Testing Crank Sensor on Autel MX808: A Comprehensive Guide

The Autel MX808 diagnostic tool is a versatile device used by automotive technicians and enthusiasts to diagnose and repair vehicle issues. In this comprehensive guide from CARDIAGTECH.NET, we will focus on how to use the Autel MX808 for testing the crank sensor. Understanding the crank sensor function and how to test it using your Autel MX808 enhances your diagnostic skills, streamlines your repair work, and helps maintain optimal engine performance.

1. Understanding the Crank Sensor

The crankshaft position (CKP) sensor, often referred to as the crank sensor, is a vital component in an internal combustion engine’s electronic control system. It monitors the position and rotational speed of the crankshaft. This information is essential for the engine control unit (ECU) to manage ignition timing, fuel injection, and other critical engine functions. According to Bosch, a leading automotive supplier, accurate crank sensor readings are crucial for efficient engine operation.

1.1. Function and Importance

The crank sensor plays a pivotal role in:

Ignition Timing: The ECU uses the crank sensor signal to determine when to fire the spark plugs.
Fuel Injection: Knowing the crankshaft position helps the ECU time fuel injection events.
Engine Speed (RPM): The sensor provides data on the engine’s rotational speed.
Diagnostic Trouble Codes (DTCs): Problems with the crank sensor often trigger DTCs, aiding in diagnosis.

1.2. Common Symptoms of a Failing Crank Sensor

When a crank sensor fails or becomes erratic, it can lead to various engine performance issues. Recognizing these symptoms is the first step in effective diagnostics. Here are some common indicators:

Engine Stalling: The engine may stall unexpectedly, especially when it gets hot.
Hard Starting: Difficulty starting the engine, particularly when it’s cold or warm.
Check Engine Light: Illumination of the check engine light with codes related to the crank sensor.
Rough Idling: The engine may idle roughly or unevenly.
Reduced Fuel Efficiency: Decreased mileage due to improper combustion.
Engine Misfires: Irregular firing of cylinders can result in misfires.
No Start Condition: In severe cases, the engine may fail to start at all.

Alt text: Common symptoms of a failing crankshaft position sensor, including stalling, hard starting, check engine light, rough idling, reduced fuel efficiency, engine misfires, and no-start condition.

2. Preparing for the Test

Before diving into the testing procedure, it’s essential to gather the necessary tools and information. Proper preparation ensures a smooth and accurate diagnostic process.

2.1. Gathering Necessary Tools

To effectively test a crank sensor using the Autel MX808, you’ll need the following:

Autel MX808 Diagnostic Tool: Ensure it is updated with the latest software.
OBDII Cable: To connect the MX808 to the vehicle’s diagnostic port.
Vehicle’s Repair Manual: Provides specific information about the crank sensor location and testing procedures for your vehicle.
Multimeter (Optional): For additional testing, such as checking voltage and resistance.
Wiring Diagram (Optional): Helps in identifying the correct wires and their functions.

2.2. Vehicle Information and Location of the Crank Sensor

Accurate vehicle information is crucial for a successful test. Knowing the make, model, and year of the vehicle allows you to access the correct diagnostic protocols and sensor specifications.

Locate the Crank Sensor: The crank sensor is typically located near the crankshaft pulley or flywheel. Consult your vehicle’s repair manual for the exact location.
Access Repair Information: Use online databases like ALLDATA or Mitchell OnDemand to find specific repair information and diagrams for your vehicle.
Record Vehicle Details: Keep a record of the vehicle’s VIN, engine type, and any relevant service history.

3. Step-by-Step Guide to Testing Crank Sensor on Autel MX808

Testing the crank sensor with an Autel MX808 involves a systematic approach to ensure accurate results. Follow these steps to effectively diagnose the crank sensor.

3.1. Connecting the Autel MX808

Locate the OBDII Port: Typically found under the dashboard on the driver’s side.
Connect the MX808: Plug the OBDII cable into the vehicle’s port and the other end into the MX808.
Power On the MX808: Turn on the MX808 and wait for it to boot up.

Alt text: Connecting the Autel MX808 scan tool to the vehicle’s OBDII port located under the dashboard.

3.2. Identifying the Vehicle

Auto VIN Detection: On the MX808, select “Auto VIN” to automatically identify the vehicle.
Manual Input: If Auto VIN fails, manually enter the vehicle’s make, model, and year.
Confirm Vehicle Details: Ensure the information is correct before proceeding.

