etc SUZUKI SWIFT 2007 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-1
Engine
Engine General Information and Diagnosis
Precautions
Precautions on Engine ServiceS7RS0B1100001
CAUTION!
The following information on engine service
should be noted carefully, as it is important in
preventing damage, and in contributing to
reliable engine performance.

• When raising or supporting engine for any reason, do
not use a jack under oil pan. Due to small clearance
between oil pan and oil pump strainer, jacking against
oil pan may cause it to be bent against strainer,
resulting in damaged oil pick-up unit.
• It should be kept in mind , while working on engine,
that 12-volt electrical syste m is capable of violent and
damaging short circuits.
When performing any work where electrical terminals
can be grounded, ground cable of the battery should
be disconnected at battery.
• Any time the air cleaner, throttle body or intake manifold is removed, the intake opening should be
covered. This will protect against accidental entrance
of foreign material which could follow intake passage
into cylinder and cause extensive damage when
engine is started.
Precaution on On-Board Diagnostic (OBD)
System
S7RS0B1100005
There are two types of On -Board Diagnostic (OBD)
system, Euro OBD system and non-Euro-OBD system,
depending on the vehicle specification.
As the diagnosis function is different between these two
types, be sure to fully understand the OBD system
referring to “On-Board Diagnostic System Description”.
OBD System Summary Table
Precautions in Diagnosing TroubleS7RS0B1100002
NOTE
There are two types of OBD system
depending on the vehicle specification.
For details, refer to “Precaution on On-Board
Diagnostic (OBD) System”.

• Don’t disconnect couplers from ECM, battery cable
from battery, ECM ground wire harness from engine
or main fuse before confirming diagnostic information
(DTC, freeze frame data, etc.) stored in ECM memory.
Such disconnection will erase memorized information
in ECM memory.
• Diagnostic information stored in ECM memory can be cleared as well as checke d by using SUZUKI scan
tool or OBD 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.
For Euro OBD model it is indistinguishable which
module turns on MIL because not only ECM but also
TCM (A/T model) turns on MIL (For details of on-
board diagnostic system for A/T model, refer to “On-
Board Diagnostic System Description in Section 5A”).
Therefore, check both ECM and TCM (A/T model) for
DTC when MIL lights on.
When checking ECM for DTC, keep in mind that DTC
is displayed on the scan tool as follows depending on
the scan tool used.
– SUZUKI scan tool displays DTC detected by ECM.
– OBD generic scan tool displays DTC detected by each of ECM and TCM (A/T model) simultaneously.
• Priorities for diagnosing troubles If two or more DTCs are stored, proceed to the DTC
flow which has been detected earliest in the order and
follow the instructi on in that flow.
If no instructions are given, troubleshoot DTCs
according to the following priorities.
a. DTCs other than DTC P0171 / P0172 (Fuel system too lean / too rich), DTC P0300 / P0301 /
P0302 / P0303 / P0304 (Misfire detected) and
DTC P0401 / P0402 (EGR flow malfunction)
b. DTC P0171 / P0172 (Fuel system too lean / too rich) and DTC P0401 / P0402 (EGR flow
malfunction)
c. DTC P0300 / P0301 / P0302 / P0303 / P0304 (Misfire detected)
Euro OBD
model Non-Euro-OBD
model
Quantity of DTC
related to engine
control Approx. 80 Approx. 60
Freeze frame
data Available Not available
SUZUKI scan
tool Available Available
OBD generic
scan tool Available Not available

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-3
• The four cylinders of the engine are identified by numbers; No.1 (1), No.2 (2 ), No.3 (3) and No.4 (4)
counted from crankshaft pulley side to flywheel side.
Engine Diagnosis General DescriptionS7RS0B1101002
NOTE
There are two types of OBD system
depending on the vehicle specification.
For details, refer to “Precaution on On-Board
Diagnostic (OBD) System”.

