DTC P0140: Rear Ho2S Circuit, No Activity Detected: Condition

DTC is set when rear HO2S signal voltage does not exceed .55 volt for 54.2 seconds after engine coolant temperature has reached more than 176°F (80°C) and engine speed is more than 1500 RPM. Powertrain Control Module (PCM) checks rear HO2S operation during HO2S/TWC monitor repair verification drive mode. See DRIVE MODES  under SELF-DIAGNOSTIC SYSTEM. This is a continuous monitor. MIL is illuminated when PCM detects malfunction during 2 consecutive drive cycles. Possible causes are:

• Rear HO2S.
• Exhaust system leak.
• Open or short between rear HO2S and PCM.
• Low engine compression.
• Engine malfunction.