Page 445 of 687
Downloaded from www.Manualslib.com manuals search engine 6-88 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0420 Catalyst System Efficiency below Threshold
CIRCUIT DESCRIPTION
ECM monitors oxygen concentration in the exhaust gas which has passed the three way catalytic converter by
HO2S-2.
When the catalyst is functioning properly, the variation cycle of HO2S-2 output voltage (oxygen concentration) is
slower than that of HO2S-1 output voltage because of the amount of oxygen in the exhaust gas which has been
stored in the catalyst.
REFERENCE
1. Heated oxygen sensor-1 3. Three way catalytic converter 5. To the sensor [B] : Case of TYPE B is shown
(See NOTE)
2. Warm up three way catalytic
converter4. Heated oxygen sensor-2 [A] : Case of TYPE A is shown
(See NOTE)
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
1. Engine running at closed loop
condition2. Fuel cut 3. Idle after fuel cut [A] : Oscilloscope waveforms
Page 451 of 687

Downloaded from www.Manualslib.com manuals search engine 6-94 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC P0500 (DTC No.16) Vehicle Speed Sensor (VSS) Malfunction
CIRCUIT DESCRIPTION
DTC CONFIRMATION PROCEDURE
1) Clear DTC and warm up engine to normal operating temperature.
2) Increase vehicle speed to 50 mph, 80 km/h in 3rd gear or “2” range while observing vehicle speed displayed
on scan tool.
3) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for 4
sec. or more.
4) Check pending DTC and DTC.
1. VSS 3. VSS connector [B] : Case of TYPE B is shown (See NOTE)
2. Combination meter [A] : Case of TYPE A is shown (See NOTE)
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
VSS signal not inputted while vehicle running in “D”
range or during fuel cut at deceleration.
✱
✱✱ ✱2 driving cycle detection logic, continuous monitoring“B/Or” circuit open
“Y” or “Bl/B” circuit open or short
VSS malfunction
ECM malfunction
Speedometer malfunction
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester.
Page 452 of 687
![SUZUKI JIMNY 2005 3.G Service Workshop Manual Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-95
INSPECTION
[A] Fig. 1 for Step 5 / [B] Fig. 2 for Step 4 and Step 6Step Action Yes No
1Was “Eng SUZUKI JIMNY 2005 3.G Service Workshop Manual Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-95
INSPECTION
[A] Fig. 1 for Step 5 / [B] Fig. 2 for Step 4 and Step 6Step Action Yes No
1Was “Eng](/manual-img/20/7588/w960_7588-451.png)
Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-95
INSPECTION
[A] Fig. 1 for Step 5 / [B] Fig. 2 for Step 4 and Step 6Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Does speedometer indicate vehicle speed? Go to Step 3. Go to Step 5.
3 Check Vehicle Speed Signal.
Is vehicle speed displayed on scan tool in step
2) and 3) of DTC confirmation procedure?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Go to Step 4.
4 1) Turn ignition switch to OFF position.
2) Disconnect combination meter connec-
tors.Refer to Section 8.
3) Turn ignition switch to ON position, without
running engine.
4) Measure voltage from terminal “c” of VSS
connector to ground. See Fig.2.
Is voltage within 4 – 5 V?Faulty speedometer.“Y” or “Y/G” wire open or
short.
Poor connection of ECM
connector terminal.
If OK, substitute a known-
good ECM and recheck.
5 1) With ignition switch at OFF position, discon-
nect VSS connector.
2) Turn ignition switch to ON position, without
running engine.
3) Measure voltage from terminal “a” to “b” of
VSS connector. See Fig.1.
Is voltage within 10 – 14 V?Go to Step 6.“Bl/B” or “B/Or” wire open
or short.
6 1) Measure voltage from terminal “c” of VSS
connector to ground. See Fig.2.
Is voltage more than 4 V?Go to Step 7.“Y” or “Y/G” wire open or
short.
Poor connection of ECM
connector terminal.
If OK, substitute a known-
good ECM and recheck.
7 1) Remove VSS.
2) Visually inspect VSS sensor signal rotor for
damage.
Was any damage found?Faulty VSS signal rotor. Poor connection of VSS
connector terminal.
If OK, substitute a known-
good VSS and recheck.
Page 456 of 687

Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-99
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.
Page 457 of 687
Downloaded from www.Manualslib.com manuals search engine 6-100 ENGINE GENERAL INFORMATION AND DIAGNOSIS
[A] Fig. 1 for Step 2 / [B] Fig. 2 for Step 3
Table 13 Check MAP Sensor
1) Remove MAP sensor from intake manifold
and connect vacuum pump gauge to MAP
sensor. See Fig. 2.
2) Connect scan tool to DLC and turn ignition
switch ON.
3) Check intake manifold absolute pressure
displayed on scan tool for specified value.
See Table 1.
Is check result satisfactory?Check air intake system
for air being drawn in and
engine compression.
If OK, then substitute a
known-good ECM and
recheck.Replace MAP sensor. Step Action Yes No
Applying Vacuum Displayed Value on Scan Tool
0 Barometric pressure
(Approx. 100 kPa, 760 mmHg)
027 kPa
200 mmHgBarometric pressure – 27 kPa
(Approx. 73 kPa, 560 mmHg)
67 kPa
500 mmHgBarometric pressure – 67 kPa
(Approx. 33 kPa, 260 mmHg)
Page 458 of 687

Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-101
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
Page 465 of 687
![SUZUKI JIMNY 2005 3.G Service Workshop Manual Downloaded from www.Manualslib.com manuals search engine 6-108 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 4 / [C] Fig. 3 for Step 6Step Action Yes SUZUKI JIMNY 2005 3.G Service Workshop Manual Downloaded from www.Manualslib.com manuals search engine 6-108 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 4 / [C] Fig. 3 for Step 6Step Action Yes](/manual-img/20/7588/w960_7588-464.png)
Downloaded from www.Manualslib.com manuals search engine 6-108 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION
[A] Fig. 1 for Step 3 / [B] Fig. 2 for Step 4 / [C] Fig. 3 for Step 6Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 Is SUZUKI scan tool available? Go to Step 3. Go to Step 4.
3 Check PNP signal (“D” range signal).
1) Connect SUZUKI scan tool to DLC with igni-
tion switch OFF. See Fig. 1.
2) Turn ignition switch ON and check PNP sig-
nal (“P/N” or “D” range) on display when
shifting selector lever to each range.
Is “D” range on display (Is 0 – 1 V indicated) no
matter which of “R”, “D”, “2” and “L” range posi-
tions selector lever may be at? See Table 1.Intermittent trouble or
faulty ECM. Check for
intermittent referring to
“Intermittent and Poor
Connection” in Section
0A.Go to Step 5.
4 Check PNP Signal (“D” range signal).
1) Turn ignition switch ON.
2) Check voltage at terminal E17-6 of ECM
connector connected. See Fig. 2.
Is “D” range on display (Is 0 – 1 V indicated) no
matter which of “R”, “D”, “2” and “L” range posi-
tions selector lever may be at? See Table 1.Intermittent trouble or
faulty ECM. Check for
intermittent referring to
“Intermittent and Poor
Connection” in Section
0A.Go to Step 5.
5Is “P/N” range on display (Is 10 – 14 V indi-
cated) when selector lever is at one of “R”, “D”,
“2” and “L” range positions only?Check transmission range
switch and circuits refer-
ring to Section 7B.Go to Step 6.
6 Check PNP signal circuit.
1) Turn ignition switch OFF.
2) Disconnect TCM connectors.
3) Check for proper connection to TCM at ter-
minal E21-5.
4) If OK, then check voltage at terminal E21-8
in TCM connector disconnected, with igni-
tion switch ON. See Fig. 3
Is it 10 – 14 V?“Y/B” circuit open, poor
transmission range sen-
sor connector connec-
tion, select cable
maladjusted, transmis-
sion range sensor malad-
justed or transmission
range sensor malfunction.
If all above are OK, sub-
stitute a known-good TCM
and recheck.“G/Y” circuit open or poor
E17-6 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
Page 471 of 687
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Table B-4 Idle Air Control System Check
INSPECTION
1. Main fuse 2. Fuse box 3. Main relay 4. IAC valve
Step Action Yes No
1 Check engine idle speed and IAC duty referring to
“Idle Speed / IAC Duty Inspection” in Section 6E.
Is idle speed within specification?Go to Step 2. Go to Step 4.
2 Is IAC duty within specification in Step 1? Go to Step 3. Check for followings :
Vacuum leak
EVAP canister purge
control system
Clog of IAC air pas-
sage
Accessory engine
load
Closed throttle posi-
tion (TP sensor)
Stuck of PCV valve