The Lemon IndexThe other computers in the car stopped hearing from the engine computer.
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
Wiring or connector fault on the data network. Then: power or ground problem at the engine computer; failed engine computer.
Owners named U0100 in 84 complaints to the U.S. government, most often on the Chevrolet Silverado.
Cars owners report it on
Complaints that name U0100, by model. Raw counts, not a failure rate: popular models get more complaints.
Years owners report it on most: 2006 Dodge Charger · 2019 Chevrolet Silverado · 2006 Chrysler 300 · 2008 Toyota Prius · 2014 Ford Focus · 2020 Chevrolet Silverado
The details
What U0100 means
The other computers in the car stopped hearing from the engine computer. Features that depend on it can stop working, and several warning lights often come on together.
Can I drive with U0100?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
36% of the owner complaints that name U0100 also say the car warning lights and electrical faults. A complaint can describe more than one problem, so this doesn't prove the code caused it.
Common causes of U0100
- Wiring or connector fault on the data network
- Power or ground problem at the engine computer
- Failed engine computer
- Weak battery
A shop should confirm the cause with a scan and tests before replacing parts.
What owners describe
- Warning lights and electrical faults: 36% of complaints
- Stalls or shuts off: 30% of complaints
- Loses power or goes into limp mode: 25% of complaints
- Brakes or ABS act up: 20% of complaints
Share of complaints naming the code whose text also mentions each problem.
Model years that report U0100 most
2006 Dodge Charger (4), 2019 Chevrolet Silverado (4), 2006 Chrysler 300 (3), 2008 Toyota Prius (2), 2014 Ford Focus (2), 2020 Chevrolet Silverado (2).
Related codes
U0101 U0102 U0103 U0104 U0109 U0111 U0121 U0122
Quick answers
What does U0100 mean?
Lost Communication With ECM/PCM "A". The other computers in the car stopped hearing from the engine computer. Features that depend on it can stop working, and several warning lights often come on together.
Can I drive with U0100?
Fix soon. Book a shop visit this week. Stop driving if the car slips, shakes, overheats or warns you.
What causes U0100?
Wiring or connector fault on the data network; Power or ground problem at the engine computer; Failed engine computer; Weak battery.
Counts: NHTSA owner complaints whose text names U0100. A complaint is an owner's report, not a diagnosis. Meanings: the standard SAE J2012 definitions in our own words; manufacturer codes only where verified for that make. General information, not repair advice for your car.