Severity Medium
B2321

Driver Mirror Horizontal Feedback Open

📅 Last reviewed: July 2026
What does the B2321 code mean?

The driver seat module (DSM) or body control module (BCM) has detected an open circuit in the horizontal feedback potentiometer of the driver-side mirror. This sensor reports the mirror's exact position for memory and auto-fold functions. An open circuit prevents the module from knowing the current position, disabling the return to stored positions.

Medium
Severity
Variable
Typical Cost
Medium
Frequency

1. Commonly Affected Makes

FordLincolnMercury

2. Most Common Causes

3. Symptoms You Will Notice

4. Step-by-Step Diagnosis

1

Check for technical service bulletins (TSBs) related to mirror feedback circuits.

2

Inspect the mirror and module connectors for corrosion, damage, or loose pins.

3

Test the horizontal feedback potentiometer resistance between signal and ground; compare to specifications.

4

Verify 5V reference and ground at the mirror connector with the ignition on.

5

If wiring and potentiometer are good, suspect a faulty DSM or door module.

5. Frequently Asked Questions

Is it safe to drive?

Yes, the vehicle remains safe to drive. The mirror may not return to its saved position or fold automatically, but manual adjustment still works.

How much does it cost to fix?

Repair costs typically range from $150 to $400, depending on whether the mirror assembly or module needs replacement and labor rates.

6. Related Codes

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