2000 SUZUKI SWIFT ECM

GENERAL INFORMATION 0A-11

Be careful not to touch the electrical terminals of parts which
use microcomputers (e.g. electronic control unit like as
ECM, PCM, P / S controller, etc.). The static electricity from
your body can damage these parts.

Never connect any tester (voltmeter, ohmmeter, or whatever)
to electronic control unit when its coupler is disconnected.
Attempt to do it may cause damage to it.

Never connect an ohmmeter to electronic control unit with
its coupler connected to it. Attempt to do it may cause dam-
age to electronic control unit and sensors.

Be sure to use a specified voltmeter / ohmmeter. Otherwise,
accurate measurements may not be obtained or personal in-
jury may result. If not specified, use a voltmeter with high-im-
pedance (MΩ/ V minimum) or a digital type voltmeter.

When taking measurements at electrical connectors using a
tester probe (2), be sure to insert the probe from the wire har-
ness side (backside) of the connector (1).

When connecting meter probe (2) from terminal side of cou-
pler (1) because it can’t be connected from harness side, use
extra care not to bend male terminal of coupler of force its fe-
male terminal open for connection.
In case of such coupler as shown connect probe as shown
to avoid opening female terminal.
Never connect probe where (3) male terminal is supposed to
fit.

To avoid damage to the harness, protect its part which may
contact against a part forming a sharp angle by winding tape
or the like around it.

1. Check for loose connection
Sensor
ECM
0A-12 GENERAL INFORMATION

When checking connection of terminals, check its male half
for bend and female half for excessive opening and both for
locking (looseness), corrosion, dust, etc.

Before measuring voltage to check for electrical system,
check to make sure that battery voltage is 11 V or higher.
Such terminal voltage check at low battery voltage will lead
to erroneous diagnosis.
ELECTRICAL CIRCUIT INSPECTION
PROCEDURE
While there are various electrical circuit inspection methods, de-
scribed here is a general method to check its open and short circuit
by using an ohmmeter and a voltmeter.
OPEN CIRCUIT CHECK
Possible causes for the open circuit are as follows. As the cause is
in the connector or terminal in many cases, they need to be checked
particularly carefully.

Loose connection of connector.

Poor contact of terminal (due to dirt, corrosion or rust on it, poor
contact tension, entry of foreign object etc.).

Wire harness being open.
When checking system circuits including an electronic control unit
such as ECM, TCM, ABS control module, etc., it is important to per-
form careful check, starting with items which are easier to check.
1) Disconnect negative cable from battery.
2) Check each connector at both ends of the circuit being checked
for loose connection. Also check lock condition of connector if
equipped with connector lock.

0A-22 GENERAL INFORMATION
A
ABS : Anti-Lock Brake System
ATDC : After Top Dead Center
API : American Petroleum Institute
ATF : Automatic Transmission Fluid
ALR : Automatic Locking Retractor
AC : Alternating Current
A / T : Automatic Transmission
A / C : Air Conditioning
ABDC : After Bottom Dead Center
A / F : Air Fuel Mixture Ratio
A-ELR : Automatic-Emergency Locking
Retractor
B
B+ : Battery Positive Voltage
BTDC : Before Top Dead Center
BBDC : Before Bottom Dead Center
C
CKT : Circuit
CMP Sensor : Camshaft Position Sensor
(Crank Angle Sensor, CAS)
CO : Carbon Monoxide
CPP Switch : Clutch Pedal Position Switch
(Clutch Switch, Clutch Start
Switch)
CPU : Central Processing Unit
CRS : Child Restraint System
D
DC : Direct Current
DLC : Data Link Connector (Assembly
Line Diag. Link, ALDL, Serial
Data Link, SDL)
DOHC : Double Over Head Camshaft
DOJ : Double Offset Joint
DRL : Daytime Running Light
DTC : Diagnostic Trouble Code
(Diagnostic Code)
E
EBCM : Electronic Brake Control
Module, ABS Control Module
ECM : Engine Control Module
ECT Sensor : Engine Coolant Temperature
Sensor (Water Temp. Sensor,
WTS)
EGR : Exhaust Gas Recirculation
EGRT Sensor : EGR Temperature Sensor
(Recirculated Exhaust
Gas Temp. Sensor, REGTS)
EFE Heater : Early Fuel Evaporation Heater
(Positive Temperature
Coefficient, PTC Heater)
ELR : Emergency Locking Retractor
EPS : Electronic Power Steering
EVAP : Evaporative Emission
EVAP Canister : Evaporative Emission Canister
(Charcoal Canister)
F
4WD : 4 Wheel Drive
G
GEN : Generator
GND : Ground
H
HC : Hydrocarbons
HO2S : Heated Oxygen Sensor
I
IAC Valve : Idle Air Control Valve (Idle
Speed Control Solenoid Valve,
ISC Solenoid Valve)
IAT Sensor : Intake Air Temperature Sensor
(Air temperature Sensor, ATS)
ICM : Immobilizer Control Module
IG : Ignition
ISC Actuator : Idle Speed Control Actuator
(Motor)
ABBREVIATIONS AND SYMBOLS MAY BE USED IN THIS MANUAL
ABBREVIATIONS

