Quick Answer
C0844 means: C0844 indicates a problem with the Vehicle Speed Sensor or related traction control systems.
Can I drive with C0844? Immediate attention is recommended to maintain vehicle safety and performance.
Common Questions
What does C0844 mean and how does it affect my car?
The C0844 code indicates a malfunction with the Vehicle Speed Sensor, impacting the vehicle's traction control and stability systems. This can lead to reduced safety and control, particularly in adverse driving conditions.
What are the most common causes of C0844 and how much does it cost to fix?
Common causes include a faulty Vehicle Speed Sensor, damaged wiring, and potentially a malfunctioning PCM. Repair costs vary from $100 for wiring repairs to $600 for PCM replacement.
Can I drive my car with C0844 or should I stop immediately?
While it's possible to drive with this code, it's not recommended. Ignoring it can lead to safety issues, especially in slippery conditions. Immediate attention is advised.
How can I diagnose C0844 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for codes and view freeze frame data to understand when the fault occurred. This insight can guide your troubleshooting efforts effectively.
What vehicles are most commonly affected by C0844?
The C0844 code is commonly found in 2015-2019 Chevrolet and GMC models, including the Silverado, Sierra, Tahoe, and Suburban. Be sure to check for any recalls related to these issues.
How can I prevent C0844 from happening again?
Regular maintenance and inspections of the vehicle's electrical systems and components can help prevent C0844. Ensure that wiring and connectors are in good condition, and consider periodic diagnostics with the GeekOBD APP.
What is C0844?
The DTC C0844 trouble code is a diagnostic trouble code that indicates an issue with the Vehicle Speed Sensor (VSS) or related components in your vehicle's traction control or stability system. This code is often found in various General Motors models, especially Chevrolet and GMC trucks and SUVs manufactured between 2015 and 2019. When the C0844 code is triggered, it typically means that the powertrain control module (PCM) has detected an inconsistency in the data received from the VSS, which can lead to a decrease in vehicle stability and traction control functionality. In practical terms, this could manifest as erratic behavior of the vehicle's anti-lock braking system (ABS) or traction control, causing safety concerns while driving. For car owners, it's essential to recognize that ignoring this code could lead to more significant issues down the road, including compromised safety systems and potentially costly repairs. If you find this code appearing in your vehicle's OBD2 system, addressing it promptly can help maintain your car's performance and safety features.
System: C - Chassis (ABS, Steering, Suspension)
Symptoms
Common symptoms when C0844 is present:
- The check engine light may illuminate and stay on, indicating a fault in the vehicle's systems.
- You may experience a loss of traction control, especially during acceleration or in slippery conditions, leading to a reduced sense of control while driving.
- The anti-lock braking system (ABS) may behave inconsistently, resulting in longer stopping distances and unpredictable braking response.
- You might notice a decrease in fuel economy, potentially between 5-10%, as the vehicle compensates for the sensor's inaccuracies.
- Unusual noises from the traction control system may occur, indicating it is attempting to compensate for the reported issues.
Possible Causes
Most common causes of C0844 (ordered by frequency):
- The most common cause of the C0844 code is a faulty Vehicle Speed Sensor (VSS), which can occur in about 70% of cases. This sensor is crucial for providing accurate speed data to the PCM.
- Another potential cause is damaged wiring or connectors related to the VSS. Corrosion or frayed wires can lead to communication issues, accounting for approximately 20% of cases.
- A third cause could be a malfunctioning PCM, which might misinterpret the data from the VSS, although this is less common. Preventive measures include regular vehicle diagnostics to catch issues early.
- Less commonly, issues with the ABS module can trigger this code. If the ABS module is malfunctioning, it can disrupt the entire system, leading to safety concerns.
- In rare cases, software glitches within the vehicle's electronic systems might cause false readings, leading to the C0844 code being set.
C0844 Repair Costs
Cost Breakdown by Repair Type
Vehicle Speed Sensor Replacement
Replacing the faulty Vehicle Speed Sensor with a new OEM part.
- Total: $150 - $300
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring and connectors associated with the VSS.
- Total: $100 - $200
- Success rate: 75%
PCM Reprogramming
Reprogramming or replacing the PCM if it is diagnosed as faulty.
- Total: $300 - $600
- Success rate: 60%
Money-Saving Tips for C0844
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional C0844 Diagnosis Process
Follow these systematic steps to accurately diagnose C0844. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check the wiring and connectors for the Vehicle Speed Sensor for any visible damage or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check the wiring and connectors for the Vehicle Speed Sensor for any visible damage or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Use the GeekOBD APP to retrieve all trouble codes and freeze frame data
Step 2: OBD2 scan with GeekOBD APP - Use the GeekOBD APP to retrieve all trouble codes and freeze frame data. This helps understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Utilize a multimeter or appropriate diagnostic tools to test the VSS for proper functionality and resistance (20-30 minutes)
Step 3: Component testing - Utilize a multimeter or appropriate diagnostic tools to test the VSS for proper functionality and resistance (20-30 minutes).
Step 4: Step 4: System function test - After repairs or replacements, verify the proper operation of the VSS and clear the codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - After repairs or replacements, verify the proper operation of the VSS and clear the codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to ensure all systems function correctly and confirm that the code does not reappear (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to ensure all systems function correctly and confirm that the code does not reappear (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: 2018 Chevrolet Silverado - C0844 Diagnosis and Repair
Vehicle: 2018 Chevrolet Silverado 1500, 50,000 miles
Problem: Customer reported that the check engine light was illuminated and experienced traction control issues.
Diagnosis: After scanning with the GeekOBD APP, C0844 was confirmed. A visual inspection revealed damaged wiring leading to the VSS.
Solution: Repaired the damaged wiring and replaced the Vehicle Speed Sensor. Cleared the codes and performed a road test.
Cost: $250 (including parts and labor)
Result: The repair resolved the issue, and the check engine light remained off after multiple test drives.
Case Study 2: 2016 GMC Sierra - C0844 Code Troubleshooting
Vehicle: 2016 GMC Sierra 2500HD, 75,000 miles
Problem: Customer complained of inconsistent ABS performance and illuminated check engine light.
Diagnosis: After running diagnostics with the GeekOBD APP, the C0844 code was present. The VSS tested out of specification.
Solution: Replaced the Vehicle Speed Sensor and reprogrammed the PCM. Verified functionality through a road test.
Cost: $400 (specific cost breakdown included VSS and labor)
Result: The vehicle's ABS function returned to normal, and the customer reported improved stability.