This vehicle is equipped with an engine and emission
control system which are under control of ECM.
The engine and emission control system in this vehicle
are controlled by ECM. ECM 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 Description” and each
item in “Precautions in Diagnosing Trouble” and execute
diagnosis according to “Engine and Emission Control
System Check”.
There is a close relationship between the engine
mechanical, engine cooling system, ignition system,
exhaust system, 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 “Engine and Emission Control System
Check”.
On-Board Diagnostic System DescriptionS7RS0B1101003
NOTE
There are two types of OBD system
depending on the vehicle specification.
For details, refer to “Precaution on On-Board
Diagnostic (OBD) System”.

Euro OBD Model
ECM in this vehicle has the 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 circuit of the malfunction indicator
lamp (1). • When ECM 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 inst rument panel turn ON or
flash (flashing only when detecting a misfire which
can cause damage to the catalyst) and stores the
malfunction area in its memory.
(If it detects that contin uously 3 driving cycles are
normal after detecting a malfunction, however, it
makes MIL (1) turn OFF although DTC stored in its
memory will remain.)
• As a condition for detecting a malfunction in some areas in the system being monitored by ECM and
turning ON the malfunction 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 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 (2) but also OBD generic scan tool.
(Diagnostic information can be accessed by using a
scan tool.)
Warm-Up Cycle
A warm-up cycle means sufficie nt vehicle operation such
that the coolant temperature has risen by at least 22 °C
(40 °F) from engine starting and reaches a minimum
temperature of 70 °C (160 ° F).
1
23 4
I3RM0A110001-01
3. DLC
2
3
1
I4RS0B110001-01

Downloaded from www.Manualslib.com manuals search engine 1A-6 Engine General Information and Diagnosis:
For information about the following items, refer to “Euro
OBD Model: ”.
• Warm-up cycle
• Driving cycle
• 2 driving cycle detection logic
• Pending DTC
Data Link Connector (DLC)S7RS0B1101013
DLC (1) is in compliance with SAE J1962 in the shape of
connector and pin assignment.
OBD serial data line (3) (K line of ISO 9141) is used for
SUZUKI scan tool or OBD generic scan tool to
communicate with ECM, Air bag SDM, HVAC control
module (auto A/C model), immobilizer control module (in
ECM), BCM (Body electrical Control Module), TCM
(Transmission Cont rol Module (A/T model)) and ABS/
ESP ® control module.
Engine and Emission Control System
Description
S7RS0B1101004
The engine and emission control system is divided into 4
major sub-systems: air in take system, fuel delivery
system, electronic control sy stem and emission control
system.
Air intake system includes air cleaner, throttle body, IAC
valve and intake manifold.
Fuel delivery system includes fuel pump, delivery pipe,
etc.
Electronic control system incl udes ECM, various sensors
and controlled devices.
Emission control system includes EGR, EVAP and PCV
system.
2. B + (Unswitched vehicle battery positive)
4. ECM ground (Signal ground)
5. Vehicle body ground (Chassis ground)
2
345
1
910111213141516
12345678
1I4RS0B110002-01

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-11
Generator Control System DescriptionS7RS0B1101010
Generator Control System consists of a generator (1), electric load current sensor (7) located in the main fuse box (4)
and ECM (5).
ECM controls generated electricity (adjusting voltage of IC regulator (2)) so that it is suitable for the engine and electric
load conditions. When the electric load increases quickly, generation load of the generator increases quickly and
causes idling to change. To prevent this, ECM makes generated electricity volume vary gradually to stabilize idling.
Also, it reduces the engine load caused by temporary incr ease in electricity generation to cope with the engine
condition (such as when accelerating).
Operation
ECM controls the generated voltage of the generator using “C” terminal (generator control terminal) duty, based on
following information.
• Engine condition (ECT, vehicle speed, engine speed, TP, etc.) (9)
• Battery voltage (ECM backup power voltage) (10)
• Electric load condition (blower motor, rear defogger, head lights, radiator fan, A/C, etc.) (11)
• “FR” terminal output (field coil (3) cont rol duty) which indicates the operation rate (electricity generation condition) of
the generator.
Then the generator uses “C” terminal duty to regulate the adju sting voltage of the IC regulator with the field coil control
duty so as to control its generated voltage (“B” terminal output voltage).
(For more information of the generated voltage, refer to “Charging System Specifications in Section 1J”.)
Furthermore, the generation condition of the generator is co ntrolled to the optimum level by the electric load current
sensor (7) which detects the electrical load condition (cur rent consumption) linearly even when a sudden electrical
load variation occurs and thus the engine load is reduced.
B
IG
L
C
E
6
2
3
FR
5
12 13
14
1IG1
7
4
8
11
10 9
CMO
FCD
GCD
I6RW0H110005-01
6. Ignition switch
12. BCM 14. CAN driver
8. Battery 13. Combination meter

