P1686 – Acura DTC

Acura DTC P1686 – A/T FI Signal B Low Input

DTC P1686 meaning on Acura

DTC P1686 on an Acura indicates a low input signal from the Automatic Transmission Fuel Injection (A/T FI) system. This code is specific to the A/T FI signal B, which is used by the engine control module to manage fuel injection timing in coordination with the automatic transmission system.

Acura DTC P1686 symptoms

Symptoms of DTC P1686 on an Acura may include issues with shifting gears smoothly, poor acceleration, decreased fuel efficiency, and in some cases, the vehicle may go into a limp mode where it operates at reduced power.

Acura DTC P1686 causes

The low input signal for A/T FI Signal B in an Acura can be caused by various factors such as a faulty A/T FI sensor, damaged wiring or connectors in the A/T FI circuit, or issues with the engine control module itself.

Acura DTC P1686 seriousness

While DTC P1686 may not cause immediate safety concerns, it can lead to drivability issues and potentially affect the overall performance of the vehicle. It is recommended to address this code promptly to prevent further damage to the transmission or engine components.

How to diagnose DTC P1686 on Acura

To diagnose DTC P1686 on an Acura, a mechanic would typically start by using a diagnostic scanner to retrieve the specific fault codes. They would then inspect the A/T FI sensor, check the wiring and connectors for any damage or corrosion, and perform tests to ensure proper signal continuity.

How to fix DTC P1686 on Acura

Fixing DTC P1686 on an Acura may involve replacing the faulty A/T FI sensor, repairing any damaged wiring or connectors, or reprogramming the engine control module if necessary. It is important to follow the manufacturer’s diagnostic and repair procedures to ensure a proper fix.

How to erase DTC P1686 on Acura

Once the underlying issue causing DTC P1686 on an Acura has been resolved, the fault codes can be cleared using a diagnostic scanner. This will reset the check engine light and allow the vehicle’s systems to retest and confirm that the problem has been fixed.

Recommended tools for Acura diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.