The Seat Module (DSM or PSM) detects a voltage signal from the seat height or position sensor that is above the expected valid range (typically >4.8V). The module sets this code when the signal circuit is shorted to battery voltage or the sensor has failed internally.

Verify that the has low resistance to the chassis.

The "-87" suffix is an advanced diagnostic identifier that signifies "Missing Message." This means the primary control module (usually the Body Control Module or Central Junction Box) is expecting a specific digital signal from that switch pack but is receiving absolutely nothing.

: The wiring harness for the alarm sounder (often located behind the wheel arch liner) is notorious for rubbing against metal supports, leading to a short circuit.

The system stops functioning to protect the battery.

Intermittent chirps or non-functional lock confirmation sounds. 🔍 Common Causes

Windows or mirrors moving slightly on their own, or interior lights flickering due to erratic switch signals.

Look for spots where the wire might be rubbing against metal, which can cause a short, leading to drain. 3. Check Battery Voltage