Diagnostic Trouble Code Clearance 6-14. . . . .
Diagnostic Trouble Code Table 6-15. . . . . . . . .
Fail-safe Table 6-18. . . . . . . . . . . . . . . . . . . . . . .
Visual Inspection 6-19. . . . . . . . . . . . . . . . . . . . .
Engine Basic Inspection 6-20. . . . . . . . . . . . . . .
Engine Diagnosis Table 6-22. . . . . . . . . . . . . . .
Scan Tool Data 6-29. . . . . . . . . . . . . . . . . . . . . . .
Scan Tool Data Definitions 6-31. . . . . . . . . . . . .
Inspection of ECM (PCM) and Its Circuits 6-33
Voltage Check 6-33. . . . . . . . . . . . . . . . . . . . .
Resistance Check 6-37. . . . . . . . . . . . . . . . . .
Component Location 6-38. . . . . . . . . . . . . . . . . .
Table A-1 MIL Circuit Check
(Lamp does not come on) 6-39. . . . . . . . . . . .
Table A-2 MIL Circuit Check
(Lamp remains ON) 6-40. . . . . . . . . . . . . . . . . .
Table A-3 ECM (PCM) Power and Ground
Circuit Check 6-42. . . . . . . . . . . . . . . . . . . . . . .
DTC P0105 MAP Circuit Malfunction 6-44. . . .
DTC P0110 IAT Circuit Malfunction 6-46. . . . .
DTC P0115 ECT Circuit Malfunction 6-48. . . .
DTC P0120 Throttle Position Circuit
Malfunction 6-50. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0121 Throttle Position Circuit
Range / Performance Problem 6-52. . . . . . . . .
DTC P0130 HO2S Circuit Malfunction
(Sensor-1) 6-54. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0133 HO2S Circuit Slow
Response (Sensor-1) 6-56. . . . . . . . . . . . . . . .
DTC P0135 HO2S Heater Circuit
Malfunction (Sensor-1) 6-57. . . . . . . . . . . . . . .
DTC P0136 HO2S Circuit Malfunction
(Sensor-2) 6-59. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 HO2S Heater Circuit
Malfunction (Sensor-2) 6-62. . . . . . . . . . . . . . .
DTC P0171 Fuel System Too Lean 6-64. . . . .
DTC P0172 Fuel System Too Rich 6-64. . . . . .
DTC P0300 Random Misfire Detected 6-68. . .
DTC P0301 Cylinder 1 Misfire Detected 6-68. DTC P0302 Cylinder 2 Misfire Detected 6- 68.
DTC P0303 Cylinder 3 Misfire Detected 6- 68.
DTC P0335 CKP Sensor Circuit
Malfunction 6- 72. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0340 CMP Sensor Circuit
Malfunction 6- 74. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0420 Catalyst System Efficiency
Below Threshold 6- 76. . . . . . . . . . . . . . . . . . . .
DTC P0443 Purge Control Valve Circuit
Malfunction 6- 79. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0480 Radiator Fan Control
System Malfunction 6- 80. . . . . . . . . . . . . . . . . .
DTC P0500 Vehicle Speed Sensor
Malfunction (M / T) 6- 82. . . . . . . . . . . . . . . . . . .
DTC P0500 Vehicle Speed Sensor
Malfunction (A / T) 6- 84. . . . . . . . . . . . . . . . . . .
DTC P0505 Idle Control System
Malfunction 6- 86. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0510 Closed Throttle Position
Switch Malfunction 6- 88. . . . . . . . . . . . . . . . . .
DTC P0601 Internal Control Module
Memory Check Sum Error 6- 89. . . . . . . . . . . .
DTC P1250 EFE Heater Circuit
Malfunction 6- 90. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1450 Barometric Pressure
Sensor Low / High Input 6- 92. . . . . . . . . . . . . .
DTC P1451 Barometric Pressure Sensor
Performance Problem 6- 92. . . . . . . . . . . . . . . .
DTC P1500 Engine Starter Signal
Circuit Malfunction 6- 93. . . . . . . . . . . . . . . . . . .
DTC P1510 ECM (PCM) Back-up Power
Supply Malfunction 6- 94. . . . . . . . . . . . . . . . . .
Table B-1 Fuel Injector Circuit Check 6- 96. . . .
Table B-2 Fuel Pump and Its Circuit
Check 6- 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B-3 Fuel Pressure Check 6-100. . . . . . . . .
Table B-4 A / C Signal Circuits Check 6-102. . . .
Table B-5 Power Steering Pressure
Switch Signal Circuit Check 6-103. . . . . . . . . . .
SPECIAL TOOL6-104 . . . . . . . . . . . . . . . . . . . . . . .
6-2 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)

