2000 SUZUKI SWIFT engine

Display of fuel injection signal using oscilloscope
1. CMP sensor signal
2. Fuel injector signal
3. Fuel injection time
2V/Div.
20V/Div.1
2
10ms/Div
Waveforms at specified idle speed 3 Sensor rotor
in distributorCamshaft
position sensor
6-74 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC P0340 CAMSHAFT POSITION (CMP) SENSOR CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

No CMP sensor signal for 2 seconds at engine
cranking (CKP sensor signal is inputted).
CMP sensor circuit open or short.

Signal rotor teeth damaged.

CMP sensor malfunction, foreign material being
attached or improper installation.

ECM (PCM) malfunction.
Reference
Connect oscilloscope between terminals C01-2 and C01-10 of ECM (PCM) connector connected to ECM (PCM)
and check CMP sensor signal.
DTC CONFIRMATION PROCEDURE
1) Clear DTC.
2) Start engine and keep it at idle for 1 min.
3) Select “DTC” mode on scan tool and check DTC.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-75
Fig. 1 for Step 3 Fig. 2 for Step 5
“a”: Air gap
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Is DTC P1500 (Engine starter signal circuit
malfunction) detected?Go to DTC P1500
Diag. Flow Table.Go to Step 3.
3Check CMP Sensor for Resistance.
1) Measure resistance of CMP sensor by referring to
“CMP SENSOR (PICK UP COIL) RESISTANCE”
in SECTION 6F.
Is resistance within specified value?Go to Step 4.Faulty CMP sensor.
4Check Wire Harness.
1) With ignition switch at OFF position, disconnect
ECM (PCM) electrical connectors.
2) Measure resistance from terminal “C01-2” to
“C01-10” of ECM (PCM) connector. See Fig. 1.
Is resistance within 185 – 275 Ω at 20C (68F)?Go to Step 5.“W” or “Or” wire open
or short.
Poor connection of
CMP sensor
connector terminal.
5Check Air Gap Between Rotor Tooth and Sensor. See
Fig. 2.
1) Remove Distributor cap.
2) Visually inspect CMP sensor signal rotor for
damage.
3) Measure air gap by referring “SIGNAL ROTOR
AIR GAP” in Section 6F.
Was any damage found?Faulty CMP sensor
signal rotor.Poor connection of
ECM (PCM)
connector terminal.
If OK, substitute a
known-good ECM
(PCM) and recheck
CMP.

6-76 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Oscilloscope Waveforms
Engine running at
Closed loop conditionFuel
CutIdle after fuel cut 0.5 V / Div
2 sec. / Div Heated
oxygen
sensor-1
Warm up three way
catalytic converter (if equipped)
Three way catalytic converterTo other sensor
To other
sensors
Heated oxygen sensor-2
G
DTC P0420 CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD
CIRCUIT DESCRIPTION
ECM (PCM) 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
DTC DETECTING CONDITIONPOSSIBLE CAUSE

While vehicle running at constant speed under other
than high load.

Time from rich or lean switching command is output
till HO2S-2 output voltage crosses 0.45 V is less than
specified value.
2 driving cycle detection logic, monitoring once / 1
driving.
Exhaust gas leak

Three way catalytic converter malfunction

Fuel system malfunction

HO2S-2 malfunction

HO2S-1 malfunction

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-77
1) 2) 3) 4) 35 – 45 mph
(55 – 65 km / h)
30 – 40 mph
(50 – 60 km / h)
DTC CONFIRMATION PROCEDURE
WARNING:

When performing a road test, select a place where there is no traffic or possibility of a traffic accident
and be very careful during testing to avoid occurrence of an accident.

