ho2s SUZUKI SWIFT 2007 2.G Service User Guide

Downloaded from www.Manualslib.com manuals search engine 1A-28 Engine General Information and Diagnosis:
) *P0031 HO2S heater control circuit low
(Sensor-1) Heater voltage is less than specification while heater ON. 2 driving
cycles
) *P0032 HO2S heater control circuit
high (Sensor-1) Heater voltage is more than
specification while heater
ON. 2 driving
cycles
) *P0037 HO2S heater control circuit low
(Sensor-2) Heater voltage is less than specification while heater ON. 2 driving
cycles
) *P0038 HO2S heater control circuit
high (Sensor-2) Heater voltage is more than
specification while heater
ON. 2 driving
cycles
)
U *P0101 Mass or volume air flow circuit
range/performance MAF sensor volume is more
than specification or less
than specification. 2 driving
cycles
) *P0102 Mass or volume air flow circuit
low input Output voltage of MAF sensor is less than specification. 1 driving
cycle
) *P0103 Mass or volume air flow circuit
high input Output voltage of MAF sensor is more than specification. 1 driving
cycle
)
U *P0106 Manifold absolute pressure/
barometric pressure circuit
range/performance Difference between Max. manifold absolute pressure
value and Min. manifold pressure value is less than
specification or difference between barometric pressure
value and manifold pressure value is less than
specification
2 driving
cycles
) *P0107 Manifold absolute pressure/
barometric pressure circuit low
input Output voltage of MAP sensor
is less than specification.1 driving
cycle
) *P0108 Manifold absolute pressure/
barometric pressure circuit high
input Output voltage of MAP sensor is more than specification.
1 driving
cycle
)
U *P0111 Intake air temperature sensor 1
circuit range/performance Variation of intake air temperature from engine start is
less than specification. 2 driving
cycles
) *P0112 Intake air temperature sensor 1
circuit low Circuit voltage of IAT sensor is less than specification. 1 driving
cycle
) *P0113 Intake air temperature sensor 1
circuit hig

h Circuit voltage of IAT sensor
is more than specification. 1 driving
cycle
)
U *P0116 Engine coolant temperature
circuit range/performance Engine coolant temperature is less than specified
temperature for specified time from engine start. 2 driving
cycles
) *P0117 Engine coolant temperature
circuit low Circuit voltage of ECT sensor
is less than specification. 1 driving
cycle
) *P0118 Engine coolant temperature
circuit high Circuit voltage of ECT sensor
is more than specification. 1 driving
cycle
) *P0122 Throttle/pedal position sensor/
switch “A” circuit low Output voltage of TP sensor (main) is lower than
specification. 1 driving
cycle
) *P0123 Throttle/pedal position sensor/
switch “A” circuit high Output voltage of TP sensor (main) is higher than
specification. 1 driving
cycle
)
U *P0131 O2 sensor (HO2S) circuit low
voltage (Sensor-1)
Max. output voltage of HO2S-1
is less than specification.2 driving
cycles
)
U *P0132 O2 sensor (HO2S) circuit high
voltage (Sensor-1)
Min. output voltage of HO2S-1
is more than specification. 2 driving
cycles
)
U *P0133 O2 sensor (HO2S) circuit slow
response (Sensor-1) Response time of HO2S-1 output voltage between rich
and lean is longer than specification. 2 driving
cycles
) *P0134 O2 sensor (HO2S) circuit no
activity detected (Sensor-1) Output voltage of HO2S-1 is
more than specification or
less than specification. (or HO2S-1 circuit open or short) 2 driving
cycles
)
U *P0137 O2 sensor (HO2S) circuit low
voltage (Sensor-2) Output voltage of HO2S-2 is
less than specification while
engine is idling after driving with high engine load and
Max. output voltage of HO2S-2 minus Min. output voltage
of HO2S-2 is less than specification. 2 driving
cycles
)
U *P013

8 O2 sensor (HO2S) circuit high
voltage (Sensor-2) Output voltage of HO2S-2 is
more than specification while
engine is idling after driving with high engine load and
Max. output voltage of HO2S-2 minus Min. output voltage
of HO2S-2 is less than specification. 2 driving
cycles
DTC No. Detecting item
Detecting condition
(DTC will set when detecting:) MIL