3.3. Accessing Engine Control Module (ECM)

Select Diagnostics: From the main menu, choose “Diagnostics.”
Select Control Unit: Navigate to “Powertrain” or “Engine Control Module (ECM).”
Confirm ECM Selection: Ensure you’ve selected the correct control module for the engine.

3.4. Reading Diagnostic Trouble Codes (DTCs)

Select “Read Codes”: In the ECM menu, choose the option to read diagnostic trouble codes.
Record DTCs: Note any codes related to the crank sensor, such as P0335 (Crankshaft Position Sensor A Circuit Malfunction) or P0336 (Crankshaft Position Sensor A Circuit Range/Performance).
Clear Codes (Optional): If desired, clear the codes and recheck after running the engine to see if they reappear.

3.5. Viewing Live Data

Select “Live Data”: In the ECM menu, choose the option to view live data.
Select Relevant Parameters: Look for parameters related to the crank sensor, such as “Crankshaft Position Sensor RPM” or “CKP Sensor Signal.”
Monitor Data: Start the engine and observe the live data. The RPM reading should be stable and consistent with the engine’s actual speed.

3.6. Analyzing the Data

Check for Signal Dropouts: Watch for any sudden drops or inconsistencies in the CKP sensor signal.
Compare to Specifications: Refer to the vehicle’s repair manual for the expected range of values.
Evaluate Signal Pattern: A healthy crank sensor should produce a consistent and regular signal pattern.

3.7. Performing Active Tests (If Available)

Access Active Tests: In the ECM menu, look for an option like “Active Tests” or “Component Tests.”
Select Crank Sensor Test: If available, select a test specifically designed for the crank sensor.
Follow On-Screen Instructions: The MX808 will guide you through the test, which may involve monitoring the sensor’s response to induced changes.

3.8. Interpreting the Results

Consistent Signal: If the live data shows a stable and accurate signal, and there are no relevant DTCs, the crank sensor is likely functioning correctly.
Erratic Signal: If the live data shows signal dropouts, inconsistencies, or if relevant DTCs are present, the crank sensor may be faulty.
No Signal: If there is no signal at all, the crank sensor may be completely dead or there may be a wiring issue.

Alt text: Reading live data on the Autel MX808, showing real-time sensor values for diagnosing engine performance.

4. Advanced Troubleshooting

If the initial tests indicate a problem with the crank sensor, further troubleshooting steps may be necessary to pinpoint the exact cause.

4.1. Checking the Wiring and Connections

Inspect Connectors: Check the crank sensor’s connector for corrosion, damage, or loose connections.
Check Wiring: Examine the wiring harness leading to the sensor for any signs of damage, such as cuts, abrasions, or melted insulation.
Test Continuity: Use a multimeter to check the continuity of the wires between the sensor and the ECM. Refer to the wiring diagram for the correct pins.

4.2. Using a Multimeter

Check Voltage Supply: Use a multimeter to check for the correct voltage supply to the crank sensor. Refer to the vehicle’s repair manual for the specified voltage.
Check Ground: Ensure the sensor has a good ground connection.
Measure Resistance: Measure the resistance of the sensor. Compare the reading to the specifications in the repair manual.

4.3. Understanding Sensor Types

Hall Effect Sensors: These sensors use a magnetic field to generate a signal. They typically have three wires: power, ground, and signal.
Variable Reluctance Sensors: These sensors generate a signal based on the change in magnetic reluctance. They usually have two wires.

4.4. Checking for Interference

EMI: Electromagnetic interference can sometimes affect the crank sensor signal. Ensure there are no nearby sources of EMI, such as faulty ignition components or aftermarket electronics.
Shielding: Check that the sensor’s wiring is properly shielded to prevent interference.

4.5. Verifying the Flywheel/Crankshaft Pulley

Inspect Tone Ring: Examine the tone ring on the flywheel or crankshaft pulley for damage, missing teeth, or excessive rust.
Check Alignment: Ensure the sensor is properly aligned with the tone ring.

5. Replacing the Crank Sensor

If the troubleshooting steps confirm that the crank sensor is faulty, replacement is necessary. Follow these steps to safely and effectively replace the crank sensor.

5.1. Safety Precautions

Disconnect the Battery: Before starting any work, disconnect the negative terminal of the battery to prevent electrical shorts.
Allow Engine to Cool: Ensure the engine is cool to avoid burns.
Use Proper Tools: Use the correct tools for the job to prevent damage to the vehicle.

