System: Powertrain (P-Code)
SAE Standard (Generic)
Family: Serial Communication Link Fault
Code P0644: Driver Display Serial Communication Circuit
Diagnostic & Technical Explanation
Code P0644 (Driver Display Serial Communication Circuit) sets when the ECM cannot communicate reliably over the vehicle's serial data network (CAN or class-2/LIN bus) with other modules or a display unit. Causes are a damaged bus wire (shorted, open, or chafed), a missing termination resistor, a module that has failed and is pulling the bus down, or a corroded ground/power connection at a networked module.
First-listed procedure
Rank #1
Check network wiring for obvious damage near recent repairs
Easy DIY
This is the first procedure in the authored
consideration order, not a measured cause likelihood. Execute it only when its prerequisites
and diagnostic findings support it. Its cost and labor estimates (where known), the step-by-step procedure and the
remaining 2 procedure(s) are in the licensed dataset. Ordering context.
Full family: Serial Communication Link Fault
What this page does not show
This page publishes the fault mechanism and the code index. The licensed dataset adds, for
every one of the 15,886 codes, the full authored repair set (56,729 procedures in total)
with the fields deliberately withheld here:
- Procedures 2..n after the first-listed procedure
- Aftermarket parts cost ranges in USD (
est_parts_cost_min/max_usd)
- Professional labor-hour estimates (
est_labor_hours)
- Step-by-step diagnostic and repair instructions
- Replacement-part mappings and catalog lookups
- 6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)