PZEV Model
Advanced DiagnosticsDTC P0135: Rear Air/Fuel Ratio (A/F) Sensor (Bank 1,Sensor 1) Heater Circuit Malfunction (PZEV Model)
General Description
A heater for the sensor element is embedded in the rear air/fuel ratio (A/F) sensor (bank 1, sensor 1), and it is controlled by the powertrain control module (PCM). It is activated and heats the sensor to stabilize and speed up the detection of oxygen content when the exhaust gas temperature is cold. The PCM monitors the rear A/F sensor heater output (return check). A malfunction is detected if the return signals do not meet the command value (for heater activation) in the PCM for a set time or more and a DTC is stored.
Monitor Execution, Sequence, Duration, DTC Type, OBD Status
Enable Conditions
Malfunction Threshold
One of these condition must be met for at least 2 seconds.
- No return signal "HIGH" is detected when the PCM output duty is less than 20 %.
- Return signal does not change when the PCM output duty is more than 20 % and less than 80 %.
- No return signal "LOW" is detected when the PCM output duty is more than 80 %.
Driving Pattern
Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) until the radiator fan comes on, then let it idle.
Diagnosis Details
Conditions for illuminating the MIL
When a malfunction is detected during the first drive cycle, a Temporary DTC is stored in the PCM memory. If the malfunction recurs during the next (second) drive cycle, the MIL comes on and the DTC and the freeze frame data are stored.
Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive drive cycles in which the engine conditions are similar to the first time the malfunction was detected. The MIL, the DTC, the Temporary DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.