P0135 is an error indicating the failure of the oxygen sensor heating circuit (bank 1, sensor 1). This error code tells the driver that there are failures in the heating mechanism of the first lambda probe that is installed before the catalytic converter. P0135 error can be determined using a scan tool or self-diagnostics (using a paper clip and counting blinks of the check icon in the dash panel). Since there may be no other signs indicating a problem with the heating of the oxygen sensor.
The malfunction of the 1st lambda may not affect the operation of the engine. This can only be indicated by the CHECK ENGINE indicator. Fuel consumption usually does not increase, or increases just a little (unlike the error O2S2, code P0136), except that there will be a slight loss of dynamics and a little more acute exhaust sound, as well as the acridness smell. Everything depends on the car model and the features of the master controller.
Error p0135 is recorded in the ECM memory while the engine is running, when the temperature of the converter is much higher than the set one, and the resistance of the oxygen sensor is higher than the required one. This code is recorded in the ECU event archive and can be displayed even if the problem is eliminated. Therefore, to determine the problem in the system, you need to switch on not only self-diagnostics mode, but also test mode, and reset the existing records in the archive.
Causes of the P0135 error
There are not so many failures caused by the oxygen sensor heater and you can easily determine them using a multimeter:
- Contact fault in the sensor supply shoe (oxides).
- Wire breaking /short circuit in the heater.
- Failure of O2S.
- Other errors resulting in failure.
Thus, to eliminate the cause of errors of the exhaust heater, you need to check lambda probe alternately.
Error elimination in the heater circuit
First, make sure of the integrity of the sensor wiring, and then check the state of the contact plug (remove corrosion). Then it is recommended to check the resistance of the lambda heating. While the engine is warm, remove the plug from the sensor at the standard temperature of 20 °C and measure the resistance between two wires of the same color (they are powered by 12V).
In addition to resistance, you can also check the number of the voltmeter arrow deflections for 10 sec. and if the sensor readings are the same, the error code p0134 would be in the memory (sensor signal activity is absent).
When you have performed all of the above mentioned actions, cleaned the contacts or replaced the sensor, error P0135 should disappear after a few minutes of the engine operation. If you have a computer with a special program, you can check it and delete the recorded event in the archive. You can also reset the error by removing the terminal from the accumulator.