LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2008 >> Escape Base, 2.3 Z, AWD, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Powertrain DTC Charts And Descriptions (Except Diesel & Hybrid) >> DTC Diagnosis >> P0134 - O2 Circuit No Activity Detected (Bank 1, Sensor 1)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

P0134 - O2 Circuit No Activity Detected (Bank 1, Sensor 1)

P0134 - O2 CIRCUIT NO ACTIVITY DETECTED (BANK 1, SENSOR 1)

Description:  The powertrain control module (PCM) monitors the heated oxygen sensor (HO2S) for a lack of movement concern. If the sensor signal value is not changing from the default value, the PCM commands an oscillating air/fuel ratio attempting to detect some movement in the signal value. The test fails when the PCM is unable to detect movement in the sensor signal while the air/fuel ratio is oscillating.
Possible Causes: 
  • Open UO2SPC circuit
  • Damaged universal HO2S
Diagnostic Aids:   
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All   - refer to PINPOINT TEST DZ . refer to PINPOINT TEST DZ .