B2323 indicates that the driver's side mirror horizontal feedback potentiometer circuit is shorted to ground. The body control module (BCM) or power mirror control module monitors the voltage from the potentiometer to determine mirror position; when it detects a low‑impedance path to ground, it sets the code. As a result, the mirror may not move horizontally and the module will often disable that function until the fault is corrected.
The potentiometer inside the mirror assembly can develop an internal short to ground, causing the circuit to be grounded at all times.
A chafed, pinched, or broken wire in the mirror harness can expose the signal circuit to ground, creating a short.
Moisture intrusion can lead to corrosion at the mirror or BCM connector, resulting in a short between the signal pin and ground.
Rarely, the control module itself may misinterpret the signal due to an internal circuitry fault, but this is an uncommon cause.
Insufficient or unstable voltage to the mirror circuit can produce erroneous readings, though this typically generates additional codes.
No. B2323 is set by the body control module (BCM) or power mirror control module, not the engine PCM. Replacing the PCM will not resolve the issue in most cases.
The vehicle can still be driven, but the mirror may not adjust horizontally, which can reduce rearward visibility. The fault should be investigated and repaired promptly.
If corrosion is the root cause, cleaning the connector may restore proper contact and clear the code. However, if the potentiometer itself is shorted internally, cleaning alone will not fix the problem.
In many vehicles the potentiometer is integrated into the mirror motor/actuator housing and cannot be serviced separately; the whole mirror assembly typically requires replacement. Check the service parts guide for your model to confirm.