Toyota Sequoia (2005). Manual - part 87

–

DIAGNOSTICS

ENGINE

DI–151

345

MONITOR STRATEGY

P0136

Heated rear oxygen sensor (Bank 1) output volt-
age (Output voltage)

P0136

Heated rear oxygen sensor (Bank 1) impedance

(Low)

P0137

Heated rear oxygen sensor (Bank 1) output volt-
age (Low voltage)

P0137

Heated rear oxygen sensor (Bank 1) impedance

(High)

P0138

Heated rear oxygen sensor (Bank 1) output volt-
age (High voltage)

R l t d DTC

P0138

Heated rear oxygen sensor (Bank 1) output volt-
age (Extremely high)

Related DTCs

P0156

Heated rear oxygen sensor (Bank 2) output volt-
age (Output voltage)

P0156

Heated rear oxygen sensor (Bank 2) impedance

(Low)

P0157

Heated rear oxygen sensor (Bank 2) output volt-
age (Low voltage)

P0157

Heated rear oxygen sensor (Bank 2) impedance

(High)

P0158

Heated rear oxygen sensor (Bank 2) output volt-
age (High voltage)

P0158

Heated rear oxygen sensor (Bank 2) output volt-
age (Extremely high)

R

i d

/

t

Main sensors/components

Heated rear oxygen sensor

Required sensors/components

Related sensors/components

Mass air flow meter

Frequency of operation

Once per driving cycle: Active air–fuel ratio control detection
Continuous: Others

Duration

20 sec.: Heated oxygen sensor output (Output voltage, High voltage, Low voltage)

30 sec.: Heated oxygen sensor impedance (Low)
90 sec.: Heated oxygen sensor impedance (High)
10 sec.: Heated oxygen sensor impedance (Extremely high)

MIL operation

2 driving cycles Heated oxygen sensor output (Output voltage, High voltage, Low voltage)

Immediate: Heated oxygen sensor impedance (Low, High, Extremely high)

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

The monitor will run whenever these

DTCs are not present

See page 

DI–18

Heated oxygen sensor output voltage (Output voltage, High voltage and Low voltage):

Active air–fuel ratio control

Executing

Active air–fuel ratio control being when all
of following conditions met

–

Battery voltage

11 V

–

Engine coolant temperature

75

°

C (167

°

F)

–

Idle

OFF

Engine RPM

–

3,200 rpm

DI–152

–

DIAGNOSTICS

ENGINE

346

A/F sensor status

Activated

Fuel–cut

OFF

Engine load

10 to 70%

Shift position

4th

–

Heated oxygen sensor impedance (Low):

Battery voltage

11 V

–

Estimated sensor temperature

–

700

°

C (1,292

°

F)

ECM monitor

Completed

P0606

Not set

Heated oxygen sensor impedance (High):

Battery voltage

11 V

–

Estimated sensor temperature

450

°

C (842

°

F)

–

ECM monitor

Completed

P0606

Not set

Heated oxygen sensor output voltage (Extremely high):

Battery voltage

11 V

–

Time after engine start

2 sec.

–

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

Heated oxygen sensor output voltage (Output voltage):

Either of the following conditions is met:

Condition 1 or 2

1. All of the following conditions are met:

Condition (a), (b) and (c)

(a) Commanded air–fuel ratio

14.3 or less

(b) Rear HO2S voltage

0.21 to 0.59 V

(c) OSC (Oxygen Storage Capacity of catalyst)

3 g or more

2. All of the following conditions are met:

Condition (a), (b) and (c)

(a) Commanded air–fuel ratio

14.9 or more

(b) Rear HO2S voltage

0.21 to 0.59 V

(c) OSC (Oxygen Storage Capacity of catalyst)

3 g or more

Heated oxygen sensor output voltage (Low voltage):

All of the following conditions are met:

Condition 1, 2 and 3

1. Commanded air–fuel ratio

14.3 or less

2. Rear HO2S voltage

Less than 0.21 V

3. OSC (Oxygen Storage Capacity of catalyst)

3 g or more

Heated oxygen sensor output voltage (High voltage):

All of the following conditions are met:

Condition 1, 2 and 3

1. Commanded air–fuel ratio

14.9 or more

2. Rear HO2S voltage

More than 0.59 V

3. OSC (Oxygen Storage Capacity of catalyst)

3 g or more

Heated oxygen sensor impedance (Low):

