Page 107 of 557

6-56 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC CONFIRMATION PROCEDURE – Refer to DTC P0130 section.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Is there DTC(s) other than HO2S-1 (DTC P0133)?Go to applicable DTC
Diag. Flow Table.Replace HO2S-1.
DTC P0134 HEATED OXYGEN SENSOR (HO2S) CIRCUIT NO ACTIVITY
DETECTED (SENSOR-1)
WIRING DIAGRAM / CIRCUIT DESCRIPTION – Refer to DTC P0130 section.
DTC DETECTING CONDITION
POSSIBLE CAUSE
Engine warmed up.
While running under other than high load and high
engine speed conditions or at specified idle speed
(engine is in closed loop condition), HO2S-1 output
voltage is high or low continuously.
2 driving cycle detection logic, Continuous
monitoring.“G” or “R” circuit open or short
Heated oxygen sensor malfunction
Fuel system malfunction
Exhaust gas leakage
DTC CONFIRMATION PROCEDURE – Refer to DTC P0130 section.
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Is there DTC(s) other than Fuel system
(DTC P0171 / P0172) and HO2S-1 (DTC P0134)?Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3Check HO2S-1 and Its Circuit.
1) Connect scan tool to DLC with ignition switch
OFF.
2) Warm up engine to normal operating
temperature and keep it at 2000 r / min. for
60 sec.
3) Repeat racing engine (Repeat depressing
accelerator pedal 5 to 6 times continuously and
take foot off from pedal to enrich and enlean
A / F mixture).
Does HO2S-1 output voltage deflect between
0.3 V and over 0.6 V repeatedly?Go to DTC P0171 and
P0172 Diag. Flow Table
(Fuel System Check).Check “R” and “G” wires
for open and short, and
connections for poor
connection. If wires and
connections are OK,
replace HO2S-1.
Page 108 of 557

To generatorTo other sensor
Heater Ignition
switch Main
fuse
“IG COIL METER”
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-57
DTC P0135 HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT
MALFUNCTION (SENSOR-1)
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC will set when A or B condition is met.
A:
Low voltage at terminal C01-8 when engine is
running at high load.
B:
High voltage at terminal C01-8 when engine is
running under condition other than above.
2 driving cycle detection logic, Continuous
monitoring.HO2S-1 heater circuit open or shorted to ground
ECM (PCM) malfunction
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 with 2 persons, a driver and a tester.
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON, start engine and keep it at idle for 1 min.
3) Start vehicle and depress accelerator pedal fully for 5 sec. or longer.
4) Stop vehicle.
5) Check DTC in “DTC” mode and pending DTC in “ON BOARD TEST” or “PENDING DTC” mode.
Page 109 of 557

6-58 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Fig. 1 for Step 2 Fig. 2 for Step 3
C01-8
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check Heater for Operation.
1) Check voltage at terminal C01-8. See Fig. 1.
2) Warm up engine to normal operating temperature.
3) Stop engine.
4) Turn ignition switch ON and Check voltage atIntermittent trouble
Check for intermittent
referring to
“Intermittent and
Poor Connection”Go to Step 3.
terminal C01-8. See Fig. 1. Voltage should be
over 10 V.
5) Start engine, run it at idle and check voltage at the
same terminal. Voltage should be below 1.9 V.
Are check results are specified?in Section 0A.
3Check Heater of Sensor-1.
1) Disconnect HO2S-1 coupler with ignition switch
OFF.
2) Check for proper connection to HO2S-1 at “B/W”
and “P/B” wire terminals.
3) If OK, then check heater resistance. See Fig. 2.
Is it 11.7 – 14.3 Ω at 20C, 68F?“P/B” wire open or
shorted to ground or
poor connection at
C01-8. If wire and
connection are OK,
substitute a
known-good ECM
(PCM) and recheck.Replace HO2S-1.
Page 111 of 557