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-29
) *P0140 O2 sensor (HO2S) circuit no
activity detected (Sensor-2) Output voltage of HO2S-2 is more than specification after
warming up engine. 2 driving
cycles
)
{ *P0171 System too lean Total fuel trim is larger than
specification for specified time
or longer. (Fuel trim towa rd rich side is large.) 2 driving
cycles
)
{ *P0172 System too rich Total fuel trim is smaller th
an specification for specified
time or longer. (Fue l trim toward lean side is large.) 2 driving
cycles
) *P0222 Throttle/pedal position sensor
(sub)/switch “B” circuit low Output voltage of TP sensor (sub) is lower than
specification 1 driving
cycle
) *P0223 Throttle/pedal position sensor
(sub)/switch “B” circuit high Output voltage of TP sensor (sub) is higher than
specification 1 driving
cycle
)
U *P0300 Random/multiple cylinder
misfire detected Misfire of such level as to cause damage to three way
catalyst. *2 driving
cycles
)
U *P0301 /
U *P0302 /
U *P0303 /
U *P0304 Cylinder 1 misfire detected
Cylinder 2 misfire detected
Cylinder 3 misfire detected
Cylinder 4 misfire detected
Misfire of such level as to deteriorate emission but not to
cause damage to three way catalyst.
*2 driving
cycles
) *P0327 Knock sensor 1 circuit low Output voltage of knock sensor is less than specification.1 driving
cycle
) *P0328 Knock sensor 1 circuit high Output volta ge of knock sensor is more than specification.1 driving
cycle
) *P0335 Crankshaft position sensor “A”
circuit No signal of CKP sensor for sp
ecified time even if starting
motor signal is input. 1 driving
cycle
) *P0340 Camshaft position sensor “A”
circuit CMP sensor pulse is out of specification. 1 driving
cycle
) † P0350 Ignition c
oil primary /
secondary circuit Ignition signal is not inputted to monitor circuit 5 times or
more continuously. 1 driving
cycle
)
{ *P0401 Exhaust gas recirculation flow
insufficient detected Difference in intake manifold absolute pressure between
opened EGR valve and closed EGR valve is less than
specification. 2 driving
cycles
)
{ *P0402 Exhaust gas recirculation flow
excessive detected Difference in intake manifold absolute pressure between
opened EGR valve and closed EGR valve is more than
specification. 2 driving
cycles
) *P0403 Exhaust gas recirculation
control circuit Output voltage is different from output command with
more than one pole out of 4 poles. 1 driving
cycle
)
U *P0420 Catalyst system efficiency
below threshold
Output waveforms of HO2S-1 and HO2S-2 are similar. 2 driving
cycles
) *P0443 Evaporative emission system
purge control valve circuit Monitor signal of EVAP canister purge valve is different
from command signal. (circuit open or shorted to ground) 2 driving
cycles
) *P0480 Fan 1 (Radiator cooling fan)
control circuit Monitor signal of radiator cooling fan relay is different from
command signal. 1 driving
cycle
) *P0500 Vehicle speed sensor “A” No VSS signal during fuel cut fo
r specified time or longer,
or VSS signal is not input even if vehicle is driving with
more than specified engine speed and D-range (for A/T
model). 2 driving
cycles
) P0532 A/C refrigerant pressure sensor
“A” circuit low Output voltage of A/C refrigerant pressure sensor is less
than specification.
—
) P0533 A/C refrigerant pressure sensor
“A” circuit high Output voltage of A/C refrigerant pressure sensor is more
than specification.
—
) *P0601 Internal control module
memory check sum error Data write error or check sum error. 1 driving
cycle
) P0602 Control module programming
error Data programming error.
—
) *P0607 Control module performance Data programming error. 1 driving
cycle
)
U *P061

6Starter relay circuit low Starter signal is low voltage even though engine is started
with vehicle at stop. 2 driving
cycles
DTC No. Detecting item
Detecting condition
(DTC will set when detecting:) MIL

