Volkswagen Code P1377 – Cylinder 8 Ignition Circuit Short to B+

Volkswagen P1377 Code Description

The diagnostic trouble code P1377 (DTC) for Volkswagen vehicles indicates a short to battery positive (B+) in the ignition circuit for cylinder 8. This issue can disrupt the proper operation of the ignition system, leading to poor engine performance, misfires, and potentially even engine damage if left unresolved.

Common Causes of Volkswagen P1377 Code

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

1. Faulty ignition coil: A defective ignition coil can cause a short circuit in the ignition circuit for cylinder 8.
2. Damaged wiring: Frayed or damaged wiring in the ignition circuit can cause a short to the battery positive terminal.
3. Faulty ECM: A defective engine control module may incorrectly detect a short circuit in the ignition circuit.
4. Corrosion: Corrosion on electrical connectors or terminals can create a poor connection, leading to a short circuit.

Symptoms of Volkswagen P1377 Code

1. Rough idle: A short circuit in the ignition circuit can cause a rough idle as the engine struggles to maintain a steady rhythm.
2. Misfires: Cylinder misfires are common when a short circuit affects the ignition system, resulting in a lack of combustion in cylinder 8.
3. Decreased fuel efficiency: A faulty ignition system can lead to inefficient engine operation, resulting in reduced fuel economy.
4. Check engine light: Illumination of the check engine light is a common symptom when the P1377 code is triggered.

How to Fix Volkswagen P1377 Code

1. Diagnose the problem: Use a scan tool to read DTCs and identify the exact cause of the short circuit.
2. Inspect wiring and connectors: Check the ignition coil, wiring harness, and connectors for any signs of damage or corrosion.
3. Replace faulty components: If a defective ignition coil or damaged wiring is found, replace the affected parts.
4. Clear codes: After completing repairs, clear the DTCs and reset the ECM to ensure the check engine light turns off.
5. Road test: Perform a road test of the vehicle to verify that the issue has been resolved and the engine is running properly.