AutoCodes – Buick – P0251 Buick

P0251 Buick Code - Injection Pump Cam Sensor Circuit

Quick Answer

The optical sensor provides a pump cam signal to Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. Common causes include Faulty Injection Pump, Injection Pump harness is open or shorted, Injection Pump circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0251 Buick indicates Injection Pump Cam Sensor Circuit.
Common causes: Common causes include Faulty Injection Pump, Injection Pump harness is open or shorted, Injection Pump circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 325

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 21, 2022

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0251 Buick Description

The optical sensor provides a pump cam signal to Powertrain Control Module (PCM) by counting pulses on the sensor disk located in the injection pump. The pump cam is an important input by PCM for fuel control and timing. The test monitors the number of crankshaft position pulses that have occurred since the last cam pulse. Physical one-to-one correspondence between pump cam and crankshaft implies that if more crank pulses are detected than cam pulses, the cam pulses have been missing. The Diagnostic Trouble Code (DTC) will set when 8 consecutive cam pulses are missing, or an average of 8 cam pulses are missing.

OBDII Code P0251 Buick - Injection Pump Cam Sensor Circuit - AutoCodes.com — P0251 Buick Code - Injection Pump Cam Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC P0251 Buick?

Faulty Injection Pump
Injection Pump harness is open or shorted
Injection Pump circuit poor electrical connection
Faulty Powertrain Control Module (PCM)

How to Fix the DTC P0251 Buick?

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 P0251 Buick 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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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0251 Buick Code

1. What are the common symptoms of OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- Common symptoms include engine misfires, rough idling, loss of power, and difficulty starting the vehicle.

2. What can cause the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- The code P0251 is usually triggered by a faulty camshaft position sensor, wiring issues, or a malfunctioning injection pump.

3. How can I diagnose the OBDII code P0251 in my Buick related to the Injection Pump Cam Sensor Circuit?

- Diagnose the code by checking the camshaft position sensor for proper operation, inspecting the wiring for any damage, and testing the injection pump for functionality.

4. Can a faulty camshaft position sensor be repaired, or does it need to be replaced to fix the OBDII code P0251 in a Buick?

- In most cases, a faulty camshaft position sensor will need to be replaced to resolve the P0251 code and ensure proper engine performance.

5. Are there any DIY repair tips for addressing the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- DIY repair tips include checking and cleaning the sensor connections, inspecting the wiring harness for any breaks, and ensuring all connections are secure.

6. Will driving with the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit cause further damage to the vehicle?

- Continuing to drive with this code may result in poor engine performance, reduced fuel efficiency, and potential damage to other engine components.

7. How much does it typically cost to repair the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- The cost of repairing this code can vary depending on the exact cause of the issue, but it may range from $200 to $500 for parts and labor.

8. Can resetting the OBDII system clear the P0251 code in a Buick related to the Injection Pump Cam Sensor Circuit?

- Resetting the OBDII system may temporarily clear the code, but it is essential to diagnose and address the underlying issue to prevent the code from reappearing.

9. Are there any preventive maintenance steps to avoid encountering the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- Regularly inspecting and maintaining the camshaft position sensor, wiring connections, and injection pump can help prevent issues that lead to the P0251 code.

10. How long does it typically take to repair the OBDII code P0251 in a Buick related to the Injection Pump Cam Sensor Circuit?

- The repair time can vary depending on the exact cause of the code and the complexity of the repair, but it may take anywhere from 1 to 3 hours to address the issue.