Code result
P0644
Driver Display Serial Communication Circuit
Moderate severity
What it means
The serial communication line to the driver display (instrument cluster, MIL/check-engine warning) shows a circuit fault. Driver may not see warning lights as expected.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Harness or driver fault
highOne of the most commonly reported causes for this code — check this first.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
CAN terminating resistor (120 Ω) drifted out of spec
lowLess common, but worth ruling out after the more likely causes.
Related help
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