2008 SUZUKI SWIFT Speed sensor

Downloaded from www.Manualslib.com manuals search engine 1A-30 Engine General Information and Diagnosis:
)
U *P0617 Starter relay circuit high Starter signal is high voltage for specified time while
engine is running. 2 driving
cycles
) P0620 Generator control circuit Battery voltage is higher than specification even through
generator control is maximum regulation, or battery
voltage is lower than specification even through generator
control is minimum regulation
and electric load is less
than 15 A. —
) P0625 Generator field/F terminal
circuit low Generator field coil duty is
0% (high voltage) for more
than specified time even through generator control is
minimum regulation. —
) P0626 Generator field/F terminal
circuit high Generator field coil duty is
100% (low voltage) for more
than specified time even through generator control is
maximum regulation, or generator field coil duty is 100%
(low voltage) when engine is starting. —
) P1501 Electric load current sensor
circuit low Electric load current is lowe
r than specified value (electric
load current sensor voltage is higher than specified
value). —
) P1502 Electric load current sensor
circuit high Electric load current is higher than specified value
(electric load current sens
or voltage is lower than
specified value). —
)
U *P1510 ECM backup power supply
malfunction Backup power voltage is out of
specification after starting
engine. 1 driving
cycle
) † P1603 TCM trouble code detected When ECM receives a trouble code from TCM, which
indicates that some problem occurred in sensor circuits
and its calculated values used for operations such as idle
speed control, engine power control and so on by TCM,
this DTC is detected by ECM. —
) *P1674 CAN communication (buss off
error) Transmission error that
is inconsistent between
transmission data and transmission monitor (CAN bus
monitor) data is detected more than 7 times continuously. 1 driving
cycle
)
† *P1676 CAN communication (reception
error for TCM) Reception error of communication data for TCM is
detected for longer than specified time continuously. 1 driving
cycle
) P1678 CAN communication (reception
error for BCM) Reception error of communication data for BCM is
detected for longer than specified time continuously.
—
) *P1685 CAN communication (reception
error for ABS/ESP
® control
module) Reception error of communication data for ABS/ESP
®
co

ntrol module is detected for longer than specified time
continuously. 1 driving
cycle
) *P2101 Throttle actuator control motor
circuit range/performance Monitor signal of throttle actuator output (duty output) is
inconsistent with throttle actuator control command. 1 driving
cycle
) *P2102 Throttle actuator control motor
circuit low Power supply voltage of throttle actuator control circuit is
lower than specification even
if throttle actuator control
relay turned on. 1 driving
cycle
) *P2103 Throttle actuator control motor
circuit high Power supply voltage of throttle actuator control circuit is
higher than specification even if throttle actuator control
relay turned off. 1 driving
cycle
) *P2111 Throttle actuator control
system – stuck open Throttle valve default opening is greater than specified
value from complementary closed position when
diagnosing throttle valve at ignition switch turned OFF. 1 driving
cycle
) *P2112 Throttle actuator control
system – stuck closed Throttle valve default opening is smaller than specified
value from complementary closed position when
diagnosing throttle valve at ignition switch turned OFF. 1 driving
cycle
) *P2119 Throttle actuator control throttle
body range/performance Difference between actual throttle valve opening angle
and opening angle calculated by ECM is more than
specification. 1 driving
cycle
) *P2122 Throttle/pedal position sensor/
switch “D” (main) circuit low
input Output voltage of APP sensor (main) is lower than
specification.
1 driving
cycle
DTC No. Detecting item
Detecting condition
(DTC will set when detecting:) MIL