Duration of following condition

30 sec. or more

Heated oxygen sensor impedance

Less than 5 

Ω

Heated oxygen sensor impedance (High):

Duration of following condition

90 sec. or more

–

DIAGNOSTICS

ENGINE

DI–153

347

Heated oxygen sensor impedance

348.1 M

Ω

 or more

Heated oxygen sensor output voltage (Extremely high):

Duration of following condition

10 sec. or more

Heated oxygen sensor voltage

More than 1.2 V

COMPONENT OPERATING RANGE

Parameter

Standard Value

Heated oxygen sensor voltage

Varies between 0.1 to 0.9 V

MONITOR RESULT

Refer to page 

DI–24

 for detailed information.

The test value and test limit information are described as shown in the following table. Check the monitor
result and test values after performing the monitor drive pattern (refer to ”Confirmation Monitor”).

MID (Monitor Identification Data) is assigned to each emissions–related component.

TID (Test Identification Data) is assigned to each test value.

HO2S bank 1 sensor 2

MID

TID

Scaling

Description of Test Value

Minimum Test Limit

Maximum Test Limit

$02

$07

Multiply by 0.001

(V)

Minimum sensor voltage

Minimum test limit

Maximum test limit

$02

$08

Multiply by 0.001

(V)

Maximum sensor voltage

Minimum test limit

Maximum test limit

$02

$8F

Multiply by 0.001

(g)

Maximum oxygen storage capacity

0

Maximum test limit

HO2S bank 2 sensor 2

MID

TID

Scaling

Description of Test Value

Minimum Test Limit

Maximum Test Limit

$06

$07

Multiply by 0.001

(V)

Minimum sensor voltage

Minimum test limit

Maximum test limit

$06

$08

Multiply by 0.001

(V)

Maximum sensor voltage

Minimum test limit

Maximum test limit

$06

$8F

Multiply by 0.001

(g)

Maximum oxygen storage capacity

0

Maximum test limit

WIRING DIAGRAM

Refer to DTC P2195 on page 

DI–383

.

A23661

Vehicle Speed

(64 km/h and 113 km/h)

Between 
40 mph and 70 mph

Idling

Ignition Switch OFF

10 minutes

Time

Warm up

(Note: Even if vehicle stops during driving pattern, test can be resumed)

NOTICE: 
This test will not be completed 
if the vehicle is driven under 
absolutely constant speed 
conditions such as with cruise 
control activated.

(h)

(g)

MISFIRE MON ..................... AVAIL

READINESS TESTS

CAT EVAL ......................... INCMPL
HTD CAT EVAL ...................... N/A
EVAP EVAL ....................... INCMPL
2nd AIR EVAL .......................... N/A
A/C EVAL ................................ N/A
O2S EVAL ........................ INCMPL
O2S HTR EVAL .................. INCMPL
EGR EVAL ...............................N/A

COMP MON ........................ AVAIL

FUEL SYS MON ................... AVAIL

A76855

A23660

DI–154

–

DIAGNOSTICS

ENGINE

348

CONFIRMATION DRIVING PATTER

HINT:

This confirmation driving pattern is used in steps 5, 8 and 11 of the following diagnostic troubleshooting
procedure when using either a hand–held tester.

Performing this confirmation pattern will activate the Heated Oxygen (HO2) sensor monitor. (The cata-
lyst monitor is performed simultaneously.) This is very useful for verifying the completion of a repair.

(a)

Connect a hand–held tester to the DLC3.

(b)

Turn the ignition switch to ON.

(c)

Turn the tester or scan tool ON.

(d)

Clear DTCs (where set) (see page 

DI–43

).

(e)

If using a hand–held tester, select the following menu
items: DIAGNOSIS / CARB OBD II / READINESS
TESTS.

(f)

Check that O2S EVAL is INCMPL (incomplete).

(g)

Start the engine and warm it up.

(h)

Drive the vehicle at between 40 mph and 70 mph (64 km/h
and 113 km/h) for at least 10 minutes.

(i)

Note the state of the Readiness Tests items. Those items
will change to COMPL (complete) as O2S EVAL monitor
operates.

(j)

On the tester, select the following menu items: DIAGNO-
SIS / ENHANCED OBD II / DTC INFO / PENDING
CODES and check if any DTCs (any pending DTCs) are
set.

HINT:
If O2S EVAL does not change to COMPL, and any pending
DTCs fail to set, extend the driving time.