Road test should be carried out with 2 persons, a driver and tester, on a level road.
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–Engine coolant temp.: 70 – 11 0C, 158 – 230F
2) Start engine and drive vehicle at 40 – 47 mph, 65 – 75 km / h for 15 min. or longer.
While this driving, if “Catalyst Monitoring TEST COMPLETED” is displayed in “READINESS TESTS” mode and
DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, continue test driving.
3) Decrease vehicle speed at 28 – 34 mph, 45 – 55 km / h, and hold throttle valve at that opening position for 2 min.
and confirm that short term fuel trim vary within –20% –+20% range.
4) Stop vehicle (do not turn ignition switch OFF) and confirm test results according to following “Test Result Con-
firmation Flow Table”.
Test Result Confirmation Flow Table
STEPACTIONYESNO
1Check DTC in “DTC” mode and pending DTC in
“ON BOARD TEST” or “PENDING DTC” mode.
Is DTC or pending DTC displayed?Proceed to applicable
DTC Diag. Flow Table.Go to Step 2.
2Set scan tool to “READINESS TESTS” mode and
check if testing has been completed.
Is test completed?No DTC is detected
(confirmation test is
completed).Repeat DTC
confirmation
procedure.

6-78 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Short Term Fuel Trim.
Did short term fuel trim vary within –20% –+20%
range in step 3) of DTC confirmation test?Go to Step 3.Check fuel system.
Go to DTC P0171 / P0172
Diag. Flow Table.
3Check HO2S-2 for Output Voltage.
Perform steps 1) through 9) of DTC confirmation
procedure for DTC P0136 (HO2S-2 malfunction)
and check output voltage of HO2S-2 then.
Is over 0.6 V and below 0.3 V indicated?Replace three way
catalytic converter.Check “G” and “R”
wires for open and
short, and connections
for poor connection.
If wires and connections
are OK, replace
HO2S-2.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-79
Main
fuseMain relay
To other valves
EVAP canister
purge valve
EVAP canister
purge valveSurge
tank
Tank pressure
control valveFuel vapor separator
Fuel filter cap
Fuel
level
sensor
Fuel tank EVAP
canister
DTC P0443 PURGE CONTROL VALVE CIRCUIT MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
Canister Purge control valve circuit is opened
or shorted.
“R/G” circuit open or short

“W/BI” circuit open

Canister purge valve malfunction
DTC CONFIRMATION PROCEDURE
1) Clear DTC with ignition switch ON.
2) Select “DTC” mode on scan tool and check DTC.
INSPECTION
STEPACTIONYESNO
1Check EVAP canister purge valve operation
1) With ignition switch OFF, disconnect coupler
from canister purge valve.
2) Check resistance of EVAP canister purge
valve. See Fig. 1.
Resistance between
two terminals : 30 – 34 Ω at 20C (68F)
Resistance between
terminal and body : 1M Ω or higher
Is it as specified?“R/G” circuit open or
short.Replace EVAP canister
purge valve.

6-80 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 1
Main
fuseIgnition switch“IG COIL METER”
Radiator fan
relay
Radiator fan motor
DTC P0480 RADIATOR FAN CONTROL SYSTEM MALFUNCTION
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

Low voltage at terminal C02-20 when engine coolant
temp. is below 91C, 195F.
2 driving cycle detection logic, continuous monitoring.
“B/W” or “BI” circuit open or short

Radiator fan relay malfunction

ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Warm up engine until radiator cooling fan starts to operate.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-81
Fig. 1 for Step 2 Fig. 2 for Step 3
1. Radiator fan relay
2. Relay box
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Radiator Cooling Fan Relay and Its Circuit.
1) Turn ignition switch ON.
2) Check for voltage at terminal C02-20 of ECM
(PCM) connector connected, under following
condition. See Fig. 1.
When engine coolant temp. is lower than
96C, 205F and A / C switch turns OFF:
10 – 14 V
Is voltage as specified?Intermittent trouble or
faulty ECM (PCM).
Check for intermittent
referring to “Intermittent
and Poor Connection”
in Section 0A.Go to Step 3.
3Check Radiator Fan Control Relay.
1) Turn ignition switch OFF and remove radiator
fan relay.
2) Check for proper connection to the relay at
“B/W” and “Bl” wire terminals.
3) If OK, then measure resistance between
terminals a and b. See Fig. 2.
Is it 100 – 120 Ω?“B/W” or “Bl” circuit
open or short.
If wires and connections
are OK, substitute a
known-good ECM (PCM)
and recheck.Replace radiator fan
relay.