DTC P0051: Left Front Ho2S Heater Circuit Low: Condition

PCM monitors control signal at terminal No. 94. If PCM turns off heater (does not ground circuit) and voltage remains low, DTC is set. Causes may include the following:

• Faulty HO2S.
• Open or short to ground.
• Poor connection.
• PCM malfunction.

Left front O2 sensor heater is controlled by a duty signal.