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-25
Step 2: DTC / Freeze Frame Data Check, Record and
Clearance
First, check DTC (including pending DTC), referring to
“DTC Check”. If DTC is indicated, print it and freeze
frame data or write them down and then clear them by
referring to “DTC Clearance”. DTC indicates malfunction
that occurred in the system but does not indicate
whether it exists now or it occurred in the past and the
normal condition has been restored now. To check which
case applies, check the sy mptom in question according
to Step 5 and recheck DTC according to Step 6 and 7.
Attempt to diagnose a trouble based on DTC in this step
only or failure to clear the DTC in this step will lead to
incorrect diagnosis, trouble diagnosis of a normal circuit
or difficulty in troubleshooting.
Step 3 and 4: Visual Inspection
As a preliminary step, be sure to perform visual check of
the items that support proper function of the engine
referring to “Visual Inspection”.
Step 5: Trouble Symptom Confirmation
Based on information obtained in “Step 1: Customer
Complaint Analysis: ” and “Step 2: DTC / Freeze Frame
Data Check, Record and Clearance: ”, confirm trouble
symptoms. Also, reconfirm DTC according to “DTC
Confirmation Procedure” described in each DTC diag.
flow.
Step 6 and 7: Rechecking and Record of DTC /
Freeze Frame Data
Refer to “DTC Check” for checking procedure.
Step 8: Engine Basic Inspection and Engine
Symptom Diagnosis
Perform basic engine check according to “Engine Basic
Inspection” first. When the end of the flow has been
reached, check the parts of the system suspected as a
possible cause referring to “Engine Symptom Diagnosis”
and based on symptoms appearing on the vehicle
(symptoms obtained through steps of customer
complaint analysis, trouble symptom confirmation and/or
basic engine check) and repair or replace faulty parts, if
any.
Step 9: Troubleshooting for DTC (See each DTC
Diag. Flow)
Based on the DTC indicated in Step 6 or 7 and referring
to the applicable DTC diag. flow, locate the cause of the
trouble, namely in a sensor, switch, wire harness,
connector, actuator, ECM or other part and repair or
replace faulty parts. Step 10: Intermittent Problems Check
Check parts where an intermit
tent trouble is easy to
occur (e.g., wire harness, connector, etc.), referring to
“Intermittent and Poor Connec tion Inspection in Section
00” and related circuit of DTC recorded in Step 2.
Step 11: Final Confirmation Test
Confirm that the problem symptom has gone and the
engine is free from any abnormal conditions. If what has
been repaired is re lated to the DTC, clear the DTC once,
perform DTC confirmation procedure and confirm that no
DTC is indicated.
Malfunction Indicator Lamp (MIL) CheckS7RS0B1104002
1) Turn ON ignition switch (with engine at stop) and check that MIL (1) lights.
If MIL does not light up (or MIL dims) but engine can
be starting, go to “MIL Does Not Come ON with
Ignition Switch ON and Engine Stop (but Engine Can
Be Started)” for troubleshooting.
If MIL does not light with ignition switch ON and
engine does not start though it is cranked up, go to
“ECM Power and Ground Circuit Check”.
2) Start engine and check that MIL turns OFF. If MIL remains ON and no DTC is stored in ECM, go
to “Malfunction Indicator Lamp Remains ON after
Engine Starts” for troubleshooting.
1
I4RS0A110012-01