6-6 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ENGINE DIAGNOSIS
GENERAL DESCRIPTION
This vehicle is equipped with an engine and emission control system which are under control of ECM (PCM).
The engine and emission control system in this vehicle are controlled by ECM (PCM). ECM (PCM) has an On-
Board Diagnostic system which detects a malfunction in this system and abnormality of those parts that influence
the engine exhaust emission. When diagnosing engine troubles, be sure to have full understanding of the outline
of “On-Board Diagnostic System” and each item in “Precaution in Diagnosing Trouble” and execute diagnosis ac-
cording to “ENGINE DIAGNOSTIC FLOW TABLE”.
There is a close relationship between the engine mechanical, engine cooling system, ignition system, exhaust sys-
tem, etc. and the engine and emission control system in their structure and operation. In case of an engine trouble,
even when the malfunction indicator lamp (MIL) doesn’t turn ON, it should be diagnosed according to this flow table.
ON-BOARD DIAGNOSTIC SYSTEM
ECM (PCM) in this vehicle has following functions.

When the ignition switch is turned ON with the engine at a stop,
malfunction indicator lamp (MIL) (1) turns ON to check the bulb
of the malfunction indicator lamp (1).

When ECM (PCM) detects a malfunction which gives an adverse
effect to vehicle emission while the engine is running, it makes the
malfunction indicator lamp (1) in the meter cluster of the instru-
ment panel turn ON or flash (flashing only when detecting a mis-
fire which can cause damage to the catalyst) and stores the mal-
function area in its memory.
(If it detects that continuously 3 driving cycles are normal after de-
tecting a malfunction, however, it makes MIL (1) turn OFF al-
though DTC stored in its memory will remain.)

As a condition for detecting a malfunction in some areas in the
system being monitored by ECM (PCM) and turning ON the mal-
function indicator lamp (1) due to that malfunction, 2 driving cycle
detection logic is adopted to prevent erroneous detection.

When a malfunction is detected, engine and driving conditions
then are stored in ECM (PCM) memory as freeze frame data. (For
the details, refer to description on Freeze frame data.)

It is possible to communicate by using not only SUZUKI scan tool
(Tech-1) (2) but also generic scan tool. (Diagnostic information
can be accessed by using a scan tool.)

An Example of Freeze Frame Data
1. Trouble Code P0102 (1st)
2. Engine Speed 782 RPM
3. Eng Cool Tmp. 80C
4. Vehicle Spd. 0 km/h
5. MAP Sensor 39 kPa
6. St. Term FT1– 0.8% Lean
7. Lg. Term FT1– 1.6% Lean
8. Fuel 1 Stat. Closed Loop
9. Fuel 2 Stat. Not used
10. Load value 25.5%
1st, 2nd or 3rd in parentheses here represents which
position in the order the malfunction is detected.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-7
Warm-up Cycle
A warm-up cycle means sufficient vehicle operation such that the
coolant temperature has risen by at least 22C (40F) from engine
starting and reaches a minimum temperature of 70C (160F).
Driving Cycle
A “Driving Cycle” consists of engine startup, driving mode where a
malfunction would be detected if present and engine shutoff.
2 Driving Cycles Detection Logic
The malfunction detected in the first driving cycle is stored in ECM
(PCM) memory (in the form of pending DTC and freeze frame data)
but the malfunction indicator lamp does not light at this time. It lights
up at the second detection of same malfunction also in the next driv-
ing cycle.
Pending DTC
Pending DTC means a DTC detected and stored temporarily at 1
driving cycle of the DTC which is detected in the 2 driving cycles
detection logic.
Freeze Frame Data
ECM (PCM) stores the engine and driving conditions (in the from
of data as shown at the left) at the moment of the detection of a mal-
function in its memory. This data is called “Freeze frame data”.
Therefore, it is possible to know engine and driving conditions (e.g.,
whether the engine was warm or not, where the vehicle was running
or stopped, where air / fuel mixture was lean or rich) when a mal-
function was detected by checking the freeze frame data. Also,
ECM (PCM) has a function to store each freeze frame data for three
different malfunctions in the order as the malfunction is detected.
Utilizing this function, it is possible to know the order of malfunctions
that have been detected. Its use is helpful when rechecking or diag-
nosing a trouble.
Priority of freeze frame data:
ECM (PCM) has 4 frames where the freeze frame data can be
stored. The first frame stores the freeze frame data of the malfunc-
tion which was detected first. However, the freeze frame data
stored in this frame is updated according to the priority described
below. (If malfunction as described in the upper square “1” below
is detected while the freeze frame data in the lower square “2” has
been stored, the freeze frame data “2” will be updated by the freeze
frame data “1”.)
PRIORITY
FREEZE FRAME DATA IN FRAME 1
1
Freeze frame data at initial detection of malfunction
among misfire detected (P0300-P0303), fuel
system too lean (P0171) and fuel system too rich
(P0172)
2Freeze frame data when a malfunction other than
those in “1” above is detected