Downloaded from www.Manualslib.com manuals search engine 1A-32 Engine General Information and Diagnosis:
) P0117 Engine coolant temperature circuit low • EC M controls actuators assuming that engine
coolant temperature is 80 °C (176 °F).
• ECM operates radiator cooling fan.
)
P0118 Engine coolant temperature circuit high
) P0122 Throttle/pedal position sensor/switch/“A” (main)
circuit low • ECM turns off throttle actuator control relay and
throttle valve is fixed at the specified opening from
its completely closed position (default opening).
For details, refer to “Description of Electric
Throttle Body System”.
• ECM controls fuel cut at specified engine speed.
• ECM stops air/fuel ratio control.
)
P0123 Throttle/pedal position sensor/switch/“A” (main)
circuit high
) P0222 Throttle/pedal position sensor/switch/“B” (sub)
circuit low
) P0223 Throttle/pedal position sensor/switch/“B” (sub)
circuit high
) P0131 O2 sensor (HO2S) circuit low voltage (Sensor-1)
ECM stops air/fuel ratio control.
)
P0132 O2 sensor (HO2S) circuit high voltage (Sensor-1)
) P0134 O2 sensor (HO2S) circuit no activity detected
(Sensor-1)
) P0335 Crankshaft position sensor “A” circuit • Ignition timing is fixed.
• ECM changes injection control system from
sequential injection to simultaneous one.
) P0340 Camshaft position sensor “A” circuit ECM changes injection
control system from
sequential injection to simultaneous one.
) P0500 Vehicle speed sensor “A” • ECM controls actuators assuming that vehicle
speed is 0 km/h (0 mile/h).
• ECM stops IAC feedback control.
) P2101 Throttle actuator control motor circuit range /
performance • ECM turns off throttle actuator control relay and
throttle valve is fixed at the specified opening from
its completely closed position (default opening).
For details, refer to “Description of Electric
Throttle Body System”.
• ECM controls fuel cut at specified engine speed.
• ECM stops air/fuel ratio control.
)
P2102 Throttle actuator control motor circuit low
) P2103 Throttle actuator control motor circuit high ECM controls fuel cut at specified engine speed.
) P2111 Throttle actuator control system – stuck open • EC M turns off throttle actuator control relay and
throttle valve is fixed at the specified opening from
its completely closed position (default opening).
For details, refer to “Description of Electric
Throttle Body System”.
• ECM controls fuel cut at specified engine speed.
• ECM stops air/fuel ratio control.
)
P2112 Throttle actuator control system – stuck closed
) P2119 Throttle actuator control throttle body range /
performance • ECM turns off throttle actuator control relay and
throttle valve is fixed at the specified opening from
its completely closed position (default opening).
For details, refer to “Description of Electric
Throttle Body System”.
• ECM controls fuel cut at specified engine speed.
DTC No.
Detected item Fail-safe operation

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-33
Scan Tool DataS7RS0B1104007
As the data values are standard values estimated on the basis of values obtained from the normally operating vehicles
by using a scan tool, use them as re ference values. Even when the vehicle is in good condition, there may be cases
where the checked value does not fall within each specified data range. Therefore, judgment as abnormal should not
be made by checking with these data alone.
Also, conditions that can be checked by the scan tool are those detected by ECM and output from ECM as commands
and there may be cases where the engine or actuator is not operating (in the condition) as indicated by the scan tool.
Be sure to use the timing light to check the ignition timing.
NOTE
• There are two types of OBD system depending on the vehicle specification.
For details, refer to “Precaution on On-Board Diagnostic (OBD) System”.
• With the generic scan tool, only star (*) marked data in the following table can be read.
• When checking the data with the engine running at idle or racing, be sure to shift M/T gear to the neutral position and A/T gear to the “Park” position and pull the parking brake fully. Also, if nothing
or “no load” is indicated, turn O FF A/C (if equipped with A/C), all electric loads, P/S and all the other
necessary switches.