Downloaded from www.Manualslib.com manuals search engine 1A-36 Engine General Information and Diagnosis:
O2S B1 S1 ACT (HEATED OXYGEN SENSOR-1,
ACTIVE / INACTIVE)
This parameter indicates activation condition of HO2S-1.
ACTIVE: Activating
INACTIVE: warming up or at stop
O2S SENSOR B1 S2 (HEATED OXYGEN SENSOR-2,
V)
It indicates output voltage of HO2S-2 installed on
exhaust pipe (post-catalyst). It is used to detect catalyst
deterioration.
O2S B1 S2 ACT (HEATED OXYGEN SENSOR-2,
ACTIVE / INACTIVE)
This parameter indicates acti vation condition of HO2S-2.
ACTIVE: Activating
INACTIVE: warming up or at stop
FUEL SYSTEM (FUEL SYSTEM STATUS)
Air/fuel ratio feedback loop status displayed as one of
the followings.
OPEN: Open-loop has not yet satisfied conditions to go
closed loop.
CLOSED: Closed-loop using oxygen sensor(s) as
feedback for fuel control.
OPEN-DRIVE COND: Open-loop due to driving
conditions (Power enrichment, etc.).
OPEN SYS FAULT: Open-loop due to detected system
fault.
MAP (MANIFOLD ABSOLUTE PRESSURE, in.Hg,
kPa)
This value indicates how much correction is necessary
to keep the air/fuel mixture stoichiometrical.
It is detected by manifold absolute pressure sensor.
BAROMETRIC PRESS (kPa, in.Hg)
This parameter represents a measurement of barometric
air pressure and is used for al titude correction of the fuel
injection quantity and IAC valve control.
STEP EGR FLOW DUTY (%)
This parameter indicates opening rate of EGR valve
which controls the amount of EGR flow.
FUEL CUT (ON/OFF)
ON: Fuel being cut (output signal to injector is stopped)
OFF: Fuel not being cut
A/C PRESSURE (A/C REFRIGERANT ABSOLUTE
PRESSURE, kPa)
This parameter indicates A/C refrigerant absolute
pressure calculated by ECM.
CLOSED THROTTLE PO S (CLOSED THROTTLE
POSITION, ON/OFF)
This parameter reads ON wh en throttle valve is fully
closed, or OFF when it is not fully closed. CANIST PRG DUTY (EVAP CANISTER PURGE FLOW
DUTY, %)
This parameter indicates valve ON (valve open) time
rate within a certain set cycle of EVAP canister purge
valve which controls the amount of EVAP purge.
IGNITION ADVANCE (IGNITION TIMING ADVANCE
FOR NO.1 CYLINDER,
°)
Ignition timing of No.1 cylinder is commanded by ECM.
The actual ignition timing should be checked by using
the timing light.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage
inputted from main relay to ECM.
FUEL PUMP (ON/OFF)
ON is displayed when ECM activates the fuel pump via
the fuel pump relay switch.
ELECTRIC LOAD (ON/OFF)
ON: Headlight or small light ON signal inputted.
OFF: Above electric loads all turned OFF.
BRAKE SW (ON/OFF)
This parameter indicates the state of the brake switch.
RADIATOR COOLING FAN (RADIATOR COOLING
FAN CONTROL RELAY, ON/OFF)
ON: Command for radiator cooling fan control relay
operation being output.
OFF: Command for relay operation not being output.
BLOWER FAN (ON/OFF)
This parameter indicates the state of the blower fan
motor switch.
A/C SWITCH (ON/OFF)
ON: Command for A/C operatio n being output from ECM
to HVAC.
OFF: Command for A/C oper ation not being output.
A/C COMP RELAY (A/C COMPRESSOR RELAY, ON/
OFF)
This parameter indicates the state of the A/C switch.
VEHICLE SPEED (km/h, mph)
It is computed based on pulse signals from vehicle
speed sensor.
VVT GAP (TARGET-ACTUAL POSITION, °)
It is calculated using the formula: target valve timing
advance – actual valve timing advance.
TP SENSOR 1 VOLT (THROTTLE POSITION SENSOR
(MAIN) OUTPUT VOLTAGE, V)
The TP sensor (main) reading provides throttle valve
opening information in the form of voltage.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-43
Poor gasoline mileageLeaks or loose connection of high-
tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Faulty spark plug (improper gap, heavy
deposits and burned electrodes, etc.) “Spark Plug Inspection in Section 1H”
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
High idle speed Condition “Improper engine idling or engine
fails to idle”
Poor performance of ECT sensor or
MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty fuel injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Low compression “Compression Check in Section 1D”
Poor valve seating “Valves and Valve Guides Inspection in
Section 1D”
Dragging brakes Condition “Dragging brakes” in “Brakes
Symptom Diagnosis in Section 4A”
Slipping clutch Condition “Slipping clutch” in “Clutch System
Symptom Diagnosis in Section 5C”
Thermostat out of order “Thermostat Inspection in Section 1F”
Improper tire pressure “Tires Description in Section 2D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Excessive engine oil
consumption – Oil
leakage Blown cylinder head gasket
“Cylinder Head Inspection in Section 1D”
Leaky camshaft oil seals “Camshaft, Tappet and Shim Inspection in
Section 1D”
Excessive engine oil
consumption – Oil
entering combustion
chamber Sticky piston ring
“Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn piston and cylinder “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Worn piston ring groove and ring “Cylinders, Pistons and Piston Rings
Inspection in Section 1D”
Improper location of piston ring gap “Pistons, Piston Rings, Connecting Rods and
Cylinders Disassembly and Assembly in
Section 1D”
Worn or damaged valve stem seal “Valves and Valve Guides Inspection in
Section 1D”
Worn valve stem “Valves and Valve Guides Inspection in
Section 1D”
Condition Possible cause Correction / Reference Item