5.2. Removal Process

Locate the Sensor: Refer to the vehicle’s repair manual for the exact location of the crank sensor.
Disconnect the Connector: Disconnect the electrical connector from the sensor.
Remove Mounting Bolts: Remove the bolts or screws that secure the sensor in place.
Extract the Sensor: Carefully remove the sensor from its mounting location.

5.3. Installation Process

Install New Sensor: Install the new crank sensor in the mounting location.
Secure Mounting Bolts: Tighten the mounting bolts to the specified torque.
Connect Electrical Connector: Reconnect the electrical connector to the sensor.
Verify Installation: Ensure the sensor is properly seated and the connector is securely attached.

5.4. Post-Replacement Procedures

Reconnect Battery: Reconnect the negative terminal of the battery.
Clear DTCs: Use the Autel MX808 to clear any DTCs related to the crank sensor.
Verify Operation: Start the engine and verify that it runs smoothly and that there are no new DTCs.
Perform a Crankshaft Position System Variation Learn (If Required): Some vehicles require a crankshaft position system variation learn procedure after replacing the crank sensor. Consult the vehicle’s repair manual for specific instructions.

6. Benefits of Using Autel MX808 for Crank Sensor Testing

The Autel MX808 offers several advantages for testing and diagnosing crank sensors, making it an invaluable tool for automotive technicians and enthusiasts.

6.1. Accuracy and Efficiency

Precise Data: The MX808 provides accurate and real-time data, allowing for precise diagnosis of crank sensor issues.
Fast Diagnosis: The tool quickly retrieves DTCs and live data, reducing diagnostic time.

6.2. User-Friendly Interface

Intuitive Navigation: The MX808 features an easy-to-use interface, making it accessible for both novice and experienced users.
Clear Display: The 7-inch touchscreen provides a clear and detailed display of diagnostic information.

6.3. Comprehensive Vehicle Coverage

Wide Range of Vehicles: The MX808 supports a wide range of vehicle makes and models, ensuring compatibility with most vehicles.
Regular Updates: Autel provides regular software updates, keeping the tool up-to-date with the latest vehicle models and diagnostic protocols.

6.4. Additional Features

Active Tests: The MX808 supports active tests, allowing technicians to control various engine components for diagnostic purposes.
Data Logging: The tool can log and save data, which can be useful for analyzing intermittent issues.

7. Real-World Examples and Case Studies

To illustrate the effectiveness of using the Autel MX808 for crank sensor testing, let’s consider a couple of real-world examples.

7.1. Case Study 1: Diagnosing Intermittent Stalling

Vehicle: 2010 Honda Civic
Complaint: Intermittent stalling, especially when the engine is hot.
Diagnostic Steps:
1. Connected the Autel MX808 to the vehicle and read DTCs. Found a P0335 code (Crankshaft Position Sensor A Circuit Malfunction).
2. Viewed live data for the crank sensor. Noticed intermittent signal dropouts when the engine was hot.
3. Checked the wiring and connections. Found a corroded connector at the crank sensor.
Resolution: Cleaned the connector and applied dielectric grease. Cleared the DTCs and retested. The engine ran smoothly, and the stalling issue was resolved.

7.2. Case Study 2: Resolving a No-Start Condition

Vehicle: 2015 Ford F-150
Complaint: No-start condition.
Diagnostic Steps:
1. Connected the Autel MX808 to the vehicle and read DTCs. Found a P0336 code (Crankshaft Position Sensor A Circuit Range/Performance).
2. Viewed live data for the crank sensor. Found no signal at all.
3. Checked the wiring and connections. Found a broken wire leading to the crank sensor.
Resolution: Repaired the broken wire. Cleared the DTCs and retested. The engine started immediately, and the no-start condition was resolved.

8. Tips and Best Practices

To ensure accurate and reliable crank sensor testing with the Autel MX808, keep the following tips and best practices in mind.

8.1. Keep the MX808 Updated

Regular Updates: Regularly update the MX808 software to ensure compatibility with the latest vehicle models and diagnostic protocols.
Wi-Fi Connection: Connect the MX808 to a stable Wi-Fi network for seamless updates.

8.2. Use Reliable Repair Information

Vehicle-Specific Data: Always refer to the vehicle’s repair manual for accurate specifications and procedures.
Online Resources: Utilize online databases like ALLDATA or Mitchell OnDemand for comprehensive repair information.

8.3. Perform Thorough Visual Inspections

Check for Damage: Always perform a thorough visual inspection of the crank sensor, wiring, and connectors before conducting any tests.
Look for Corrosion: Pay close attention to connectors for signs of corrosion or damage.

