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Home >> Suzuki >> 2012 >> Equator Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine General Information & Diagnosis - Qr25DE (2 Of 5) >> DTC P0137: Ho2S2 >> On Board Diagnosis Logic
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On Board Diagnosis Logic

The heated oxygen sensor 2 has a much longer switching time between rich and lean than the A/F sensor 1. The oxygen storage capacity before the three way catalyst (manifold) causes the longer switching time. To judge the malfunctions of heated oxygen sensor 2, ECM monitors whether the maximum voltage of the sensor is sufficiently high during various driving conditions such as fuel cut.

Fig 1: Driving Pattern Of Heated Oxygen Sensor
G06444092Courtesy of SUZUKI OF AMERICA CORP.
DTC DETECTING CONDITION CHART

DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0137
0137
Heated oxygen sensor 2 circuit low voltage The maximum voltage from the sensor does not reach the specified voltage.
  • Harness or connectors (The sensor circuit is open or shorted)
  • Heated oxygen sensor 2
  • Fuel pressure
  • Fuel injector
  • Intake air leaks