Body ground
ECM (PCM) ground
Serial data line
(K line of ISO 9141)SUZUKI
serial data
line
6-8 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
In the 2nd through the 4th frames, the freeze frame data of each
malfunction is stored in the order as the malfunction is detected.
These data are not updated.
Shown in the table below are examples of how freeze frame data
are stored when two or more malfunctions are detected.
FRAMEFRAME 1FRAME 2FRAME 3FRAME 4FRAME
MALFUNCTION
DETECTED ORDER
FREEZE FRAME
DATA
to be updated1st FREEZE
FRAME DATA2nd FREEZE
FRAME DATA3rd FREEZE
FRAME DATA
No malfunctionNo freeze frame data
1P0400 (EGR)
detectedData at P0400
detectionData at P0400
detection––
2P0171 (Fuel
system) detectedData at P0171
detectionData at P0400
detectionData at P0171
detection–
3P0300 (Misfire)
detectedData at P0171
detectionData at P0400
detectionData at P0171
detectionData at P0300
detection
4P0301 (Misfire)
detectedData at P0171
detectionData at P0400
detectionData at P0171
detectionData at P0300
detection
Freeze frame data clearance:
The freeze frame data is cleared at the same time as clearance of
diagnostic trouble code (DTC).
Data Link Connector (DLC)
DLC (1) is in compliance with SAEJ1962 in its installation position,
the shape of connector and pin assignment.
Serial data line (K line of ISO 9141) is used for SUZUKI scan tool
(Tech-1) or generic scan tool to communicate with ECM (PCM).
SUZUKI serial data line is used for SUZUKI scan tool (Tech-1) to
communicate with ABS control module and air bay SDM.

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-9
PRECAUTION IN DIAGNOSING TROUBLE

Don’t disconnect couplers from ECM (PCM), battery cable from
battery, ECM (PCM) ground wire harness from engine or main
fuse before confirming diagnostic information (DTC, freeze frame
data, etc.) stored in ECM (PCM) memory. Such disconnection will
erase memorized information in ECM (PCM) memory.

Diagnostic information stored in ECM (PCM) memory can be
cleared as well as checked by using SUZUKI scan tool (Tech-1)
or generic scan tool. Before using scan tool, read its Operator’s
(Instruction) Manual carefully to have good understanding as to
what functions are available and how to use it.

Priorities for diagnosing troubles.
If two or more DTCs are stored, proceed to the flow table of the
DTC which has detected earliest in the order and follow the
instruction in that table.
If no instructions are given, troubleshoot diagnostic trouble codes
according to the following priorities.
1. Diagnostic trouble codes (DTCs) other than DTC P0171 /
P0172 (Fuel system too lean / too rich) and DTC P0300 /
P0301 / P0302 / P0303 (Misfire detected)
2. DTC P0171 / P0172 (Fuel system too lean / too rich)
3. DTC P0300 / P0301 / P0302 / P0303 (Misfire detected)

Be sure to read “Precautions for Electrical Circuit Service” in Sec-
tion 0A before inspection and observe what is written there.

ECM (PCM) Replacement
When substituting a known-good ECM (PCM), check for following
conditions. Neglecting this check may cause damage to a known-
good ECM (PCM).
–Resistance value of all relays, actuators is as specified respec-
tively.
–MAP sensor and TP sensor are in good condition and none of
power circuits of these sensors is shorted to ground.