P2251 Acura Code - Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage
Quick Answer
The rear air/fuel ratio (A/F) sensor (bank 1, sensor 1) is installed in the exhaust manifold and detects oxygen content in the exhaust gas. Common causes include Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 harness is open or shorted, Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 circuit poor electrical connection, Faulty Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1. 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
- P2251 Acura indicates Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 VS Line High Voltage.
- Common causes
- Common causes include Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 harness is open or shorted, Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 circuit poor electrical connection, Faulty Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1.
- 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 P2251 Acura Description
What are the Possible Causes of the DTC P2251 Acura?
- Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 harness is open or shorted
- Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1
How to Fix the DTC P2251 Acura?
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.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P2251 Acura 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 P2251 Acura Code
1. What does the OBDII code P2251 mean on an Acura?
P2251 indicates an issue with the Rear Air/Fuel Ratio Sensor (Bank 1, Sensor 1) where the Voltage Signal Line is reporting abnormally high voltage.
2. What are common symptoms of the P2251 code in an Acura?
Symptoms may include a check engine light, poor fuel efficiency, rough idling, reduced engine performance, or failed emissions tests.
3. What causes the P2251 code to trigger in an Acura?
Common causes include a faulty air/fuel ratio sensor, damaged sensor wiring, a short circuit, corroded electrical connectors, or issues with the engine control module (ECM).
4. How do I diagnose the P2251 code on my Acura?
Start by using an OBDII scanner to confirm the code, inspect the air/fuel ratio sensor and its wiring for damage, and check for continuity or shorts in the sensor circuit.
5. Can I drive my Acura with a P2251 code?
Driving with a P2251 code is not recommended as it may lead to increased emissions, poor fuel economy, and potential damage to the catalytic converter.
6. How do I fix the P2251 code on an Acura?
Repairs may involve replacing the air/fuel ratio sensor, repairing or replacing damaged wiring, cleaning corroded connectors, or reprogramming the ECM if needed.
7. How much does it cost to repair the P2251 code on an Acura?
The cost can vary, but replacing an air/fuel ratio sensor typically costs $200–$400, including parts and labor. Wiring repairs may cost less depending on the extent of damage.
8. Is the P2251 code specific to one sensor on an Acura?
Yes, it specifically refers to the Rear Air/Fuel Ratio Sensor for Bank 1, which monitors the air-fuel mixture for the engine's first cylinder bank.
9. Can a bad oxygen sensor cause the P2251 code on an Acura?
Yes, the air/fuel ratio sensor (a type of oxygen sensor) may fail and cause the P2251 code to trigger.
10. Do I need special tools to fix the P2251 code on my Acura?
Yes, you may need an OBDII scanner, a multimeter for electrical testing, and a sensor socket to remove and replace the air/fuel ratio sensor.
Discuss the causes and fixes for P2251 Acura OBDII Code
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how much doest it cost to replace? and if not fixed what will happen to the vehicle will it cause damage??
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What model is your Acura? The price depends where you buy the sensor and if you use factory or aftermarket parts. A new factory sensor could cost you around $200. If you don't replace the sensor your Acura will fail the smog test.
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Acura 202 I got p0134 and p2251 and the ABS night on dawn and check Engine light the too code can cause ABS nd check Engine light
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You have to replace the Rear Air/Fuel Ratio Sensor Bank 1 Sensor 1. The ABS light is a different problem. You have to get the ABS code to find the problem.
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There is not Acura Jeep, is either Acura or Jeep.
Here is the location for the Acura MDX, I hope that helps.
Click here to enlarge image -
Auto hv replace the sensor bank 1 sensor 1 the check Engine is still on and I scan the acura MDX 2004 again this is what I got p0134 02 circuit No Activity Detected (bank1, sensor 1) that is what I got again pls what can I do now
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