P0037 Infiniti Code - HO2S12 Heater Control Circuit Low
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 2, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 fuse, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 harness is open or shorted. 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
- P0037 Infiniti indicates HO2S12 Heater Control Circuit Low.
- Common causes
- Common causes include Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 fuse, Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 harness is open or shorted.
- 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 P0037 Infiniti 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 P0037 Infiniti?
- Faulty Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 fuse
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 harness is open or shorted
- Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2 circuit poor electrical connection
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0037 Infiniti?
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 P0037 Infiniti code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80β$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Information for Specific Infiniti Models
- P0037 2003 Infiniti G35 β HO2S12 Heater Control Circuit Low
- P0037 2004 Infiniti G35 β HO2S12 Heater Control Circuit Low
- P0037 2005 Infiniti G35 β HO2S12 Heater Control Circuit Low
- P0037 2006 Infiniti G35 β HO2S12 Heater Control Circuit Low
Frequently Asked Questions about P0037 Infiniti Code
1. What does the OBDII code P0037 mean on an Infiniti?
P0037 indicates a problem with the heater control circuit for the downstream oxygen sensor (HO2S12), specifically that the voltage is lower than expected.
2. What causes the P0037 code on an Infiniti?
Common causes include a faulty oxygen sensor, damaged wiring or connectors in the sensor's circuit, a blown fuse, or a malfunctioning engine control module (ECM).
3. What are the symptoms of the P0037 code on an Infiniti?
Symptoms may include an illuminated check engine light, reduced fuel efficiency, difficulty passing emissions tests, and sometimes poor engine performance.
4. Can I drive my Infiniti with the P0037 code?
While you can drive with this code, it is not recommended as it may lead to reduced fuel efficiency and potential long-term damage to the catalytic converter.
5. How do I fix the P0037 code on an Infiniti?
Repairs typically involve replacing the downstream oxygen sensor, repairing damaged wiring or connectors, checking fuses, or, in rare cases, replacing the ECM.
6. How do I diagnose the P0037 code on an Infiniti?
Diagnosis involves using a scan tool to confirm the code, visually inspecting the oxygen sensor and its wiring, testing the heater circuit for proper voltage, and checking the fuse for the sensor.
7. How much does it cost to fix the P0037 code on an Infiniti?
Replacing the oxygen sensor typically costs between $150 and $300, including parts and labor. Wiring or ECM repairs may vary depending on the extent of the issue.
8. What is the function of the HO2S12 sensor on an Infiniti?
The HO2S12 sensor monitors the oxygen levels in the exhaust after the catalytic converter and helps the ECM optimize fuel mixture and emissions.
9. Can a bad oxygen sensor cause the P0037 code on an Infiniti?
Yes, a faulty downstream oxygen sensor is one of the most common reasons for this code to appear.
10. Is a special tool needed to fix the P0037 code on an Infiniti?
Yes, you may need an OBDII scan tool for diagnosis and an oxygen sensor socket for sensor removal and replacement.
Discuss the causes and fixes for P0037 Infiniti OBDII Code
-
The sensor 2 is on the right side (passenger side) of the vehicle, on the exhaust system after the catalytic converter.
-
For the Heated Oxygen Sensor (H2OS) Bank 1 Sensor 2, the fuse is in the IPDM (Fuse box behind the battery). The fuse is the #85

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