °F)
4) Check that there is continuity between terminals 1 and 2 when bat-
tery is connected to terminals 3 and 4. See Fig. 3.
Is main relay in good condition?Go to Step 3. Replace main
relay.

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[A] Fig. 1 for Step 2 and 3 / [B] Fig. 2 for Step 2 / [C] Fig. 3 for Step 23 Fuse Check
Is main “FI” fuse in good condition? See Fig. 1.Go to Step 4. Check for
short in cir-
cuits con-
nected to this
fuse.
4 ECM Power Circuit Check
1) Turn OFF ignition switch, disconnect connectors from ECM and
install main relay.
2) Check for proper connection to ECM at terminals E17-9 (Case of
TYPE A) (See NOTE) or E18-11 (Case of TYPE B) (See NOTE),
E18-10, E18-5 and E18-6.
3) If OK, then measure voltage between terminal E18-10 and ground,
E17-9 (Case of TYPE A) (See NOTE) or E18-11 (Case of TYPE B)
(See NOTE) and ground with ignition switch ON.
Is each voltage 10 – 14 V?Go to Step 5.“B/W”, “Or” or
“Bl/B” circuit
open.
5 ECM Power Circuit Check
1) Using service wire, ground terminal E18-10 and measure voltage
between terminal E18-5 and ground at ignition switch ON.
Is it 10 – 14 V?Check
ground cir-
cuits “B” and
“B/R” for
open.
If OK, then
substitute a
known-good
ECM and
recheck.Go to Step 6.
6 Is operating sound of main relay heard in Step 1? Go to Step 7.“Bl/B” or “B/
R” wire open.
7 Main Relay Check
1) Check main relay according to procedure in Step 2.
Is main relay in good condition?“Or” or “Bl/B”
wire open.Replace main
relay. Step Action Yes No
2.“F1” fuse

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DTC P0105 (DTC No.11) Manifold Absolute Pressure (MAP) Circuit Malfunc-
tion
CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
DTC DETECTING CONDITION POSSIBLE CAUSE
MAP sensor signal is 0.19 V or lower.
(Low pressure – High vacuums – Low voltage)
MAP sensor signal is 4.5 V or higher.
(High pressure – Low vacuums – High voltage)“B/Bl” circuit open
“Lg/R” circuit open or shorted to ground
“G” circuit open or shorted to ground
MAP sensor malfunction
ECM malfunction
NOTE:
When DTC P0120 is indicated together, it is possible that “Lg/R” circuit is open.
When DTC P0105 (No.11), P0110 (No.18) P0115 (No.19) P0120 (No.13) and P0460 are indicated
together, it is possible that “B/Bl” circuit is open.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Check MAP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF. See Fig. 1.
2) Turn ignition switch ON.
3) Check intake manifold pressure.
Is it 126 kPa (37.2 inHg) or 0 kPa (0 inHg)?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.

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[A] Fig. 1 for Step 2 / [B] Fig. 2 for Step 33 Check Wire Harness.
1) Disconnect MAP sensor connector with
ignition switch OFF.
2) Check for proper connection of MAP sensor
at “G” and “B/Bl” wire terminals.
3) If OK, then with ignition switch ON, check
voltage at each of “Lg/R” and “G” wire termi-
nals and body ground. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“Lg/R” wire open or
shorted to ground circuit
or shorted to power circuit
(See NOTE), “G” wire
open or shorted to
ground, poor E19-26 con-
nection or E19-22 con-
nection.
If wire and connection are
OK, confirm that MAP
sensor is normal and then
substitute a known-good
ECM and recheck.
4 Check MAP sensor according to “MAP Sensor
Individual Check” below.
Is it in good condition?“Lg/R” wire shorted to “G”
wire, “B/Bl” wire open,
poor E19-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace MAP sensor. Step Action Yes No
NOTE:
When battery voltage is applied to “Lg/R” wire, it is possible that MAP sensor is also faulty.

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MAP Sensor Individual Check
1) Disconnect connector from MAP sensor (1).
2) Remove MAP sensor (1).
3) Arrange 3 new 1.5 V batteries (2) in series (check that total
voltage is 4.5 – 5.0 V) and connect its positive terminal to
“Vin” terminal of sensor and negative terminal to “Ground”
terminal. Then check voltage between “Vout” and “Ground”.
Also, check if voltage reduces when vacuum is applied up to
400 mmHg by using vacuum pump (3).
If check result is not satisfactory, replace MAP sensor (1).
Output voltage (When input voltage is 4.5 – 5.5 V, ambient
temp. 20 – 30 °C, 68 – 86 °F)
4) Install MAP sensor (1) securely.
5) Connect MAP sensor (1) connector securely.ALTITUDE
(Reference)BAROMETRIC
PRESSUREOUTPUT
VOLTAGE
(ft) (m) (mmHg) (kPa) (V)
0
|
2 0000
|
610760
|
707100
|
943.3 – 4.3
2 001
|
5 000611
|
1 524Under 707
over 63494
|
853.0 – 4.1
5 001
|
8 0001 525
|
2 438Under 634
over 56785
|
762.7 – 3.7
8 001
|
10 0002 439
|
3 048Under 567
over 52676
|
702.5 – 3.3