P0135 Mercury 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 Mercury 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 Mercury 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.
The ECM monitors the voltage signal received through the heater element circuit and determines the state of the circuit by comparing the voltage detected with the factory specifications.
What are the Possible Causes of the DTC P0135 Mercury?
- 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 Mercury?
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
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0135 Mercury 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 Mercury Code
What does the OBDII code P0135 mean for a Mercury vehicle?
Code P0135 indicates an issue with the oxygen (O2) sensor heater circuit for Bank 1 Sensor 1, which prevents the sensor from reaching optimal operating temperature.
What are the symptoms of code P0135 in a Mercury?
Common symptoms include poor fuel efficiency, rough idling, increased emissions, and possibly an illuminated check engine light.
What causes the P0135 code in Mercury vehicles?
Causes include a faulty O2 sensor, damaged wiring or connectors, blown fuses, or issues with the vehicle’s powertrain control module (PCM).
How is the P0135 code diagnosed in a Mercury?
A mechanic uses an OBDII scanner to confirm the code, checks the wiring and connectors for damage, tests the O2 sensor heater circuit, and verifies electrical continuity.
Can you still drive a Mercury with the P0135 code?
While the vehicle may still be drivable, prolonged operation can lead to reduced fuel efficiency and increased emissions, so repairs should be done promptly.
How do you fix the P0135 code on a Mercury?
Repairs may involve replacing the Bank 1 Sensor 1 O2 sensor, repairing damaged wiring, replacing blown fuses, or addressing PCM-related issues if applicable.
How much does it cost to fix the P0135 code in a Mercury?
Repair costs typically range from $150 to $400, depending on whether only the sensor needs replacement or additional repairs are required.
Can the P0135 code trigger other problems in a Mercury?
Yes, unresolved issues with the O2 sensor heater circuit can lead to poor engine performance, reduced fuel economy, and potential damage to the catalytic converter over time.
What tools are needed to address the P0135 code in a Mercury?
Essential tools include an OBDII scanner, multimeter for testing circuits, and appropriate wrenches or sockets for sensor replacement.
How can you prevent the P0135 code from appearing in a Mercury?
Regular maintenance, including periodic inspection of O2 sensors and wiring, can help prevent heater circuit malfunctions.
Discuss the causes and fixes for P0135 Mercury OBDII Code
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