B1356 – Ignition Run Circuit Open

The ODBII code B1356 indicates that there is an open circuit in the ignition run circuit, which means that the electrical connection required for the ignition system to function properly is interrupted or not completing the circuit.

The severity of ODBII code B1356 Ignition Run Circuit Open is moderate.

Common Causes For: B1355 Ignition Run Circuit Failure

• Faulty ignition switch
• Damaged wiring or connectors
• Open circuit in the ignition run circuit
• Faulty body control module (BCM)
• Poor ground connection
• Blown fuse related to the ignition system

Common misdiagnosis for B1356 Ignition Run Circuit Open

• Faulty ignition switch
• Bad battery connections
• Defective wiring or connectors
• Malfunctioning body control module (BCM)
• Issues with the powertrain control module (PCM)
• Faulty relays
• Problems with the anti-theft system
• Defective fuses

Common Troubleshooting Steps

The OBD-II code B1356 indicates an issue with the ignition run circuit, specifically that it is open. This can lead to problems with the vehicle’s starting and electrical systems. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Vehicle’s Battery:
• Ensure the battery is fully charged and in good condition. A weak or dead battery can cause various electrical issues.
• Inspect Fuses:
• Check the fuses related to the ignition system. A blown fuse can interrupt the ignition run circuit.
• Examine Wiring and Connectors:
• Inspect the wiring and connectors associated with the ignition system for any signs of damage, corrosion, or loose connections. Pay special attention to the ignition switch and any related harnesses.
• Test the Ignition Switch:
• The ignition switch itself may be faulty. Use a multimeter to test the switch for continuity in the run position. If it does not provide continuity, it may need to be replaced.
• Check for Ground Issues:
• Ensure that all ground connections related to the ignition system are secure and free of corrosion. A poor ground can cause an open circuit.
• Scan for Additional Codes:
• Use an OBD-II scanner to check for any additional trouble codes that may provide more context or indicate related issues.
• Inspect the PCM (Powertrain Control Module):
• In some cases, the PCM may be at fault. Check for any software updates or known issues with the PCM for your specific vehicle model.
• Look for Short Circuits:
• Check for any short circuits in the wiring that could be causing the ignition run circuit to open. This may require a more in-depth inspection of the wiring harness.
• Consult Wiring Diagrams:
• Refer to the vehicle’s service manual for wiring diagrams to understand the ignition run circuit better and identify any potential problem areas.
• Perform a Visual Inspection:
• Conduct a thorough visual inspection of the engine bay and under the dashboard for any signs of wear, damage, or disconnections in the wiring. 1
• Test Components:
• If necessary, test individual components in the ignition circuit, such as relays and sensors, to ensure they are functioning correctly. 1
• Seek Professional Help:
• If the issue persists after performing these steps, it may be best to consult a professional mechanic or technician who can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the B1356 code. Always remember to take safety precautions when working on your vehicle’s electrical system.