DTC P0134: O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)

OUTLINE OF DIAGNOSIS
Detect the open circuit of sensor.

Judge NG when the element impedance is large.
COMPONENT DESCRIPTION

Fig 1: O2 Sensor Circuit No Activity Detected Graph
Courtesy of SUBARU OF AMERICA, INC.

ENABLE CONDITION

ENABLE CONDITION CHART

Secondary Parameters	Enable Conditions
None

DIAGNOSTIC METHOD

Judge NG when the continuous time of completing the malfunction criteria below becomes more than 5 seconds.

Judgment Value

JUDGMENT VALUE CHART

Malfunction Criteria	Threshold Value
Voltage	"GREATER THAN EQUAL TO" 10.9 V
Time after engine starting	v 50 seconds
Cumulative amount of front lambda sensor heater control duty every 128 milli seconds	"GREATER THAN EQUAL TO" 28000%
Front O₂ (A/F) sensor impedance	"GREATER THAN EQUAL TO" 500 Ω:

Time Needed for Diagnosis: 5 seconds

Malfunction Indicator Light Illumination: Illuminates as soon as the malfunction occurs.

DTC CLEAR CONDITION
- When the OK idling cycle was completed 40 times in a row
- When "Clear Memory" was performed
MALFUNCTION INDICATOR LIGHT CLEAR CONDITION
- When the OK driving cycle was completed 3 times in a row
- When "Clear Memory" was performed
FAIL SAFE
- Front oxygen (A/F) sensor activation judgment: Front oxygen (A/F) sensor full activation is not complete, or front oxygen (A/F) sensor half activation is not complete.
- A/F main learning: Not allowed to calculate the A/F main learning compensation factor.
- Compensation when starting the engine at high temperature: Make the MIN value to be 0 from 0.3 normally.
- Purge control: Not allowed to purge.
ECM OPERATING AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)