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-31
Fail-Safe TableS7RS0B1104006
When any of the following DTCs is detected, ECM enters fail-safe mode as long as malfunction continues to exist but
that mode is canceled when ECM de tects normal condition after that.
)
*P2123 Throttle/pedal position sensor/
switch “D” (main) circuit high
input Output voltage of APP sensor (main) is higher than
specification.
1 driving
cycle
) *P2127 Throttle/pedal position sensor/
switch “E” (sub) circuit low
input Output voltage of APP sens
or (sub) is lower than
specification. 1 driving
cycle
) *P2128 Throttle/pedal position sensor/
switch “E” (sub) circuit high
input Output voltage of APP sensor (sub) is higher than
specification.
1 driving
cycle
) *P2135 Throttle/pedal position sensor/
switch “A”/“B” (main / sub)
voltage correlation Difference between the opening angle based on TP
sensor (main) and the opening angle based on TP sensor
(sub) is more than specification.
1 driving
cycle
) *P2138 Throttle/pedal position sensor/
switch “D”/“E” (main / sub)
voltage correlation Difference between the opening angle based on APP
sensor (main) and the opening angle based on APP
sensor (sub) is more
than specification. 1 driving
cycle
)
U *P2227 Barometric pressure circuit
range/performance Difference of barometric pressure value and intake
manifold pressure value is
more than specification at
engine start. 2 driving
cycles
) *P2228 Barometric pressure circuit low Barometric pressure sens
or voltage is less than
specification. 1 driving
cycle
) *P2229 Barometric pressure circuit
high Barometric pressure sensor voltage is more than
specification. 1 driving
cycle
) P1614 Transponder response error
Refer to “Diagnostic Trouble Code (DTC) Table in Section
10C”. —

) P1615 ID code does not registered
(vehicle equipped with keyless
start system only)
) P1616 Different registration ID codes
(vehicle equipped with keyless
start system only)
) P1618 CAN communication error
(reception error for keyless
start control module) (vehicle
equipped with keyless start
system only)
) P1621 Immobilizer communication
line error
) P1622
EEPROM error
) P1623 Unregistered transponder
) P1625 Immobilizer antenna error
) P1636 Immobilizer information
registration failure
) P1638 Immobilizer information
mismatched
DTC No. Detecting item
Detecting condition
(DTC will set when detecting:) MIL
DTC No.
Detected item Fail-safe operation
) P0031 HO2S heater control circuit low (Sensor-1)
ECM stops air/fuel ratio control.
) P0032 HO2S heater control circuit high (Sensor-1)
) P0102 Mass or volume air flow circuit low input • ECM controls injector drive time (fuel injection
volume) according to throttle valve opening
(closed throttle position or not).
• ECM stops EGR control.
)
P0103 Mass or volume air flow circuit high input
) P0112 Intake air temperature sensor 1 circuit low ECM controls actuators assuming that intake air
temperature is 20 °C (68 ° F).
) P0113 Intake air temperature sensor 1 circuit high

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-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 1A-54 Engine General Information and Diagnosis:
DTC P0031 / P0032: HO2S Heater Control Circuit Low / High (Sensor-1)S7RS0B1104015
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle speed for 1 min. or more.
5) 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.

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
BLK/WHT
WHT
11
GRN
3 9
E23-29
WHT
YEL
BLK/WHT
BLKC37-46
C37-10
C37-57
6
7
10
BLK
BLUWHT
BLK/RED
4
5
8
12
1
I6RS0C110006-03
1. Main fuse box
4. Junction block assembly 7. Heater 10. To HO2S-2
2. Shield wire 5. “IG COIL” fuse8. To HO2S-2 heater 11. Individual circuit fuse box No.1
3. Ignition switch 6. HO2S-19. ECM 12. “IG ACC” fuse
DTC detecting condition Trouble area
HO2S-1 heater voltage is more than specified value or lower
than specified value for 5 seconds continuously.
(2 driving cycle detection logic) • HO2S-1 heater circuit
• HO2S-1 heater
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-55
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-1 heater power circuit check
1) Disconnect connector from HO 2S-1 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-1 at “BLK/WHT” and “BLK/RED” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal and engine ground
with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-1 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-1 connector and “E 23-29” terminal of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-1 heater drive circuit check
1) Measure resistance between “C37-46” terminal of ECM
connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “BLK/RED” wire is
shorted to ground
circuit.
5 HO2S-1 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “C37-46” terminal of ECM
connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “BLK/RED” wire is
shorted to power circuit.
6 HO2S-1 heater drive circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-46” terminal of ECM connector and vehicle body ground with connector
disconnected from ECM.
Is voltage over 10 V? Go to Step 7. “BLK/RED” wire is open
circuit.
7 HO2S-1 heater check
1) Disconnect HO2S-1 connector with ignition switch
turned OFF.
2) Check HO2S-1 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value range? Go to Step 8. Replace HO2S-1.
8 HO2S-1 heater power circuit check
1) Connect connector to HO2S-1 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-46” terminals of ECM connector.
It resistance below 12
Ω? Substitute a known-
good ECM and recheck.
“BLK/WHT”, “BLK/RED”
and / or “BLK” wire is
high resistance circuit.

