Nissan Error Code P1605: How to Fix It

Q: What does Nissan error code P1605 mean?

P1605 indicates a communication problem between the engine control module (ECM) and transmission control module (TCM). The diagnostic communication line that allows these modules to share information is not working properly.

Q: Can I drive with P1605 error code?

While the vehicle may still be drivable, P1605 can cause transmission shifting problems, reduced fuel economy, and potential damage to transmission components. It's best to diagnose and fix this issue promptly.

Q: How much does it cost to fix P1605?

Repair costs vary widely depending on the root cause. Simple wiring repairs may cost $100-300, while TCM or ECM replacement can cost $800-2000 including labor. Start with basic diagnostics to identify the exact problem.

Q: What causes P1605 in Nissan vehicles?

Common causes include damaged wiring harnesses, corroded connectors, poor ground connections, failed TCM or ECM modules, or internal transmission problems that affect communication circuits.

Q: Will P1605 cause transmission failure?

While P1605 itself indicates a communication issue, the underlying problem (such as internal transmission damage) could lead to transmission failure if not addressed. Proper diagnosis is essential to determine the severity.

Abstract

Nissan error code P1605 indicates a problem with the AT (Automatic Transmission) diagnostic communication line. This error means the engine control module (ECM) cannot properly communicate with the transmission control module (TCM), which can cause transmission shifting issues and poor vehicle performance.