P1262 Error Code
Issue Description
The P1262 error code in Ford vehicles is described as “Cylinder 2 High to Low Side Open”. This code indicates a specific issue with the fuel injector circuit for cylinder 2, typically related to the high and low side of the fuel injector not operating as expected. The FIDM manages the fuel injectors’ high and low voltage needs, and an interruption in this circuit can lead to engine misfiring, rough idle, and performance issues.

Symptoms
When a Ford vehicle has a P1262 code, several symptoms may arise due to the disruption in fuel injection. These include:
- Check Engine Light (CEL): The most common indicator, the CEL, will illuminate on the dashboard when the P1262 code is triggered.
- Rough Idling: The engine may idle roughly due to inefficient fuel delivery to cylinder 2.
- Engine Misfire: A misfire specifically in cylinder 2 is a common symptom, as the injector is not delivering the necessary fuel.
- Reduced Engine Power: With cylinder 2 not functioning correctly, the engine’s performance will be noticeably weaker.
- Poor Fuel Efficiency: Disrupted fuel injection can lead to excessive fuel consumption, resulting in reduced fuel economy.
Causes
The P1262 error code can be caused by several factors, mainly centered around the fuel injection system and the FIDM. Key causes include:
- Faulty Fuel Injector Driver Module (FIDM): The FIDM controls fuel injector voltage levels. If it malfunctions, it may fail to operate injectors correctly, leading to cylinder-specific faults.
- Defective Fuel Injector in Cylinder 2: If the injector for cylinder 2 is damaged, worn, or clogged, it may not receive or deliver fuel properly.
- Wiring Issues in Fuel Injector Circuit: Broken, corroded, or damaged wiring can prevent the FIDM from communicating effectively with cylinder 2’s injector.
- Electrical Short or Open Circuit: An electrical short or open in the injector circuit can interrupt the high and low sides of the injector circuit.
- Low Voltage Supply to FIDM: If the FIDM is not receiving enough voltage, it may fail to operate the injectors correctly.
Diagnosing
Diagnosing the P1262 error code requires a step-by-step examination of the fuel injection system and the FIDM, focusing on cylinder 2. Here’s a general diagnostic procedure for this issue:
- Scan for Additional Trouble Codes: Use an OBD-II scanner to verify the P1262 code and check for any other codes related to fuel injection or the electrical system.
- Inspect Fuel Injector Wiring and Connectors: Conduct a visual inspection of the wiring and connectors related to the cylinder 2 fuel injector. Look for signs of corrosion, disconnection, or damage.
- Test Fuel Injector Driver Module (FIDM): Using a multimeter, test the FIDM to verify it is sending appropriate voltage to the injector for cylinder 2. Ensure the readings match Ford’s specifications.
- Check Cylinder 2 Fuel Injector Operation: Using a diagnostic tool or multimeter, test the injector for cylinder 2 to ensure it is operating correctly. A defective or clogged injector may need replacement.
- Measure Voltage Supply to FIDM: Verify that the FIDM is receiving the correct voltage supply, as insufficient power can cause injector control issues.
- Check for Shorts or Opens in Circuit: Inspect the circuit for any electrical shorts or open connections that could be interrupting power to the injector.
Solutions
Once the root cause is identified, specific solutions can be applied to resolve the P1262 error code in Ford vehicles. Here are some common solutions based on identified causes:
- Replacing the Faulty Fuel Injector Driver Module (FIDM)
- Install a New FIDM: If the FIDM is confirmed to be faulty, replacing it is the most effective solution. After replacement, test the system to ensure the new module is controlling all injectors, including cylinder 2, correctly.
- Inspect and Clear Related Codes: After replacing the FIDM, clear the P1262 code and re-scan to ensure no further codes are present.
- Repairing or Replacing the Fuel Injector for Cylinder 2
- Replace Damaged Fuel Injector: If testing reveals that the injector for cylinder 2 is defective, replace it. This should restore proper fuel delivery to the cylinder.
- Clean the Injector (if needed): In cases of minor clogging, professional cleaning of the injector may resolve the issue without replacement.
- Fixing Wiring and Electrical Issues
- Repair Damaged Wiring and Connectors: Replace or repair any damaged wiring, corrosion, or loose connections within the cylinder 2 injector circuit.
- Secure Connections and Protect Wiring: Ensure connections are secure and properly shielded to prevent future electrical faults.
- Correcting Voltage Supply Issues
- Restore Proper Voltage to FIDM: If low voltage is found, trace the source of the voltage drop and repair it, which may involve the vehicle’s battery, alternator, or wiring.
- Check the Battery and Alternator: In some cases, the vehicle’s battery or alternator may be underperforming. Ensure both components are in good working condition.
- Clearing the Error Code and Testing
- Clear the Code and Perform a Test Drive: After repairs, clear the P1262 code and perform a test drive to ensure the engine runs smoothly without any injector-related issues.
Preventive Maintenance
Preventive maintenance can help reduce the likelihood of encountering the P1262 code. Here are some maintenance tips:
- Regularly Inspect Electrical Connections: Periodic inspection of the fuel injector wiring and connectors can help prevent issues related to corrosion or disconnection.
- Use High-Quality Diesel Fuel: Poor-quality diesel can lead to clogging in injectors, so using clean, high-quality fuel can help maintain injector performance.
- Schedule Routine FIDM Checks: During maintenance, ask your mechanic to inspect the FIDM and test its voltage levels to ensure it operates within specifications.
- Replace Fuel Filters Regularly: Keeping the fuel system clean by replacing filters at the recommended intervals helps prevent contaminants from reaching and clogging injectors.