Critical Safety risk Network-code
U0100
U0100
Lost Communication With ECM/PCM "A"
Pull over safely and book service immediately
This code is flagged as a safety risk and rated Critical. Avoid driving until a technician has inspected the vehicle.
Symptoms
- No symptoms documented
Likely causes
Causes vary by vehicle. A technician will run targeted diagnostics.
Labor estimate
2h typical
Range: 1h – 4h
Parts cost
$0 – $500
Range varies by year/make/model
Information shown is reference-grade and may vary by vehicle. Always have a qualified technician confirm the cause before any repair.