U0100High urgency

Lost Communication With ECM / PCM

Network · CAN Bus Communication

⛔ Do not drive — multiple critical systems may be offline.
What this means

Vehicle control modules have lost communication on the CAN bus. Multiple warning lights are likely illuminated and various systems may be disabled. The cause ranges from something as simple as a blown fuse to a failed ECM module. Professional diagnostic equipment is required to accurately pinpoint this fault.

Likely causes
  • Blown fuse to ECM/PCMMost common
  • Damaged CAN bus wiring or connectorMost common
  • Failed ECM/PCM moduleCommon
  • Poor chassis ground connectionCommon
Estimated repair cost
Fuse and wiring diagnosis & repair$100 – $250
ECM/PCM replacement + programming$800 – $2,500
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Frequently asked questions

What does U0100 mean?

Vehicle control modules have lost communication on the CAN bus. Multiple warning lights are likely illuminated and various systems may be disabled. The cause ranges from something as simple as a blown fuse to a failed ECM module. Professional diagnostic equipment is required to accurately pinpoint this fault.

Is U0100 serious?

Do not drive — multiple critical systems may be offline.

How much does it cost to fix U0100?

Repair costs for U0100 range from $100 – $250 depending on the root cause and your vehicle.

Can I drive with U0100?

No — this code indicates a serious issue. Stop driving and have the vehicle inspected immediately.