P0656 - Engine Control Module (ECM) Power Supply Circuit Range/Performance Problem

Quick Answer

P0656 means: P0656 indicates a power supply issue in the ECM circuit.

Fix: Check and replace faulty components Cost: $800 - $1500 Time: 90-180 minutes

Can I drive with P0656? Immediate attention is required to prevent potential engine damage.

Common Questions

What does P0656 mean and how does it affect my car?

P0656 indicates a power supply problem in your car's ECM. This can lead to engine performance issues such as stalling or poor acceleration. If not addressed, it could cause more severe damage to the engine.

What are the most common causes of P0656 and how much does it cost to fix?

Common causes include a faulty power supply circuit and a failing ECM. Repair costs can range from $100 for wiring repairs to $1500 for ECM replacement.

Can I drive my car with P0656 or should I stop immediately?

Driving with a P0656 code is not advisable as it can lead to erratic engine behavior and potential engine damage. It's best to stop and get it diagnosed.

How can I diagnose P0656 myself using GeekOBD APP?

Using the GeekOBD APP, you can perform an OBD2 scan to retrieve codes and monitor live data. Look for voltage readings at the ECM to identify issues.

What vehicles are most commonly affected by P0656?

Vehicles commonly affected include the 2013-2017 Ford Escape and 2015-2018 Honda Civic, among others. Always check for recalls or TSBs related to your vehicle.

How can I prevent P0656 from happening again?

Regular maintenance of your vehicle's electrical system, including checking connections and wiring integrity, can help prevent P0656 from recurring.

What is P0656?

The DTC code P0656 indicates a problem with the Engine Control Module's (ECM) power supply circuit. This code typically arises when the ECM detects a voltage that is higher or lower than the expected range in the power supply circuit. In simpler terms, it means that the ECM isn't getting the proper voltage to function effectively, which can lead to various engine performance issues. Common vehicles affected by this issue include the 2013-2017 Ford Escape and 2015-2018 Honda Civic. If this code appears, you might experience symptoms like erratic engine behavior, decreased fuel efficiency, or even stalling. Ignoring this code can lead to more severe problems, including complete engine failure, as the ECM plays a crucial role in managing engine performance. It's essential to address this issue promptly by diagnosing the underlying cause and making necessary repairs to ensure your vehicle runs smoothly and reliably.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0656 is present:

  • Check engine light remains illuminated, signaling a problem with the engine management system.
  • Engine performance issues such as hesitation during acceleration or stalling, which can be alarming for the driver.
  • Fuel economy may decrease significantly, often by 10-15%, indicating that the engine isn't running optimally.
  • Unresponsive throttle, where pressing the accelerator does not produce the expected acceleration.
  • Erratic engine idle, where the engine may rev up and down unexpectedly, leading to a rough driving experience.

Possible Causes

Most common causes of P0656 (ordered by frequency):

  1. The most common cause is a faulty ECM power supply circuit, with a 70% likelihood. This can be due to damaged wiring or loose connectors.
  2. Another potential cause is a failing ECM itself, which could result from internal circuit faults, generally observed in older vehicles.
  3. A blown fuse or a corroded ground connection can also lead to this issue, making regular checks on the electrical system important.
  4. Less common but serious causes include short circuits in the wiring harness that could pose safety risks.
  5. In rare cases, software issues within the ECM may cause erroneous readings, which would require a software update or reprogramming.

P0656 Repair Costs

Cost Breakdown by Repair Type

ECM Replacement

Replacing the faulty ECM with a new or refurbished unit.

  • Total: $800 - $1500
  • Success rate: 90%
Wiring Repair

Repairing damaged wiring or connectors in the power supply circuit.

  • Total: $100 - $300
  • Success rate: 80%
Money-Saving Tips for P0656
  • 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 P0656 Diagnosis Process

Follow these systematic steps to accurately diagnose P0656. 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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
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).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Step 3: Component testing - Use a multimeter to test the voltage at the ECM connector and check for continuity in the circuit (20-30 minutes)

Step 3: Component testing - Use a multimeter to test the voltage at the ECM connector and check for continuity in the circuit (20-30 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: Step 4: System function test - After repairs, verify proper operation of the ECM and clear codes using the GeekOBD APP (10-15 minutes)

Step 4: System function test - After repairs, verify proper operation of the ECM and clear codes using the GeekOBD APP (10-15 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes)

Step 5: Road test verification - Drive the vehicle under various conditions to confirm repair success (15-20 minutes).

GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

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: 2015 Honda Civic P0656 Repair

Vehicle: 2015 Honda Civic, 60,000 miles

Problem: Customer reported check engine light and reduced fuel efficiency.

Diagnosis: After scanning with GeekOBD APP and inspecting wiring, a faulty ECM connector was found.

Solution: Replaced the connector and cleared the codes.

Cost: $250

Result: Check engine light turned off and fuel efficiency improved.

Case Study 2: 2016 Ford Escape Power Supply Issue

Vehicle: 2016 Ford Escape, 45,000 miles

Problem: Engine stalling intermittently and check engine light on.

Diagnosis: Found damaged wiring in the power supply circuit during visual inspection.

Solution: Repaired the wiring and rechecked voltage levels.

Cost: $150

Result: Vehicle running smoothly with no further issues.

Diagnose P0656

Use GeekOBD APP for professional diagnosis!

  • Real-time data monitoring
  • Advanced diagnostic features
  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0656
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes