Speed Control Lamp Control Circuit
The P0649 code means the vehicle's onboard diagnostic system has detected: Speed Control Lamp Control Circuit. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $50 - $500 (parts and labor)
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What Are the Symptoms of P0649?
- Check Engine Light on
- Cruise control indicator light malfunction
- Reduced system performance
- Warning indicators on dashboard
What Causes P0649? (Most Likely First)
- Faulty speed control lamp circuit Very High
- Wiring damage or corrosion in the circuit High
- Poor electrical connection at module or component Moderate
- ECM or control module internal failure Low
Can I Still Drive with P0649?
Yes, but fix soon. P0649 is rated low severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring the light.
Frequently Asked Questions
What does P0649 mean?
P0649 indicates a fault in the speed control lamp control circuit. This is an electronic control system code that affects the ECM's ability to manage the associated component or system.
Is P0649 a serious code?
This is a low-priority code that does not typically affect drivability but should be diagnosed when convenient.
Can a low battery cause ECM-related codes?
Yes. Low battery voltage can cause various ECM and module communication codes. Always verify the battery is fully charged and the charging system is working before diagnosing electronic control module codes.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0649?
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Use a scan tool to read data related to Speed Control Lamp Control
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Inspect all related wiring, connectors, and grounds for damage, corrosion, or loose connections
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Measure circuit voltage, resistance, and continuity to identify the fault type
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Check for technical service bulletins related to this code for your specific vehicle
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Which Vehicles Commonly Get P0649?
- 2008-2018 Ford F-150
- 2010-2020 Toyota Camry
- 2009-2019 Honda Accord
- 2011-2020 Chevrolet Silverado
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