Downloaded from www.Manualslib.com manuals search engine 1A-56 Engine General Information and Diagnosis:
DTC P0037 / P0038: HO2S Heater Control Circuit Low / High (Sensor-2)S7RS0B1104016
Wiring Diagram
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Run engine at idle speed for 1 min.
5) 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.

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
BLK/WHT
WHT
11
GRN
3 9
E23-29
BRN
YEL
BLK/WHT
BLKC37-47
C37-11
C37-57
6
2
7
10
BLK
BLUWHT
RED/BLU
1
4
5
8
12
5V
I6RS0C110007-01
1. Main fuse box 4. Junction block assembly 7. Heater 10. To HO2S-1
2. Shield wire 5. “IG COIL” fuse8. To HO2S-1 heater 11. Individual circuit fuse box No.1
3. Ignition switch 6. HO2S-29. ECM 12. “IG ACC” fuse
DTC detecting condition Trouble area
HO2S-2 heater voltage is more than specified value or less than
specified value for 5 seconds continuously
(2 driving cycle detection logic) • HO2S-2 heater
• HO2S-2 heater circuit
•ECM

Downloaded from www.Manualslib.com manuals search engine Engine General Information and Diagnosis: 1A-57
StepAction YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 HO2S-2 heater power circuit check
1) Disconnect connector from HO 2S-2 with ignition switch
turned OFF.
2) Check for proper connection to HO2S-2 at “BLK/WHT” and “RED/BLU” wire terminals.
3) If wire and connection are OK, measure voltage between “BLK/WHT” wire terminal of HO2S-2 connector
and engine ground with ignition switch turned ON.
Is voltage over 10 V? Go to Step 3.
“BLK/WHT” wire is open
circuit or shorted to
ground circuit.
3 HO2S-2 heater power circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure resistance between “BLK/WHT” wire terminal of HO2S-2 connector and “E23-29” terminal wire of ECM
connector.
Is resistance below 5
Ω? Go to Step 4. “BLK/WHT” wire is high
resistance circuit.
4 HO2S-2 heater drive circuit check
1) Measure resistance between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is resistance infinity? Go to Step 5. “RED/BLU” wire is
shorted to ground
circuit.
5 HO2S-2 heater drive circuit check
1) Turn ON ignition switch.
2) Measure voltage between “RED/BLU” wire terminal of
HO2S-2 connector and vehicle body ground.
Is voltage 0 V? Go to Step 6. “RED/BLU” wire is
shorted to power circuit.
6 HO2S-2 heater drive circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Turn ON ignition switch.
3) Measure voltage between “C37-47” terminal of disconnected ECM connector and vehicle body ground.
Is voltage over 10 V? Go to Step 7.
“RED/BLU” wire is open
circuit.
7 HO2S-2 heater check
1) Disconnect HO2S-2 connector with ignition switch
turned OFF.
2) Check HO2S-2 heater resistance referring to “HO2S-1 and HO2S-2 Heater On-Vehicle Inspection in Section
1C”.
Is resistance within specified value? Go to Step 8.
Replace HO2S-2.
8 HO2S-2 heater power circuit check
1) Connect connector to HO2S-2 with ignition switch turned
OFF.
2) Measure resistance between “E23-29” and “C37-47” terminals of ECM connector.
Is resistance below 30
Ω? Substitute a known-
good ECM and recheck.
“RED/BLU” wire is high
resistance circuit.