B1890: PAD Warning Lamp Circuit Short to Battery

What does B1890 mean?

B1890 is a diagnostic trouble code indicating "PAD Warning Lamp Circuit Short to Battery". The ECU is detecting a voltage reading that is below the expected range in the lighting circuit. This typically points to a wiring short, a faulty sensor, or a grounding issue.

Symptoms you may notice

• Check engine light (MIL) illuminated on dashboard
• Intermittent warning lights
• Erratic gauge readings

Common causes

• Damaged or corroded wiring harness
• Loose or disconnected electrical connector
• Failed lighting sensor or actuator
• Blown fuse in the related circuit
• Poor ground connection

What should you do?

This code sits in the instrument cluster or driver display. The car itself may be fine, but you can lose the speedometer, the fuel reading or the warning lights, which means the next fault the car develops may not be able to tell you about itself. Get it looked at rather than driving on a blank dash.