DTC P0136: Heated Oxygen Sensor Circuit High Voltage (sensor 2)

CIRCUIT OPERATION
• A voltage corresponding to the oxygen concentration in the exhaust gas is sent to the ECM (terminal No. 75) <M/T> or PCM (terminal No. 73) <A/T> from the output terminal (terminal No. 1) of the heated oxygen sensor (rear).
• Terminal No. 2 of the heated oxygen sensor (rear) is grounded with ECM (terminal No. 92) <M/T> or PCM (terminal No. 57) <A/T>.
TECHNICAL DESCRIPTION
• The output signal of the heated oxygen sensor (front) is compensated by the output signal of the heated oxygen sensor (rear).
• The ECM <M/T> or PCM <A/T> checks for an open circuit in the heated oxygen sensor (rear) output line.
DESCRIPTIONS OF MONITOR METHODS
• While the heated oxygen sensor (rear) output is low, 5 volts are applied to the input circuit of the heated oxygen sensor (rear). An open circuit is detected while monitoring the sensor output with 5 volts applied.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
• Heated oxygen sensor heater (front) monitor
• Heated oxygen sensor heater (rear) monitor
• Air/fuel ratio feedback monitor

Sensor (The sensor below is determined to be normal)
• Volume airflow sensor
• Engine coolant temperature sensor
• Intake air temperature sensor
• Barometric pressure sensor
DTC SET CONDITIONS Logic Flow Chart


Check Conditions
3 minutes or more have passed since the starting sequence was completed.
Heated oxygen sensor (rear) signal voltage has continued to be 0.15 volt or lower.
Engine coolant temperature is higher than 76°C (169°F).
Engine speed is higher than 1,200 r/min.
Volumetric efficiency is higher than 25 percent.
Monitoring time: 7 seconds.

Judgment Criterion
• Input voltage supplied to the ECM <M/T> or PCM <A/T> interface circuit is higher than 4.5 volts when 5 volts is applied to the heated oxygen sensor (rear) output line via a resistor.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 11 .
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:
• Heated oxygen sensor (rear) failed.
• Open circuit in heated oxygen sensor (rear) output line.
• Open circuit in heated oxygen sensor (rear) ground line.
• ECM failed. <M/T>
• PCM failed. <A/T>