Toyota Engine Light Questions And Answers
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Answer:Thanks for contacting us with your Toyota engine light question. Please refer to our article on Oxygen Sensor Diagnosis for some assistance with these codes. Both codes are for the the Air/Fuel sensor on bank 1, which is the bank towards the rear of the vehicle that includes cylinders 1, 3 and 5. The sensor is located in the exhaust pipe in front of the catalytic converter. The A/F sensor monitors the amount of oxygen in the gas and transmits this information to the computer so that it can adjust the fuel flow to maintain a correct air/fuel ratio (14.7:1). This sensor has a heater inside to bring it to temp. quickly, allowing for it to begin functioning sooner. Code P1135 is set when this heater output is more than 8 amps or less than .25 amps. Possible causes for this Toyota engine light code include the following. A/F sensor circuit is open or shorted. This could be a wiring concern or internal circuit concern which means the problem may exist in the A/F sensor itself or in the Electronic Control Module (ECM). Perform circuit tests as outlined in our Automotive Circuit Testing article to pinpoint the cause of this concern. You can check resistance across the sensor terminals with the sensor unplugged to determine if the heater is faulty. Measure across the pins with the Black/White and Black/Red wires on the sensor side, not the harness side. At 68F ambient temperature resistance should be .8 to 1.4 ohms. Toyota engine light code P1130 is set when the sensor voltage output remains the same with the engine running after it is at operating temperature. Possible causes for this code are the same as P1135, but also include a faulty fuel injector, air intake system leak or fuel pressure concern. From my experience, both of these codes are likely related. ECM failure is very uncommon, so I would suspect a wiring concern or internal A/F sensor problem. Check to be sure the connector is secure and plugged in correctly and then proceed with wiring tests. With an OBD II scan tool you can monitor the output voltage of the Air/Fuel sensor and it should switch from low to high values between 0 and 1 volt. I hope this information is helpful! Let me know if you need help with any future Toyota engine light concerns! Thanks, and enjoy the day!