P0135 Mercedes-Benz Code - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1
Quick Answer
Oxygen Sensors (O2S) or Heated Oxygen Sensors (HO2S) need to reach a minimum operating temperature of 750 degrees F to produce an accurate voltage signal. Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0135 Mercedes-Benz indicates O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1.
- Common causes
- Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0135 Mercedes-Benz Description
In order to achieve the require temperature, a heater element is included inside the heated oxygen sensor. The ECM controls the heated oxygen sensor heater element based on signals from the engine coolant temperature and engine load. The ECM controls the heater element circuit by allowing current flow to ground.
This fault code is stored in the engine control module when the current flow through the oxygen sensor heater circuit is not as expected. The ECM uses a comparator to measure the voltage drop across a known resistor, using this value the system can calculate the current flow within the circuit. The supply voltage to the component must be investigated. The resistance of the heater element should also be tested. A resistance of approximately 8 Ohms to 15 Ohms is satisfactory. Due to the location of this component the electrical connector can become contaminated with splash from the road. Separate the electrical connector and inspect the pins for corrosion.
What are the Possible Causes of the DTC P0135 Mercedes-Benz?
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit open shorted to ground
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0135 Mercedes-Benz?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
Mercedes Benz Code = 0436 (Right O2 sensor, before TWC): Heating capacity is too low. (P0135)
The code means that there is a problem with the heater element circuit of the heated oxygen sensor. The control module monitors how long it takes the sensor to warm up and start sending an adequate signal. The code is triggered when the sensor is taking too long to warm up. Water getting inside the heated oxygen sensor connector can be caused the heated oxygen sensor fuse to blow. Before replacing the sensor, check for the condition of the heated oxygen sensor fuse and connectors. If the sensor and connector are OK, replacing the O2 Sensor 1 usually takes care of the problem
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0135 Mercedes-Benz code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0135 Mercedes-Benz Code
1. What are the common symptoms of OBDII code P0135 in a Mercedes-Benz?
- Common symptoms include poor fuel economy, rough idling, issues with acceleration, and the illumination of the Check Engine Light.
2. What does the OBDII code P0135 indicating a O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1 mean for a Mercedes-Benz?
- This code indicates that there is a malfunction in the heating element circuit of the oxygen sensor located in Bank 1 Sensor 1 of the vehicle.
3. What are the possible causes of O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1 in a Mercedes-Benz?
- Common causes include a faulty oxygen sensor, damaged wiring or connectors, blown fuse, or issues with the engine control module.
4. How can I diagnose the O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1 in my Mercedes-Benz?
- Diagnosis involves using an OBDII scanner to retrieve the code, inspecting the wiring and connectors for damage, testing the oxygen sensor heater circuit, and checking the fuse related to the sensor.
5. Can I continue driving my Mercedes-Benz with the OBDII code P0135 present?
- It is generally not recommended to continue driving with this code present, as it can lead to decreased fuel efficiency and potential damage to other components over time.
6. How can I repair the O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 1 in my Mercedes-Benz?
- Repair typically involves replacing the oxygen sensor in Bank 1 Sensor 1, repairing or replacing any damaged wiring or connectors, and ensuring the fuse related to the sensor is in good condition.
7. What tools are needed to repair the O2 Sensor Heater Circuit Malfunction in a Mercedes-Benz?
- Tools needed may include an OBDII scanner, multimeter for testing circuits, wrench or socket set for removing components, and possibly a soldering iron for repairing wiring.
8. Can a DIY enthusiast repair the O2 Sensor Heater Circuit Malfunction in a Mercedes-Benz?
- Depending on the individual's skill level and access to tools, a DIY enthusiast may be able to successfully repair this issue. However, it is recommended to have some experience with automotive repairs.
9. How long does it take to repair the O2 Sensor Heater Circuit Malfunction in a Mercedes-Benz?
- The repair time can vary depending on the extent of the issue and the individual's experience. On average, it may take a couple of hours to half a day to diagnose and repair the problem.
10. Is it necessary to reset the OBDII code P0135 after repairing the O2 Sensor Heater Circuit Malfunction in a Mercedes-Benz?
- Yes, it is important to clear the code using an OBDII scanner after repairing the issue to reset the Check Engine Light and ensure the repair was successful.
Discuss the causes and fixes for P0135 Mercedes-Benz OBDII Code
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Both codes are for the same sensor Oxygen Sensor Bank 1 Sensor 1. The sensor is between $100-$150 plus one (1) of labor. The labor rate depends on the shop.
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