Powertrain, generic · Fuel and air metering

P0154 O2 Sensor Circuit No Activity Detected Bank 2 Sensor 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The oxygen sensor before the catalytic converter on bank 2 (sensor 1) is the main control sensor for the mixture. It is either a switching sensor (about 0.1 V lean to 0.9 V rich) or a wide-band sensor that works with a pump current evaluated by an interface chip. Bank 2 exists only on engines with two exhaust manifolds. P0154 is the bank 2 counterpart of P0134: the sensor delivers no moving signal and the control module only sees its own bias voltage. On GM's 3.0/3.6 V6 the code is set when the signal stays at 350–550 mV after heater warm-up, within about 15 s, in closed loop after 150 s of running; two trips. Ford's Bosch wide-band systems have used P2240 instead since 2011. A failed heater (P0155) can also lead to this code. A stored code usually switches mixture control to open loop and suspends adaptation and converter monitoring.

Likely causes

Open or high-resistance signal or ground wire, connector loose or corroded
Sensor faulty (cell high-resistance, worn out)
Sensor heater faulty – sensor does not get hot enough
Control module bias or measuring circuit faulty

Symptoms

  • Check engine light on
  • No mixture control (open loop), higher consumption
  • Higher emissions, possible emissions test failure

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–350
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

oxygen sensor bank2 sensor1oxygen sensor wiringengine control module

Related codes

P0134P0153P0155P0151P0152P2240

References: law.cornell.edu, saabwisonline.com, newtonnet.co.uk.