2000 SUZUKI SWIFT harness

6-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS
INSPECTION OF ECM AND ITS CIRCUITS
ECM and its circuits can be checked at ECM wiring couplers by
measuring voltage and resistance.
VOLTAGE CHECK
1) Remove ECM (1) from vehicle body referring to Section 6E.
2) Check voltage at each terminal of couplers (2) connected.CAUTION:
ECM cannot be checked by itself. It is strictly prohibited
to connect voltmeter or ohmmeter to ECM with coupler
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
1. ECM
2. ECM couplers (Viewed from harness side)
C42 (31P) C41 (24P) G02 (17P)1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 26 28 27 29 30 315 6
1 2 3 4 5 6 7
11 12
9 10 11 13 12 14 15 16
16 171 2
7 8
13 14 3 4
9 10
15 17 188
19 20 21 22 23 24
2
1

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-43
Resistance Check
1) Disconnect ECM couplers from ECM with ignition switch
OFF.
2) Check resistance between each terminal of connectors dis-
connected.
TERMINAL RESISTANCE TABLE
For TYPE A (Refer to NOTE in “ECM VOLTAGE VALUES TABLE” for applicable model) CAUTION:
Never touch terminals of ECM itself or connect voltmeter
or ohmmeter.
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
C42-7 to G02-6 HO2S-1 heater (if equipped) 5.0 – 6.4 Ω
C41-4 to G02-6 HO2S-2 heater (if equipped) 12.0 – 14.3 Ω
C42-9 to C41-5/6 No.1 injector 11.3 – 13.8 Ω
C42-21 to C41-5/6 No.2 injector 11.3 – 13.8 Ω
C42-31 to C41-5/6 No.3 injector 11.3 – 13.8 Ω
C42-8 to C41-5/6 No.4 injector 11.3 – 13.8 Ω
C41-2 to C41-5/6 EGR valve (stepper motor coil 1) (if equipped) 20 – 24 Ω
C41-9 to C41-5/6 EGR valve (stepper motor coil 2) (if equipped) 20 – 24 Ω
C41-8 to C41-5/6 EGR valve (stepper motor coil 3) (if equipped) 20 – 24 Ω
C41-17 to C41-5/6 EGR valve (stepper motor coil 4) (if equipped) 20 – 24 Ω
C42-4 to C41-5/6 EVAP canister purge valve 30 – 34 Ω
C41-19 to G02-6 Fuel pump relay 56 – 146 Ω
C41-1 to Body ground A/C compressor clutch 3 – 5.5 Ω
C41-18 to C41-5/6 Radiator fan control relay No.1 56 – 146 Ω
C41-10 to G02-17 Main relay 56 – 146 Ω
C42-1 to Body ground Ground Continuity
C42-2 to Body ground Ground Continuity
C42-3 to Body ground Ground Continuity

6-54 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 2
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 “RED/WHT” and “GRY/RED” wire termi-
nals.
3) If OK, then with ignition switch ON, check
voltage between each of “GRY/RED” or
“RED/WHT” wire terminals and body
ground. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“GRY/RED” wire open or
shorted to ground circuit
or shorted to power circuit
(See NOTE), “RED/WHT”
wire open or shorted to
ground, poor C42-26 con-
nection or C42-22 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.
Check MAP sensor according to “MAP Sensor
Individual Check” mentioned previously.
Is it in good condition?“GRY/RED” wire shorted
to “ORN” wire, “RED/
WHT” wire open, poor
C42-10 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 “GRY/RED” wire, it is possible that MAP sensor is also faulty.

6-56 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 2
Fig. 2 for Step 33 Check Wire Harness.
1) Disconnect IAT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to IAT sensor
at “LT GRN/BLK” and “ORN” wire terminals.
3) If OK, then with ignition switch ON, is volt-
age applied to “LT GRN/BLK” wire terminal
about 4 – 6 V? See Fig. 2.Go to Step 5.“LT GRN/BLK” wire open
or shorted to power, or
poor C42-15 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Does scan tool indicate – 40°C (– 40°F) at Step
2.Go to Step 6. Go to Step 5.
5 Check Wire Harness
1) Check intake air temp. displayed on scan
tool with ignition switch ON.
Is – 40°C (– 40°F) indicated?Replace IAT sensor.“LT GRN/BLK” wire
shorted to ground.
If wire is OK, substitute a
known-good ECM and
recheck.
6 Check Wire Harness.
1) Using service wire, connect IAT sensor con-
nector terminals.
2) Check intake air temp. displayed on scan
tool with ignition switch ON. See Fig. 3.
Is 119°C (246°F) indicated?Replace IAT sensor.“LT GRN/BLK” wire open
or poor C42-10 connec-
tion.
If wire and connection are
OK, substitute a known-
good ECM and recheck. Step Action Yes No

6-58 ENGINE GENERAL INFORMATION AND DIAGNOSIS
DTC CONFIRMATION PROCEDURE
1) Clear DTC, start engine and keep it at idle for 1 min.
2) Select “DTC” mode no scan tool and check DTC.
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check ECT Sensor and its Circuit.
1) Connect scan tool with ignition switch OFF.
2) Turn ignition switch ON.
3) Check engine coolant temp. displayed on
scan tool. See Fig. 1.
Is – 40°C (– 40°F) or 119°C (246°F) indicated?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0 A.
3 Check Wire Harness.
1) Disconnect ECT sensor connector.
2) Check engine coolant temp. displayed on
scan tool.
Is – 40°C (– 40°F) indicated?Replace ECT sensor.“LT GRN” wire shorted to
ground.
If wire is OK, substitute a
known-good ECM and
recheck.
4 Does scan tool indicate – 40°C (– 40°F) at Step
2.Go to Step 6. Go to Step 5.
5 Check Wire Harness.
1) Disconnect ECT sensor connector with igni-
tion switch OFF.
2) Check for proper connection to ECT sensor
at “ORN” and “LT GRN” wire terminals.
If OK, then with ignition switch ON, is voltage
applied to “LT GRN” wire terminal about 4 – 6
V? See Fig. 2.Go to Step 4.“LT GRN” wire open or
shorted to power, or poor
C42-14 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
6 Check Wire Harness.
1) Using service wire, connect ECT sensor
connector terminals. See Fig. 3.
2) Turn ignition switch ON and check engine
coolant temp. displayed on scan tool.
Is 119°C (246°F) indicated?Replace ECT sensor.“ORN” wire open or poor
C42-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-61
INSPECTION
Fig. 1 for Step 2Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check TP Sensor and Its Circuit.
1) Connect scan tool to DLC with ignition
switch OFF and then turn ignition switch
ON.
2) Check throttle valve opening percentage
displayed on scan tool. See Fig. 1.
Is it displayed 2% or less?
3) Check throttle valve opening percentage
displayed on scan tool while opening throt-
tle valve from idle position to full open posi-
tion. See Fig. 1.
Is it displayed 96% or higher?Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0 A.
3 Check Wire Harness.
1) Disconnect connector from TP sensor with
ignition switch OFF.
2) Check for proper connection to TP sensor at
“GRY/RED”, “GRY/BLU” and “ORN” wire
terminals.
3) If OK, then with ignition switch ON, check
voltage between each of “GRY/RED” or
“GRY/BLU” wire terminals and body
ground. See Fig. 2.
Is voltage about 4 – 6 V at each terminal?Go to Step 4.“GRY/RED” wire open,
“GRY/RED” wire shorted
to ground circuit or power
circuit or “GRY/BLU” wire,
“ORN” wire open or
shorted to ground circuit
or poor C42-22 or C41-3
(For TYPE A, See NOTE)
or C42-16 (For TYPE B,
See NOTE) connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.
4 Check TP Sensor.
1) Check resistance between terminals of TP
sensor. See Fig. 3.
Between 1 and 2 : 2.5 – 6.0 kΩ
Between 1 and 3 : 100 Ω – 20 kΩ
varying according to throttle valve opening
Are measured values within specifications?“ORN” wire open or poor
C42-10 connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.Replace TP sensor.

6-84 ENGINE GENERAL INFORMATION AND DIAGNOSIS
Fig. 1 for Step 3
Fig. 2 for Step 47 Check EVAP Canister Purge Valve for Closing.
1) Disconnect purge hose from EVAP canister purge
valve.
2) Place finger against the end of EVAP canister purge
valve.
3) Check that vacuum is not felt there, when engine is
cool and running at idle. See Fig. 6.
Is vacuum felt?Check EVAP control
system (See Section
6E1).Go to Step 8.
8 Check MAP Sensor for performance (See DTC P0105
Diag. Flow Table).
Is it in good condition?Go to Step 9. Repair or replace.
9 Check ECT Sensor for performance (See Section 6E1).
Is it in good condition?Go to Step 10. Replace engine
coolant temp. sen-
sor.
10 Check Parts or System which can cause engine rough
idle or poor performance.
Engine compression (See Section 6A1).
Valve lash (See Section 6A1).
Valve timing (Timing belt installation. See Section
6A1).
Are they in good condition?Check wire harness
and connection of
ECM ground, ignition
system and fuel injec-
tor for intermittent
open and short.Repair or replace. Step Action Yes No
1. Fuel pressure gauge & 3 way joint
2. Fuel feed hose
1
2
1

ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-89
INSPECTION
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE DIAG.
FLOW TABLE”.
2 Check CKP Sensor and Connector for proper
installation.
Is CKP sensor installed properly and connector
connected securely?Go to Step 3. Correct.
3 Check Wire Harness and Connection.
1) Disconnect connector from CKP sensor.
2) Check for proper connection to CKP sensor at
each terminal.
3) If OK, turn ignition switch ON and check for
voltage at each terminal of sensor connector
disconnected. See Fig. 1.
Terminal “B+” : 10 – 14 V
Terminal “Vout” : 4 – 5 V
Terminal “GND” : – 0 V
Is check result satisfactory?Go to Step 5. Go to Step 4.
4 Was terminal “Vout” voltage out of specification in
Step 3 check?“YEL/BLK” wire open,
short or poor connection.
If wire and connection are
OK, substitute a known-
good ECM and recheck.“BLK/RED” or “BLK/
ORN” wire open, short
or poor connection.
5 Check Ground Circuit for open.
1) Turn ignition switch OFF.
2) Check for continuity between “GND” terminal
of CKP sensor connector and engine ground.
Is continuity indicated?Go to Step 6.“BLK/ORN” wire open
or poor ground con-
nection.
6 Check CKP Sensor for operation.
1) Remove CKP sensor from sensor case.
2) Remove metal particles on end face of CKP
sensor, if any.
3) Connect each connector to ECM and CKP
sensor.
4) Turn ignition switch ON.
5) Check for voltage at terminal C42-23 of con-
nector connected to ECM by passing magnetic
substance (iron) while keeping approximately
1 mm (0.03 in.) gap with respect to end face of
CKP sensor. See Fig. 2 and 3.
Does voltage vary from low (0 –1 V) to high (4 – 5
V) or from high to low?Go to Step 7. Replace CKP sensor.
7 Check Signal Rotor for the following. See Fig. 4.
Damage
No foreign material attached
Is it in good condition?Intermittent trouble or
faulty ECM.
Check for intermittent
referring to “Intermittent
and Poor Connection” in
Section 0A.Clean rotor teeth or
replace CMP sensor.