OBD Code P0649
Speed Control Lamp Control Circuit
| Code | P0649 |
| Description | Speed Control Lamp Control Circuit |
| Possible Causes | Faulty cruise control indicator|Module issue |
| Symptoms | Cruise indicator light malfunction |
| System | Computer |
What Does P0649 Mean?
Speed Control Lamp Control Circuit. This diagnostic trouble code (DTC) is stored when the vehicle's onboard computer detects an issue with the computer.
Code Breakdown
P = Powertrain code
0 = Generic (SAE standard)
How to Fix P0649
Follow these diagnostic steps to identify and resolve the issue. Always start with the simplest checks before moving to more involved repairs.
- Check the affected bulb — replace if burned out.
- Inspect the bulb socket for corrosion or loose contacts.
- Check the wiring and connector to the affected light circuit.
- Test the light control module or body control module output to the circuit.
- Check related fuses and relays.
- For LED/HID headlamps, the ballast or driver module may need replacement.
- Clear codes and verify all lights function in all modes (headlights, turn signals, brake lights).
Note: These are general diagnostic guidelines. Some vehicles may have model-specific procedures. Always consult your vehicle's service manual for exact specifications and torque values. If you are not comfortable performing these steps, visit a qualified mechanic.
Frequently Asked Questions
Is P0649 serious?
P0649 is generally considered a low-severity code. While it should still be addressed, it is unlikely to cause immediate safety concerns. However, ignoring it long-term may lead to higher emissions or reduced fuel economy.
Can I clear P0649 myself?
You can clear any OBD-II code with a code scanner or by disconnecting the battery for 15-30 minutes. However, clearing the code without fixing the underlying problem will cause it to return, usually within one or two drive cycles. If the code triggered the check engine light, the light will come back on. Fix the root cause first, then clear the code.
How much does it cost to fix P0649?
Repair costs vary widely depending on the root cause. Some fixes are free (like tightening a gas cap) while others can cost several hundred dollars (like replacing a catalytic converter or oxygen sensor). A proper diagnosis with a professional scan tool, not just reading the code, is the first step to getting an accurate repair estimate. Many auto parts stores offer free code reading, but a thorough diagnosis usually requires a mechanic.