DTC P0136: Heated Oxygen Sensor No. 2 Circuit Malfunction: Condition

DTC is set when HO2S No. 2 maximum output voltage is lower than predetermined or minimum output voltage is higher than predetermined. DTC is also set when HO2S No. 2 output voltage is 4.5 volts or more with engine at normal operating temperature. This circuit is monitored once per drive cycle. MIL is illuminated when Powertrain Control Module (PCM) detects malfunction during 2 consecutive drive cycles. Possible causes are:

• Exhaust system leak.
• Open or short to ground in circuit between HO2S No. 2 and PCM.
• HO2S No. 2 malfunction.
• Fuel system malfunction.