U0019

Low Speed CAN Communication Bus

Q: Is it safe to drive with U0019?

Often for short trips, but if warning lights, gauges, or lighting are affected, get it checked soon — a flaky bus can disable safety-related features without warning.

Q: Can I just clear U0019?

You can, but if the wiring or module fault is still present it returns, often with more lost-communication codes across modules.

Communication network (low-speed CAN) Generic OBD-II Medium

What it means

U0019 is a fault on the low-speed CAN communication bus — the network that links body and comfort modules such as lighting, HVAC, locks, and the instrument cluster. When the bus is disrupted, those modules can't reliably share data, so features misbehave and warning lights appear. The engine usually still runs, but the cause is normally wiring, a ground, or a failed module on the bus.

Medium

Can I keep driving? Usually yes — the engine typically runs, but body and comfort features on the low-speed bus (lighting, HVAC, locks, cluster warnings) may act up or drop out.

Real-world scan data

Seen in

240

scans in the past year

Found in

<0.1%

of scans

0.1%

of scans that found faults

Appears alongside · share of U0019 scans

B210Din 30.4% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

One or more warning lights on, sometimes several at once
Body/comfort features misbehave (HVAC, interior lighting, door locks, windows)
Instrument-cluster gauges or indicators read wrong or go blank
Lost-communication (U01xx) codes stored in several modules

Common causes

Most likely first

Damaged, corroded, or loose low-speed CAN wiring or connectorsLikely
A failed module on the bus dragging the whole network downCommon
Poor ground or unstable power supply to a bus moduleCommon
Water intrusion in a connector or moduleLess often
Faulty gateway module bridging the busesLess often

How to diagnose & fix

Work through it in order

Scan every module and record all stored U-codes to see which modules dropped off the bus.
Inspect the low-speed CAN wiring, connectors, and grounds for damage or corrosion.
Check battery and charging voltage — low or unstable voltage upsets the bus.
Measure bus resistance/voltage and isolate a failed module by disconnecting suspects one at a time.
Repair the wiring or replace the confirmed faulty module, then clear and re-test.

FAQ

Quick answers

Is it safe to drive with U0019?+

Often for short trips, but if warning lights, gauges, or lighting are affected, get it checked soon — a flaky bus can disable safety-related features without warning.

Can I just clear U0019?+

You can, but if the wiring or module fault is still present it returns, often with more lost-communication codes across modules.

Read & clear U0019 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX