2000 SUZUKI SWIFT Circuits

6-38 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
1 2
1. ECM (PCM)
coupler disconnected
2. Ohmmeter
RESISTANCE CHECK
1) Disconnect ECM (PCM) couplers from ECM (PCM) with ignition
switch OFF.
CAUTION:
Never touch terminals of ECM (PCM) itself or connect
voltmeter or ohmmeter.
2) Check resistance between each terminal of couplers discon-
nected.
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 20C (68F).
TERMINALSCIRCUITSTANDARD RESISTANCE
C01-8 to C03-20H02S-1 heater11.7 – 14.3 Ω
C02-19 to C03-20H02S-2 heater11.7 – 14.3 Ω
C02-12 to C02-2 / 15Fuel injector2.4 – 3.6 Ω
C02-7 to C02-2 / 15EVAP canister purge valve30 – 34 Ω
C02-21 to C03-20Fuel pump relay100 – 120 Ω
C02-16 to C02-2 / 15ISC actuator relay100 – 120 Ω
C02-25 to C02-2 / 15EFE heater relay100 – 120 Ω
C02-8 to Body groundShift solenoid-B8 – 20 Ω
C02-9 to Body groundShift solenoid-A8 – 20 Ω
C02-20 to C02-2 / 15Radiator fan control relay100 – 120 Ω
C02-22 to C02-14Main relay100 – 120 Ω
C02-1 to Body groundGroundContinuity
C02-13 to Body groundGroundContinuity
C02-26 to Body groundGroundContinuity

Main fuse Ignition switch
Main fuseMalfunction indicator lamp in combination meter
Relay box“IG COIL METER”
6-42 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE A-3 ECM (PCM) 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 sup-
plied to ECM (PCM).
INSPECTION
STEPACTIONYESNO
1Main Relay Operating Sound Check
Is operating sound of main relay heard at ignition switch ON?Go to Step 5.Go to Step 2.
2Main 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.
Between terminals 1 and 2: Infinity
Between terminals 3 and 4: 100 – 120 Ω
4) Check that there is continuity between terminals 1 and 2
when battery is connected to terminals 3 and 4. See Fig. 3.
Is main relay in good condition?Go to Step 3.Replace main
relay.
3Fuse Check
Is main “FI” fuse in good condition?Go to Step 4.Check for short in
circuits connected
to this fuse.
4ECM (PCM) Power Circuit Check
1) Turn OFF ignition switch, disconnect connectors from ECM
(PCM) and install main relay.
2) Check for proper connection to ECM (PCM) at terminals
C03-20, C02-2, C02-15 and C02-22.
3) If OK, then measure voltage between terminal C03-20 and
ground, C02-22 and ground with ignition switch ON.
Is each voltage 10 – 14 V?Go to Step 5.“B/W”, “W/R” or
“Bl / B” circuit
open.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-43
Fig. 1 for Step 2 Fig. 2 for Step 2 Fig. 3 for Step 2
1. Main relay
2. Relay box
STEPACTIONYESNO
5ECM (PCM) Power Circuit Check
1) Using service wire, ground terminal C02-22 and
measure voltage between terminal C02-2 and
ground at ignition switch ON.
Is it 10 – 14 V?Check ground circuits
“Bl / B” and “W / Bl” for
open.
If OK, then substitute a
known-good ECM
(PCM) and recheck.Go to Step 6.
6Is operating sound of main relay heard in Step 1?Go to Step 7.“W / R” or “W / Bl” wire
open.
7Main Relay Check
1) Check main relay according to procedure in
Step 2.
Is main relay in good condition?“W / R” or “W / Bl” wire
open.Replace main relay.

6-64 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Sensed
information
Exhaust
gasFuel
injector
A/F
mixtureSignal to decrease amount of fuel injection
Signal to increase amount of fuel injection
High voltage
Low voltage
INJECTORHEATED
OXYGEN
SENSOR-1
A / F mixture
becomes
richerOxygen
concentration
decreases
A / F mixture
becomes
leanerOxygen
concentration
increases ECM
(PCM)
ECM
(PCM)
Main
fuseIgnition switch“IG COIL METER”
Main relayTo other circuits
Injector resistor
To other
sensorFuel
injector
Heated oxygen sensor-1
HO2S-1
DTC P0171 FUEL SYSTEM TOO LEAN
DTC P0172 FUEL SYSTEM TOO RICH
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE

When following condition occurs while engine running under
closed loop condition.
–Air / fuel ratio too lean
Total fuel trim (short and long terms added) is
more than 30%
or
–Air / fuel ratio too rich
(Total fuel trim is less than –30%)
2 driving cycle detection logic, continuous monitoring.
Vacuum leaks (air drawn in).