Downloaded from www.Manualslib.com manuals search engine 1A-44 Engine General Information and Diagnosis:
Engine hesitates –
Momentary lack of
response as accelerator
is depressed. Can occur
at all vehicle speeds.
Usually most severe when
first trying to make
vehicle move, as from a
stop sign.Spark plug faulty
“Spark Plug Inspection in Section 1H”
Leaky high-tension cord “High-Tension Cord Inspection in Section 1H”
Fuel pressure out of specification “Fuel Pressure Check”
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of ECT sensor or
MAF sensor “ECT Sensor Inspection in Section 1C” or
“MAF and IAT Sensor Inspection in Section
1C”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty fuel injector “Fuel Injector Circuit Check”
Faulty ECM
Engine overheating Condition “Engine overheating”
Low compression “Compression Check in Section 1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Surge – Engine power
variation under steady
throttle or cruise. Feels
like vehicle speeds up
and down with no change
in accelerator pedal. Leaky or loosely connected high-tension
cord
“High-Tension Cord Removal and Installation
in Section 1H”
Faulty spark plug (excess carbon
deposits, improper gap, burned
electrodes, etc.) “Spark Plug Inspection in Section 1H”
Variable fuel pressure “Fuel Pressure Check”
Kinky or damaged fuel hose and lines
Faulty fuel pump (clogged fuel filter)
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of MAF sensor “MAF and IAT Sensor Inspection in Section
1C”
Faulty fuel injector “Fuel Injector Circuit Check”
Faulty electric throttle body assembly “Electric Throttle Body Assembly On-Vehicle
Inspection in Section 1C”
Faulty APP sensor assembly “APP Sensor Assembly Inspection in Section
1C”
Faulty ECM
Excessive detonation –
Engine makes
continuously sharp
metallic knocks that
change with throttle
opening. Sounds like pop
corn popping. Faulty spark plug
“Spark Plug Inspection in Section 1H”
Loose connection of high-tension cord “High-Tension Cord Removal and Installation
in Section 1H”
Engine overheating Condition “Engine overheating”
Clogged fuel filter (faulty fuel pump) or
fuel lines “Fuel Pressure Check” or “Fuel Pump and Its
Circuit Check”
Air drawn in through intake manifold or
throttle body gasket
Malfunctioning EGR valve “EGR Valve Inspection in Section 1B”
Poor performance of knock sensor, ECT
sensor or MAF sensor “DTC P0327 / P0328: Knock Sensor 1 Circuit
Low / High”, “ECT Sensor Inspection in
Section 1C” or “MAF and IAT Sensor
Inspection in Section 1C”
Faulty fuel injector(s) “Fuel Injector Circuit Check”
Faulty ECM
Excessive combustion chamber
deposits “Cylinders, Pistons and Piston Rings
Inspection in Section 1D” and/or “Piston Pins
and Connecting Rods In
spection in Section
1D”
Camshaft position control (VVT) system
out of order “Oil Control Valve Inspection in Section 1D”
Condition Possible cause Correction / Reference Item

