P0686 2015 GMC Sierra Code - Engine Control Module Power Relay Control Circuit Low
Quick Answer
The P0686 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates that there is a malfunction in the engine control module (ECM) power relay control circuit, specifically that the voltage is lower than the expected range. Common causes include Faulty ECM power relay, Damaged wiring or connectors in the power relay circuit, Blown fuse related to the ECM power relay. 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
- P0686 2015 GMC Sierra indicates Engine Control Module Power Relay Control Circuit Low.
- Common causes
- Common causes include Faulty ECM power relay, Damaged wiring or connectors in the power relay circuit, Blown fuse related to the ECM power relay.
- 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 P0686 2015 GMC Sierra Description
The P0686 diagnostic trouble code (DTC) for a 2015 GMC Sierra indicates that there is a malfunction in the engine control module (ECM) power relay control circuit, specifically that the voltage is lower than the expected range. The ECM power relay is responsible for supplying power to the ECM, which is the brain of the vehicle's engine management system. The ECM controls various functions such as fuel injection, ignition timing, and emissions control. When the power relay control circuit is low, it can lead to a variety of issues that affect the vehicle's performance and drivability.
Common Causes of P0686 2015 GMC Sierra
- Faulty ECM power relay
- Damaged wiring or connectors in the power relay circuit
- Blown fuse related to the ECM power relay
- Malfunctioning ECM
- Corrosion or poor connections in the power relay circuit
Symptoms of P0686 2015 GMC Sierra
- Check Engine Light illuminated on the dashboard
- Poor fuel efficiency
- Rough idling or stalling
- Difficulty starting the engine
- Vehicle going into limp mode
How to Fix P0686 2015 GMC Sierra
- Begin by conducting a thorough inspection of the ECM power relay, wiring, and connectors for any visible damage or corrosion.
- Test the ECM power relay using a multimeter to check for proper voltage and continuity.
- Check the fuses related to the ECM power relay to ensure they are not blown.
- If the ECM power relay is faulty, replace it with a new one following the manufacturer's guidelines.
- Clear the DTC and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P0686 2015 GMC Sierra
The typical repair costs for addressing the P0686 code on a 2015 GMC Sierra can range from $150 to $300. This estimate includes the cost of a new ECM power relay, any necessary wiring repairs, and labor. Keep in mind that specific diagnosis time and labor rates at auto repair shops can vary based on factors such as location, vehicle make and model, and engine type. It's advisable to check local rates for a more precise estimate.
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Frequently Asked Questions about P0686 2015 GMC Sierra Code
1. What does OBDII code P0686 mean on a 2015 GMC Sierra?
P0686 indicates a problem with the Engine Control Module (ECM) Power Relay Control Circuit being too low, meaning the ECM may not be receiving sufficient power.
2. What are the common symptoms of code P0686 on a 2015 GMC Sierra?
Common symptoms include difficulty starting the engine, engine stalling, reduced fuel efficiency, and illuminated check engine light.
3. What causes code P0686 on a 2015 GMC Sierra?
Possible causes include a faulty ECM power relay, damaged wiring or connectors in the relay circuit, a blown fuse, or a malfunctioning ECM.
4. Can I drive my 2015 GMC Sierra with code P0686 active?
Driving with code P0686 is not recommended, as it can lead to engine stalling or prevent the engine from starting, potentially causing unsafe driving conditions.
5. How is code P0686 diagnosed on a 2015 GMC Sierra?
A technician will use a scan tool to confirm the code, inspect the ECM power relay, check for damaged wiring or connectors, and test the power and ground circuits.
6. What repairs can fix code P0686 on a 2015 GMC Sierra?
Repairs may include replacing the ECM power relay, repairing damaged wiring or connectors, replacing a blown fuse, or, in rare cases, replacing the ECM itself.
7. How much does it cost to fix code P0686 on a 2015 GMC Sierra?
Repair costs vary depending on the issue but typically range from $50 to $300, with relay replacements being on the lower end and ECM replacements on the higher end.
8. Can a bad battery cause code P0686 on a 2015 GMC Sierra?
Yes, a weak or failing battery can cause low voltage in the ECM power relay circuit, triggering code P0686.
9. How can I prevent code P0686 from recurring on my 2015 GMC Sierra?
Regularly inspect the wiring and connections for corrosion or damage, ensure the battery is in good condition, and replace the ECM power relay if it shows signs of wear.
10. Will disconnecting the battery clear code P0686 on a 2015 GMC Sierra?
Disconnecting the battery may temporarily clear the code, but it won’t fix the underlying issue, and the code is likely to return until the problem is resolved.
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