) P2122 Throttle/pedal position sensor/switch/“D” (main)
circuit low input
• ECM turns off throttle actuator control relay and throttle valve is fixed at the specified opening from
its completely closed position (default opening).
For details, refer to “Description of Electric
Throttle Body System”.
• ECM controls fuel cut at specified engine speed.
• ECM stops air/fuel ratio control.
)
P2123 Throttle/pedal position sensor/switch/“D” (main)
circuit high input
) P2127 Throttle/pedal position sensor/switch/“E” (sub)
circuit low input
) P2128 Throttle/pedal position sensor/switch/“E” (sub)
circuit high input
) P2135 Throttle/pedal position sensor/switch/“A”/“B”
(main) / (sub) voltage correction
) P2138 Throttle pedal position sensor/switch “D”/“E”
(main) / (sub) voltage correlation
) P2227 Barometric pressure sensor performance problem ECM controls actuators assuming that barometric
pressure is 101.33 kPa (762 mmHg).
DTC No. Detected item Fail-safe operation
Scan tool data
Vehicle condition Normal condition /
reference values
* ) COOLANT TEMP At specified idle speed after warming up 80 – 100 °C, 176 – 212 °F
* ) INTAKE AIR TEMP. At specifie d idle speed after warming up –5
°C (23 °F) + environmental
temp. to 40 °C (104 °F) +
environmental temp.
* ) ENGINE SPEED It idling with no load after warming upDesired idle speed ± 50 rpm
) INJ PULSE WIDTH At specified idle speed with no load after warming up
2.0 – 4.0 msec.
At 2500 r/min. with no load after warming up 2.0 – 3.6 msec.
) DESIRED IDLE It idling with radiator cooling fan stopped and all electrical
parts turned OFF after warming up, M/T at neutral 700 rpm
* ) SHORT FT B1 At specified idle speed after warming up –20 – +20%
* ) LONG FT B1 At specified idle speed after warming up –20 – +20%
) TOTAL FUEL TRIM
B1 At specified idle speed after warming up
–35 – +35%
* ) MAF At specified idle speed wit
h no load after warming up 1.0 – 4.0 g/s 0.14 – 0.52 lb/
min.
At 2500 r/min. with no load after warming up 4.0 – 12.0 g/s 0.53 – 1.58 lb/
min.
* ) CALC LOAD At specified idle speed with no load after warming up
18 – 28%
At 2500 r/min. with no load after warming up 13 – 23%
* )
THROTTLE
POSITION Ignition switch ON /
warmed up engine
stoppedAccelerator pedal released
0 – 5%
Accelerator pedal depressed
fully 90 – 100%

Downloaded from www.Manualslib.com manuals search engine 1A-34 Engine General Information and Diagnosis:
*) O2S B1 S1 At specified idle speed after warming up 0.1 – 0.95 V
) O2S B1 S1 ACT At specified id le speed after warming up ACTIVE
* ) O2S B1 S2 At 2000 r/min. for 3 min. or longer after warming up. 0.1 – 0.95 V
) O2S B1 S2 ACT At specified id le speed after warming up ACTIVE
* ) FUEL SYSTEM B1 At specif ied idle speed after warming up CLSD (closed loop)
* ) MAP At specified idle speed with no load after warming up 24 – 38 kPa, 7.1 – 11.2 in.Hg
) BAROMETRIC
PRES —Barometric pressure is
displayed
) STEP EGR FLOW
DUTY At specified idle speed after warming up 0%
) FUEL CUT Engine at fuel cut condition ON
Engine at other than fuel cut condition OFF
) A/C PRESSURE Engine running A/C ON (A/C is operating) at
ambient temperature: 30
°C (86
° F) and humidity: 50% 1350 – 1650 kPa For more
details, refer to pressure of
high pressure gage under “A/C System Performance
Inspection in Section 7B” or “A/C Refrigerant Pressure Sensor and Its Circuit
Inspection in Section 7B”.
A/C OFF (A/C is not operating)
at ambient temperature: 30 ° C
(86 °F) and engine coolant
temperature: 90 – 100 °C (194 –
212 °F) 600 – 1000 kPa After longer
than 10 min from A/C switch turned off
) CLOSED
THROTTLE POS Throttle valve at idle position ON
Throttle valve opens larger than idle position OFF
) CANIST PRG DUTY At specified idle speed after warming up 0%
* ) IGNITION ADVANCE At specified idle s peed with no load after warming up 3 – 13 ° BTDC
) BATTERY VOLTAGE Ignition switch ON / engine at stop 10 – 14 V
) FUEL PUMP Within 2 seconds after ignition switch ON or engine
running
ON
Engine at stop with ignition switch ON OFF
) ELECTRIC LOAD Ignition switch ON / Headligh
t, small light, all turned OFF OFF
Ignition switch ON / Headli ght, small light, turned ON ON
) BRAKE SWITCH Igni tion switch ONBrake pedal is released OFF
Brake pedal is depressed ON
) RADIATOR FAN Ignition switch ON Engin
e coolant temp.: Lower
than 95 °C (203 °F) OFF
Engine coolant temp.: 97.5 °C
(208 °F) or higher ON
) BLOWER FAN Ignition switch ON Blower fan switch: 3rd speed
position or more
ON
Blower fan switch: under 2nd
speed position OFF
) A/C SWITCH Engine running after warming up, A/C not operating
OFF
Engine running after warming up, A/C operating ON
) A/C COMP RELAY Engine running A/C switch and blower motor
switch turned ON
ON
A/C switch and blower motor
switch turned OFF OFF
* ) VEHICLE SPEED At stop 0 km/h (0 mph)
) VVT GAP At specified idle speed after warming up 0 – 3°
) TP SENSOR 1 VOLT Ignition switch ON after
warmed up engine Accelerator pedal released
0.6 – 1.0 V
Accelerator pedal depressed
fully 3.37 – 4.55 V
Scan tool data
Vehicle condition Normal condition /
reference values