6-60 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
Usual driving: Driving at 30 – 40 mph, 50 – 60 km/h including short stop according to traffic signal. (under driving condition other than high-load,
high-engine speed, rapid accelerating and decelerating)1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11)and 50 mph
(80 km / h)
Above 20 mph
(32 km / h) Usual driving
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 with 2 persons, a driver and a tester, on a level road.
1) Turn ignition switch OFF.
Clear DTC with ignition switch ON, check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
–No exhaust gas leakage and loose connection
2) Warm up engine to normal operating temperature.
3) Drive vehicle under usual driving condition for 5 min. and check HO2S-2 output voltage and “short term fuel
trim” with “Data List” mode on scan tool, and write it down.
4) Stop vehicle (don’t turn ignition switch OFF).
5) Increase vehicle speed to higher than 20 mph, 32 km / h and then stop vehicle.
6) Repeat above steps 5) 4 times.
7) Increase vehicle speed to about 50 mph (80 km / h) in 3rd gear or 2 range.
8) Release accelerator pedal and with engine brake applied, keep vehicle coasting (fuel cut condition) for 10sec.
or more.
9) Stop vehicle (don’t turn ignition switch OFF) and run engine at idle for 2 min.
After this step 9), if “Oxygen Sensor Monitoring TEST COMPLETED” is displayed in “READINESS TESTS”
mode and DTC is not displayed in “DTC” mode, confirmation test is completed.
If “TEST NOT COMPLTD” is still being displayed, proceed to next step 10).
10) Drive vehicle under usual driving condition for 10 min. (or vehicle is at a stop and run engine at idle for 10 min.
or longer)
11) Stop vehicle (don’t turn ignition switch OFF). Confirm test results according to “Test Result Confirmation Flow
Table” in “DTC CONFIRMATION PROCEDURE” of DTC P0420.
Page 112 of 557
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-61
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check exhaust system for leakage, loose
connection and damage.
Is it good condition?Go to Step 3.Repair or replace.
3Check HO2S-2 and Its Circuit.
Was HO2S-2 output voltage indicated on scan
tool in step 3) of DTC confirmation test less
than 1.275 V?Go to Step 4.“Lg / B” or “R” circuit
open or HO2S-2
malfunction.
4Check Short Term Fuel Trim.
Did short term fuel trim very within –20 – + 20%
range in step 3) of DTC confirmation test?Check “R” and “Lg / B”
wire for open and short,
and connection for poor
connection. If wire and
connection are OK,
replace HO2S-2.Check fuel system. Go
to DTC P0171 / P0172
Diag. Flow Table.
Page 113 of 557
6-62 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
To other sensor
Heater Ignition
switch Main
fuse
“IG COIL METER”
To ignition coilTo other sensor
DTC P0141 HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT
MALFUNCTION (SENSOR-2)
CIRCUIT DESCRIPTION
DTC DETECTING CONDITIONPOSSIBLE CAUSE
DTC will set when A or B condition it met.
A. Low voltage at terminal C02-19 for specified time after engine
start or while engine running at high load.
B. High voltage at terminal C02-19 while engine running under
other than above condition.
2 driving cycle detection logic, continuous monitoring.HO2S-2 heater circuit open or shorted
to ground
ECM (PCM) malfunction
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF once and then ON.
2) Clear DTC, start engine and warm up engine to normal operating temperature.
3) Keep it at 2000 r / min for 2 min.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
Page 114 of 557

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-63
Fig. 1 for Step 2
INSPECTION
STEPACTIONYESNO
1Was “ENGINE DIAG. FLOW TABLE” performed?Go to Step 2.Go to “ENGINE DIAG.
FLOW TABLE”.
2Check HO2S-2 Heater and Its Circuit.
1) Warm up engine to normal operating temperature.
2) Stop engine.
3) Turn ignition switch ON and check voltage at
terminal C02-19 See Fig. 1. Voltage should be
over 10 V.
4) Start engine, run it at idle and check voltage at the
same terminal after 1 min. from engine start.
Voltage should be below 1.9 V.
Are check result as specified?Intermittent trouble.
Check for intermittent
referring to
“Intermittent and
Poor Connection”
in Section 0A.Go to Step 3.
3Check Heater or Sensor-2.
1) Disconnect HO2S-2 coupler with ignition switch
OFF.
2) Check for proper connection to HO2S-2 at “B/W”
and “Lg / B” wire terminals.
3) If OK, then check heater resistance.
Is it 11.7 – 14.3 Ω at 20C, 68F?“Lg / B” wire open or
shorted to ground or
poor connection at
C02-19. If wire and
connection are OK,
substitute a known-
good ECM (PCM)
and recheck.Replace HO2S-2.
Page 116 of 557

ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-65
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 with 2 persons, a driver and a tester on a level road.
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Check vehicle and environmental condition for:
–Altitude (barometric pressure): 2400 m, 8000 ft or less (560 mmHg, 75 kPa or more)
–Ambient temp.: –10C, 14F or higher
–Intake air temp.: 70C, 158F or lower
4) Start engine and drive vehicle under usual driving condition (described in DTC confirmation procedure of DTC
P0136) for 5 min. or longer and until engine is warmed up to normal operating temperature.
5) Keep vehicle speed at 30 – 40 mph, 50 – 60 km / h in 5th gear or “D” range for 5 min. or more.
6) Stop vehicle (do not turn ignition switch OFF).
7) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.