P0644: Driver Display Serial Communication Circuit

What does P0644 mean?

P0644 is a diagnostic trouble code indicating "Driver Display Serial Communication Circuit". This code relates to your vehicle's engine electronics and should be diagnosed to determine the root cause. The severity level helps indicate how urgently this should be addressed.

Symptoms you may notice

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

Common causes

• Faulty engine electronics component
• Wiring or connector issue in the related circuit
• Failed sensor providing incorrect readings
• Software/calibration issue requiring ECU update
• Related component causing secondary fault

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.