Volkswagen Code P1373 – Cylinder 7 Ignition Circuit Open

Volkswagen P1373 Code Description

The Volkswagen diagnostic code P1373 indicates there is a problem with the ignition circuit of engine cylinder 7. In simpler terms, there is no electrical signal reaching the spark plug of cylinder 7, which can lead to misfires, rough idling, and poor overall engine performance. The ignition circuit is responsible for providing the high-voltage spark needed to ignite the air-fuel mixture in the combustion chamber, so any interruption in this process can have significant consequences.

Common Causes of Volkswagen P1373 Code

NOTE: The listed causes may not be a complete list of all potential problems, and there may be other causes.

1. Damaged Wiring: Exposure to heat, moisture, or physical damage can lead to wiring issues that prevent proper electricity flow to the ignition system.
2. Faulty Ignition Coil: A defective ignition coil can prevent the spark from reaching the spark plug of cylinder 7, causing ignition problems.
3. Faulty Spark Plug: A worn or defective spark plug can also disrupt the ignition process and trigger this diagnostic code.
4. ECM Issues: Problems with the engine control module, such as software issues or hardware failures, can interfere with the ignition circuit and lead to this code.

Symptoms of Volkswagen P1373 Code

1. Engine Misfires: One of the most common symptoms of an open ignition circuit in cylinder 7 is engine misfires, which can lead to rough engine operation and reduced power.
2. Rough Idling: The engine may idle roughly or unevenly if there is a problem with the ignition circuit of cylinder 7.
3. Decreased Fuel Efficiency: A faulty ignition circuit can result in incomplete combustion, leading to decreased fuel efficiency and potentially higher fuel consumption.
4. Check Engine Light: The vehicle’s onboard diagnostic system may detect the issue and trigger the check engine light to alert the driver of a problem.

How to Fix Volkswagen P1373 Code

1. Diagnose the Problem: Use a diagnostic tool to identify the exact cause of the issue, whether it’s a wiring problem, faulty component, or ECM malfunction.
2. Inspect and Repair Wiring: Check the wiring harness for any visible damage or breaks, and repair or replace it as necessary.
3. Test the Ignition Coil and Spark Plug: Verify the operation of the ignition coil and spark plug in cylinder 7 and replace them if needed.
4. Check the ECM: If all other components are correct, inspect the engine control module for any potential faults or errors, and reprogram or replace it if necessary.
5. Clear Codes and Perform a Road Test: Clear the diagnostic codes from the vehicle’s computer and perform a road test to ensure the issue has been resolved.