Exhaust gas leakage.

Heated oxygen sensor-1 circuit
malfunction.

Fuel pressure out of specification.

Fuel injector malfunction (clogged or
leakage).

MAP sensor poor performance.

ECT sensor poor performance.

IAT sensor poor performance.

TP sensor poor performance.

EVAP control system malfunction.

PCV valve malfunction.

“IG
COIL
METER”
Main
fuseIgnition
switch
Main
relayTo other circuits
Injector resistor Fuel injector
6-96 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE B-1 FUEL INJECTOR CIRCUIT CHECK
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Injector Circuit Check
1) Check injector circuit for short.
Is fuel injected from injector at ignition switch ON?“Y/B” wire shorted to
ground or faulty
injector.
If wire and injector is
as specified
respectively and then
substitute known-
good ECM (PCM) and
recheck.Go to Step 3.
3Injector Check
1) Check injector for fuel Injection referring to FUEL
INJECTOR ON-VEHICLE INSPECTION in
Section 6E1.
Is fuel injected from injector at engine cranking?Go to Step 4.Go to Step 5.
4Injector Leakage Check
1) Check injector for leaks referring to FUEL
INJECTOR ON-VEHICLE INSPECTION in
Section 6E1.
Is it in good condition?Injector and its circuit
are in good condition.Faulty fuel injector.
5Check Injector for Operating Sound.
1) Using sound scope, check injector for operating
sound at engine cranking.
Is it detected?Proceed to DIAG.
FLOW TABLE B-2 and
B-3.Go to Step 6.

6-98 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Main
fuseIgnition
switchTo other circuits
Main
relay
Fuel pump relay
Fuel pump
CAUTION: Check to make sure that connection is
made between correct terminals. Wrong connection
can cause damage to ECM (PCM), wire harness, etc.
TABLE B-2 FUEL PUMP AND ITS CIRCUIT CHECK
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE
DIAG. FLOW
TABLE”.
2Check Fuel Pump Control System for Operation. See Fig. 1.
Is fuel pump heard to operate for 2 sec. after ignition switch
ON?Fuel pump circuit
is in good
condition.Go to Step 3.
3Check Fuel Pump for Operation.
1) Remove fuel pump relay from relay box with ignition
switch OFF.
2) Check for proper connection to relay at each terminals.
3) If OK, using service wire, connect terminals E28-1 and
E28-2 of relay connector. See Fig. 2.
Is fuel pump heard to operate at ignition switch ON?Go to Step 4.“P”, “B” or “W/Bl”
circuit open or fuel
pump malfunction.
4Check Fuel Pump Relay for Operation.
1) Check resistance between each two terminals of fuel
pump relay. See Fig.3.
Between terminals “1” and “2”: Infinity
Between terminals “3” and “4”: 100 – 120 Ω
2) Check that there is continuity between terminals “1” and
“2” when battery is connected to terminals “3” and “4”. See
Fig. 4.
Is fuel pump relay in good condition?“P/W” circuit open
or poor C02-21
connection.
If wire and
connection are
OK, substitute a
known-good ECM
(PCM) and
recheck.Replace fuel pump
relay.

A/C
amplifier(A / C ON output signal)
(A / C input signal)
6-102 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
TABLE B-4 A / C SIGNAL CIRCUITS CHECK (VEHICLE WITH A / C)
INSPECTION
STEPACTIONYESNO
1Check A / C (Input) Signal Circuit.
1) Check voltage at terminal C03-19.
While engine running and A / C switch
and / or heater blower switch OFF
(A / C is not operating) : 10 – 14 V
While engine running and both A / C
switch and heater blower switch ON
(A / C is operating) : About 0 V
Are check results as specified?Go to Step 2.
“Bl / R” wire open or
short.

Poor C03-19
connection.

Poor A / C amplifier
coupler connection
or faulty A / C
system.
2Check A / C ON (Output) Signal Circuit.
1) Check voltage at terminal C03-17.
While engine running and A / C switch
and / or heater blower switch OFF
(A / C is not operating) : About 0 V
While engine running at idle speed
and both A / C switch and heater blower
switch ON (A / C is operating) : 10 – 14 V
Are check results as specified?A / C control signal
circuits are in good
condition.
“Lg / R” wire open or
short.

Poor performance of
ECT sensor, TP
sensor.

Engine start signal
inputted or

Poor C03-17
connection.
If none of the above
exists, substitute a
known-good ECM
(PCM) and recheck.

6-1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (SFI FOR G13) 6-1-1
GENERAL INFORMATION6-1- 3 . . . . . . . . . . . . . .
ENGINE DIAGNOSIS6-1- 6 . . . . . . . . . . . . . . . . . . .
General Description 6-1- 6. . . . . . . . . . . . . . . . . . .
On-Board Diagnostic System 6-1- 6. . . . . . . . . .
Precaution in Diagnosing Trouble 6-1- 9. . . . . . .
Engine Diagnostic Flow Table 6-1-10. . . . . . . . . .
Customer Problem Inspection From 6-1-12. . .
Malfunction Indicator Lamp Check 6-1-13. . . .
Diagnostic Trouble Code Check 6-1-13. . . . . .
Diagnostic Trouble Code Clearance 6-1-14. . .
Diagnostic Trouble Code Table 6-1-15. . . . . . .
Fail-safe Table 6-1-18. . . . . . . . . . . . . . . . . . . . .
Visual Inspection 6-1-19. . . . . . . . . . . . . . . . . . .
Engine Basic Inspection 6-1-20. . . . . . . . . . . . .
Engine Diagnosis Table 6-1-22. . . . . . . . . . . . .
Scan Tool Data 6-1-29. . . . . . . . . . . . . . . . . . . . . . .
Inspection of ECM (PCM) and Its
Circuits 6-1-33. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Check 6-1-33. . . . . . . . . . . . . . . . . . . . .
Resistance Check 6-1-37. . . . . . . . . . . . . . . . . .
Component Location 6-1-38. . . . . . . . . . . . . . . . . .
Table A-1 MIL Circuit Check
(Lamp does not come on) 6-1-39. . . . . . . . . . . . Table A-2 MIL Circuit Check
(Lamp remains ON) 6-1-40. . . . . . . . . . . . . . . . . .
Table A-3 ECM (PCM) Power and
Ground Circuit Check 6-1-41. . . . . . . . . . . . . . . .
DTC P0105 MAP Circuit Malfunction 6-1-43. . . .
DTC P0110 IAT Circuit Malfunction 6-1-46. . . . .
DTC P0115 ECT Circuit Malfunction 6-1-48. . . .
DTC P0120 Throttle Position Circuit
Malfunction 6-1-50. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0121 Throttle Position Circuit
Range / Performance Problem 6-1-52. . . . . . . . .
DTC P0130 HO2S Circuit Malfunction
(Sensor-1) 6-1-54. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0133 HO2S Circuit Slow
Response (Sensor-1) 6-1-56. . . . . . . . . . . . . . . .
DTC P0134 HO2S Circuit No Activity
Detected 6-1-57. . . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0135 HO2S Heater Circuit
Malfunction (Sensor-1) 6-1-58. . . . . . . . . . . . . . .
DTC P0136 HO2S Circuit Malfunction
(Sensor-2) 6-1-60. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 HO2S Heater Circuit
Malfunction (Sensor-2) 6-1-63. . . . . . . . . . . . . . .
DTC P0171 Fuel System Too Lean 6-1-65. . . . .
DTC P0172 Fuel System Too Rich 6-1-65. . . . . .
SECTION 6-1
ENGINE GENERAL INFORMATION
AND DIAGNOSIS
(SFI FOR G13)
WARNING:
For vehicles equipped with Supplemental Restraint (Air Bag) System:

Service on and around the air bag system components or wiring must be performed only by an autho-
rized SUZUKI dealer. Refer to “Air Bag System Components and Wiring Location View” under “Gener-
al Description” in air bag system section in order to confirm whether you are performing service on
or near the air bag system components or wiring. Please observe all WARNINGS and “Service Precau-
tions” under “On-Vehicle Service” in air bag system section before performing service on or around
the air bag system components or wiring. Failure to follow WARNINGS could result in unintentional
activation of the system or could render the system inoperative. Either of these two conditions may
result in severe injury.

Technical service work must be started at least 90 seconds after the ignition switch is turned to the
“LOCK” position and the negative cable is disconnected from the battery. Otherwise, the system may
be activated by reserve energy in the Sensing and Diagnostic Module (SDM).
CONTENTS