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-35
Scan Tool Data Definitions
COOLANT TEMP (ENGINE COOLANT
TEMPERATURE, °C, °F)
It is detected by engine coolant temp. sensor.
INTAKE AIR TEMP. ( °C, °F)
It is detected by intake air temp. sensor.
ENGINE SPEED (rpm)
It is computed by reference pulses from the camshaft
position sensor.
INJ PULSE WIDTH (FUEL INJECTION PULSE WIDTH,
msec.)
This parameter indicates time of the injector drive (valve
opening) pulse which is output from ECM (but injector
drive time of NO.1 cylinder fo r multiport fuel injection).
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter
which indicates the ECM requested idle. If the engine is
not running, this number is not valid.
SHORT FT B1 (SHORT TERM FUEL TRIM, %)
Short term fuel trim valu e represents short term
corrections to the air/fuel mixture computation. A value
of 0 indicates no correction, a value greater than 0
means an enrichment correction, and a value less than 0
implies an enleanment correction. LONG FT B1 (LONG TERM FUEL TRIM, %)
Long term fuel trim value represents long term
corrections to the air/fuel mixture computation. A value
of 0 indicates no correction, a value greater than 0
means an enrichment correction, and a value less than 0
implies an enleanment correction.
TOTAL FUEL TRIM B1 (%)
The value of Total Fuel Trim is obtained by calculating
based on values of Short Term Fuel Trim and Long Term
Fuel Trim. This value indica
tes how much correction is
necessary to keep the air/fuel mixture stoichiometrical.
MAF (MASS AIR FLOW RATE, g/s, lb/min.)
It represents total mass of air entering intake manifold
which is measured by mass air flow sensor.
CALC LOAD (CALCULATED LOAD VALUE, %)
Engine load displayed as a percentage of maximum
possible load. Value is calculated mathematically using
the formula: actual (current) intake air volume ÷
maximum possible intake air volume × 100%
THROTTLE POS (ABSOLUTE THROTTLE POSITION,
%)
When throttle position sensor is at fully closed position,
throttle opening is indicated as 0 – 5% and 90 – 100%
full open position.
O2S SENSOR B1 S1 (HEA TED OXYGEN SENSOR-1,
V)
It indicates output voltage of HO2S-1 installed on
exhaust manifold (pre-catalyst).
)
TP SENSOR 2 VOLT Ignition switch ON after
warmed up engine Accelerator pedal released
1.4 – 1.8 V
Accelerator pedal depressed
fully 3.58 – 4.76 V
) APP SENSOR 1
VOLT Ignition switch ON after
warmed up engineAccelerator pedal released
0.5 – 0.9 V
Accelerator pedal depressed
fully 3.277 – 3.915 V
) APP SENSOR 2
VOLT Ignition switch ON after
warmed up engineAccelerator pedal released
1.3 – 1.7 V
Accelerator pedal depressed
fully 4.077 – 4.715 V
) ACCEL POSITION Ignition switch ON after
warmed up engine Accelerator pedal released
0 – 5%
Accelerator pedal depressed
fully 90 – 100%
) THROTTLE TARGET
POSI Ignition switch ON after
warmed up engineAccelerator pedal released
0 – 5%
Accelerator pedal depressed
fully 90 – 100%
) BATTERY
CURRENT At specified idle speed with no load after warming up
5.0 – 60.0 A
) GENERATOR CONT
DUTY (GENERATOR
CONTROL DUTY) At specified idle speed with no load after warming up
20.0 – 100.0%
) GENERATOR FIELD
DUTY (GENERATOR
FIELD COIL DUTY) At spe
cified idle speed with no load after warming up
20.0 – 100.0%
Scan tool data
Vehicle condition Normal condition /
reference values

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