8.4. Use Proper Testing Techniques

Follow Procedures: Follow the testing procedures outlined in the vehicle’s repair manual and the Autel MX808 user guide.
Accurate Data Interpretation: Ensure you understand how to interpret the data provided by the MX808.

8.5. Document Your Findings

Record DTCs: Always record any DTCs found during the diagnostic process.
Take Notes: Take detailed notes on your findings, including live data readings, test results, and any repairs performed.

9. Why Choose CARDIAGTECH.NET for Your Diagnostic Tool Needs

When it comes to purchasing diagnostic tools like the Autel MX808, choosing the right supplier is crucial. CARDIAGTECH.NET stands out as a reliable and trustworthy provider of automotive diagnostic solutions.

9.1. Expertise and Experience

Industry Knowledge: CARDIAGTECH.NET has extensive knowledge and experience in the automotive diagnostic industry.
Expert Support: We offer expert technical support to help you get the most out of your diagnostic tools.

9.2. Wide Range of Products

Comprehensive Selection: We offer a comprehensive selection of diagnostic tools and equipment to meet your needs.
Quality Products: We only sell high-quality products from reputable brands like Autel.

9.3. Competitive Pricing

Affordable Solutions: We offer competitive pricing on all of our products, making advanced diagnostic tools accessible to technicians and enthusiasts.
Value for Money: We provide excellent value for money, combining quality products with expert support.

9.4. Customer Satisfaction

Dedicated Support: We are dedicated to providing excellent customer service and support.
Customer Reviews: Our positive customer reviews speak to our commitment to customer satisfaction.

10. Frequently Asked Questions (FAQs)

10.1. What is a Crank Sensor?

The crank sensor, or crankshaft position sensor, monitors the position and rotational speed of the crankshaft. It is essential for ignition timing, fuel injection, and engine speed management.

10.2. Where is the Crank Sensor Located?

The crank sensor is typically located near the crankshaft pulley or flywheel. Consult your vehicle’s repair manual for the exact location.

10.3. What are the Symptoms of a Bad Crank Sensor?

Common symptoms include engine stalling, hard starting, check engine light, rough idling, reduced fuel efficiency, and engine misfires.

10.4. Can I Test a Crank Sensor with a Multimeter?

Yes, you can use a multimeter to check the voltage supply, ground connection, and resistance of the crank sensor.

10.5. What is the P0335 Code?

P0335 is a diagnostic trouble code that indicates a malfunction in the crankshaft position sensor A circuit.

10.6. What is the P0336 Code?

P0336 is a diagnostic trouble code that indicates a range or performance problem in the crankshaft position sensor A circuit.

10.7. How Often Should I Replace the Crank Sensor?

The crank sensor should be replaced when it fails or shows signs of erratic behavior. There is no set replacement interval.

10.8. Can I Drive with a Bad Crank Sensor?

It is not recommended to drive with a bad crank sensor, as it can cause engine stalling and other performance issues.

10.9. How Do I Clear DTCs with the Autel MX808?

Connect the MX808 to the vehicle, select “Diagnostics,” choose the appropriate control module, select “Read Codes,” and then select “Erase Codes.”

10.10. Where Can I Purchase the Autel MX808?

You can purchase the Autel MX808 from CARDIAGTECH.NET, a trusted supplier of automotive diagnostic tools.

Conclusion

Testing the crank sensor with an Autel MX808 is a straightforward process that can save you time and money by accurately diagnosing engine issues. By following the steps outlined in this guide, you can effectively use the MX808 to troubleshoot crank sensor problems and ensure optimal engine performance. Remember to rely on CARDIAGTECH.NET for all your diagnostic tool needs, where you’ll find quality products and expert support to keep your vehicles running smoothly. For more information or assistance, contact CARDIAGTECH.NET at 276 Reock St, City of Orange, NJ 07050, United States, Whatsapp: +1 (641) 206-8880, or visit our website at CARDIAGTECH.NET. Let us help you keep your vehicles in top condition with our comprehensive range of diagnostic solutions.

Ready to experience the benefits of the Autel MX808 and other top-quality diagnostic tools? Contact CARDIAGTECH.NET today for expert advice and support. Don’t let automotive issues slow you down – enhance your diagnostic capabilities with our advanced tools and keep your vehicles running at their best. Call us now or visit CARDIAGTECH.NET to explore our full range of solutions.