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-77
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 by 2 persons, a driver and tester, on a level road.

NOTE
Check to make sure that following conditions ar e satisfied when using this “DTC Confirmation
Procedure”.
• Intake air temperature at engine start: –10 °C (14 ° F) to 80 °C (176 °F)
• Intake air temperature: –10 °C (14 °F) to 70 °C (158 °F)
• Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)

1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch, clear DTC.
3) Start engine.
4) Drive vehicle at 40 mph (60 km/h) or higher for 20 min. or more.
5) Stop vehicle.
6) Check DTC and pending DTC.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

Step Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 DTC check
1) With ignition switch turned OFF, install scan tool to DLC.
2) Turn ON ignition switch and check DTC with scan tool.
Is DTC P0118 displayed? Go to “DTC P0118:
Engine Coolant
Temperature Circuit
High”.
Go to Step 3.
3 Engine coolant temp. check
1) Turn ON ignition switch and check engine coolant temp.
displayed on scan tool.
2) Warm up engine to normal operating temp. and check engine coolant temp. displayed on scan tool.
Does engine coolant te mp. vary more than 1
°C (1 °F) and
rise higher than 70
°C (158 °F)? Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection in Section
00”.
Go to Step 4.
4 Thermostat check
Is there a symptom due to thermostat remaining open (it
takes a long time before vehicle heater becomes effective or
before engine is warmed to normal operating temp., etc.)? Check thermostat
referring to “Thermostat
Inspection in Section
1F”.
Go to Step 5.

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-143
DTC P1510: ECM Back-Up Power Supply MalfunctionS7RS0B1104060
Wiring Diagram
Circuit Description
Battery voltage is supplied so that DTC memory, values for engine control learned by ECM, etc. are kept in ECM even
when the ignition switch is turned OFF.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure
1) Connect scan tool to DLC with ignition switch turned OFF.
2) Turn ON ignition switch and clear DTC using scan tool and run engine at idle speed for 1 min.
3) Check DTC.
E23 C37
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
34
1819
567
1011
17
20
47 46
495051
2122
52 16
25 9
24
14
29
55
57 54 53
59
60 58 2
262728
15
30
56 4832 31
34353637
40
42 39 38
44
45 43 41 331
1213
238
WHT/REDWHT80A
50A
3
2 1
E23-2
I4RS0A110051-01
1. ECM
2. “RADIO” fuse 3. Main fuse box
DTC detecting condition Trouble area
Back-up power circuit voltage is less than 70% battery voltage for
5 seconds continuously while engine is running.
(1 driving cycle detection logic) Battery voltage supply circuit