Land Rover B1d9f11 2021 [upd] May 2026

If you are diagnosing this yourself or taking it to a shop like Land Rover Sudbury , here is the typical order of operations:

The code typically refers to the Audio Amplifier Module (AAM) .

This is the most common "fake" cause. Modern Land Rovers are notoriously sensitive to battery health. If the 12V battery is weak or has sat for too long, modules can throw false codes like B1D9F:11. land rover b1d9f11 2021

For a vehicle as recent as 2021, the fault is usually due to one of three things:

The amplifier uses an engine speed (RPM) signal for features like Active Noise Cancellation (ANC) or Speed Dependent Volume Control . If the amplifier cannot "see" this signal because the circuit is grounded, it triggers this DTC (Diagnostic Trouble Code). Common Symptoms If you are diagnosing this yourself or taking

In the Land Rover diagnostic language, code is defined as: "Engine Speed Input - Circuit short to ground" .

Multiple unrelated dashboard warnings if the fault is caused by a broader battery issue. If the 12V battery is weak or has

In some cases, the infotainment screen might have greyed-out options for radio or navigation. Primary Causes for the 2021 Model Year

The Audio Amplifier Module itself may have an internal hardware fault that is grounding the signal internally. Troubleshooting and Fixes

Distorted sound, intermittent volume changes, or the audio system failing to adjust based on speed.