Quick Answer
P0684 means: P0684 is a trouble code indicating an issue with the engine control module power relay circuit.
Can I drive with P0684? It is advisable to address this issue immediately, as it can lead to engine failure or performance problems.
Common Questions
What does P0684 mean and how does it affect my car?
P0684 indicates a problem with the engine control module power relay circuit, affecting your car's ability to start and run reliably. If ignored, it can lead to poor engine performance and potentially more severe issues.
What are the most common causes of P0684 and how much does it cost to fix?
The most common causes include a faulty ECM power relay, damaged wiring, or a blown fuse. Repair costs can range from $50 for a relay replacement to $1,500 for an ECM replacement, depending on the issue.
Can I drive my car with P0684 or should I stop immediately?
It's best to avoid driving your vehicle with this code as it may lead to stalling or failure to start, potentially leaving you stranded.
How can I diagnose P0684 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for OBD2 codes, view freeze frame data, and perform system tests to pinpoint the issue related to P0684.
What vehicles are most commonly affected by P0684?
Common vehicles affected by P0684 include the 2004-2010 Ford F-150, 2006-2011 Dodge Charger, and 2008-2014 Jeep Wrangler, among others.
How can I prevent P0684 from happening again?
Regularly inspect your vehicle's electrical system, including the relay and wiring, and ensure timely maintenance to prevent future occurrences of P0684.
What is P0684?
The diagnostic trouble code P0684 indicates a problem with the engine control module (ECM) power relay circuit. This issue is often related to the relay responsible for providing power to the ECM, which is crucial for engine management and performance. When the ECM does not receive sufficient power, it can lead to various complications, including failure to start, poor engine performance, and increased emissions. This code is commonly found in various models, including the 2004-2010 Ford F-150, 2006-2011 Dodge Charger, and 2008-2014 Jeep Wrangler. In most cases, the problem can stem from a faulty relay, damaged wiring, or even a blown fuse. If you encounter this code, it's essential to address it promptly, as ignoring it could lead to more severe engine issues or complete vehicle failure. The symptoms may range from intermittent stalling to a complete inability to start the vehicle, making it critical for car owners to understand the implications of this code and take action accordingly.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0684 is present:
- Check engine light stays on constantly, indicating an ongoing issue that needs immediate attention.
- Engine hesitates or stalls during acceleration, causing a lack of power when you need it the most.
- Fuel economy decreased by 10-15%, leading to higher fuel costs and increased emissions.
- Difficulty starting the engine, which may require multiple attempts to get the vehicle running.
- Inconsistent engine performance, where the vehicle may run smoothly one moment and then suddenly lose power.
Possible Causes
Most common causes of P0684 (ordered by frequency):
- The most common cause of P0684 is a faulty ECM power relay, which can have a likelihood of around 60%. This relay may fail due to wear and tear or electrical issues.
- Another potential cause is damaged wiring or connectors in the relay circuit, which can lead to intermittent power supply issues. Regular inspections can help prevent this.
- A blown fuse in the relay circuit can also trigger this code, though this is less common. Checking the fuse box can often reveal this issue quickly.
- Less common but serious causes include a malfunctioning ECM itself, which may require replacement if diagnosed.
- A rare cause could be a software issue within the ECM, which may necessitate a software update or reprogramming.
P0684 Repair Costs
Cost Breakdown by Repair Type
ECM Power Relay Replacement
Replacing the faulty ECM power relay is a straightforward fix that usually resolves the P0684 issue.
- Total: $50 - $150
- Success rate: 85%
Wiring and Connector Repair
Repairing any damaged wiring or connectors in the relay circuit to restore proper function.
- Total: $100 - $300
- Success rate: 75%
ECM Replacement
In rare cases, replacing the ECM may be necessary if it is found to be faulty.
- Total: $500 - $1,500
- Success rate: 90%
Money-Saving Tips for P0684
- 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 P0684 Diagnosis Process
Follow these systematic steps to accurately diagnose P0684. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components, starting with the relay and fuses (20-30 minutes)
Step 3: Component testing - Use a multimeter or specific diagnostic tools to test suspected components, starting with the relay and fuses (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes)
Step 4: System function test - Verify proper operation after repairs and clear codes using the GeekOBD APP (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure no codes reappear (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success and ensure no codes 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: ECM Power Relay Replacement on a 2007 Ford F-150
Vehicle: 2007 Ford F-150, 120,000 miles
Problem: Customer reported check engine light and intermittent stalling.
Diagnosis: Diagnostic scan revealed P0684. Visual inspection showed a burnt relay.
Solution: Replaced the ECM power relay, cleared codes, and verified operation.
Cost: $75 (parts and labor)
Result: Customer reported smooth performance after repair with no recurrence of symptoms.
Case Study 2: Wiring Repair on a 2010 Dodge Charger
Vehicle: 2010 Dodge Charger, 90,000 miles
Problem: Customer experienced difficulty starting and a persistent check engine light.
Diagnosis: P0684 was triggered due to damaged wiring in the relay circuit.
Solution: Repaired wiring and replaced the blown fuse, then cleared the codes.
Cost: $150 (parts and labor)
Result: Vehicle started reliably, and the check engine light remained off after repair.